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INDEX Aquaculture Magazine Volume 40 Number 3 June - July 2014

Editorial.....................................................................................................................................................................2 Photo credit: Jeff Milisen © Kampachi Farms, LLC

on the

64 cover

A call to Action: Mariculture could provide 2/3 of food fish consumption by 2030.


report Potential of Crassostrea gigas as a bio indicator of the presence of white spot syndrome virus (WSSV) in shrimp farms.


research report Haemolymph microbiota of bivalves as a pertinent source of probiotics for aquaculture.

ASIAN report


Aquaculture in Regional Australia: Responding to Trade Externalities.



REPORT Conservation Aquaculture; Restoring the Ancient Alligator Gar.


Effect of Brand Equity across Seafood Products.


REPORT Brazilian Aquaculture; a Seafood Industry Giant in the Making.


Perfect Seafood Portioning.


research report Effect of oxidation–reduction potential on performance of European sea bass in RAS systems.


I-Cut 130 PortionCutter for the salmon industry.


research report Toxic Effects of Antiparasitic Pesticides Used by Salmon Industry in Monocorophium insidiosum.


report Aquaculture still growing.


NEWS ARTICLE World’s largest SPF shrimp broodstock supplier ramps up in Hawaii.



Columns Feed Report ..............................................................................58 ShrimP ..............................................................................60 Marine Finfish Aquaculture.......................................................................62 Offshore Aquaculture .............................................................................64 Latin AmericaN Report ...................................................................................67 Genetics and Breeding ..................................................................................68 European Report ...............................................................................72 Shellfish ..............................................................................74 Upcoming events advertisers Index

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Chile prepares to host the largest aquaculture trade show in the Southern Hemisphere In October 2014.

Volume 40 Number 3 June - July 2014 Editor and Publisher Salvador Meza / Editor in Chief Greg Lutz / Managing Editor Mina Coronado / Editorial Design Francisco Cibrián / Designer Perla E. Neri Orozco / International Sales and Marketing Steve Reynolds / Business Operation Manager Adriana Zayas Subscriptions: Design Publications International Inc. 203 S. St. Mary’s St. Ste. 160 San Antonio, TX 78205, USA Office: +210 229-9036 Office in Mexico: (+52) (33) 3632 2355 Aquaculture Magazine (ISSN 0199-1388) is published bimontly, by Design Publications International Inc. All rights reserved. Follow us:



By C. Greg Lutz


ne thing is obvious as I scan through this issue of Aquaculture Magazine… we do not have exclusive insights into aquaculture here in North America. A lot is going on, in a lot of places throughout the globe. Production, policy and marketing are universal issues that test the resolve of our counterparts in other parts of the world just as much as they challenge us here at home. And while good work is going on in research, extension and promotion here in North America, our colleagues elsewhere are also coming up with novel approaches to solve common problems. As globalization advances, no-one can afford to lose touch with what is going on – either just down the road or on the other side of the planet. And overall, this is a good thing because it provides opportunities to learn from others in terms of shared concerns and unique experiences. 2 »

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Speaking of novel approaches, I was fascinated by some of the research results you will find in this issue. Who would have imagined that oysters (which I used to find kind of boring, I am embarrassed to admit) might become powerful tools in combatting diseases in other aquatic species? Novel approaches are also evident in the arena of feedstuffs – where aquaculture already has significant advantages over traditional livestock in terms of efficiency and sustainability. Interactions between aquaculture species, production practices and the environment we operate in are often far more complex than we or our critics might want to consider (note the article on parasite control in salmon) but in terms of sustainability and conservation, aquaculture offers far more solutions than problems (as in the case of restoring threatened species such as alligator gar). Reflecting on global issues and advances also serves as a reminder

that there will always be competition, and highlights the need for maintaining and improving our competitive positions as producers, commodity groups, and as an entire industry. This, ultimately, is what Aquaculture Magazine strives for in each issue. Our columns this issue include updates and insight on topics including marine finfish, shellfish production, offshore aquaculture, shrimp culture, and genetics, with some interesting reports from Latin America and Europe. As always, feel free to contact us with questions, comments and suggestions at editorinchief@dpinternationalinc. com – we enjoy hearing from you!

Dr. C. Greg Lutz has a B.A. in Biology and Spanish by the Earlham College at Richmond, Indiana, a M.S. in Fisheries and a Ph.D. in Wildlife and Fisheries Science by the Louisiana State University. His interests include recirculating system technology and population dynamics, quantitative genetics and multivariate analyses and the use of web based technology for result-demonstration methods.

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Potential of Crassostrea gigas as a bio indicator of the presence of white spot syndrome virus (WSSV) in shrimp farms

One of the main problems in the struggle against the White Spot Syndrome Virus (WSSV) around the world is the difficulty in detecting the presence of this virus in ponds before it spreads into cultivated By Celia VĂĄzquez Boucard*



esearchers do not yet understand how WSSV moves before, during and after epizootic events. Mortality rates that can affect 100% of production occur between 3 and 10 days after the confirmed appearance of the first symptoms of this disease. Analyses designed to detect this virus, which are performed routinely in shrimp production ponds, fail to detect it opportunely before it produces infections. Thus, it catches fish-farmers off-guard and gives them no opportunity to implement precautionary measures or disinfect their ponds. Moreover, there are no treatments guaranteed to fight infection, so when WSSV invades production ponds and replicates there it quickly becomes uncontrollable. The only option is to reduce or control its entry, but this requires early detection. Various studies have identified aquatic routes as the main access of this virus into production ponds, perhaps freely, or in association with planktonic sub-populations such as microplankton, nanoplankton or picoplankton. 4 Âť

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Photo courtesy of:

Oysters and WSSV Oysters are excellent sentinel organisms capable of detecting the presence and effects of contaminant molecules in aquatic environments. Bivalve mollusks have been utilized for several years now in France, the U.S.A. and other countries as sentinel organisms that monitor environmental systems in order to detect the presence of chemical compounds in aquatic media. These organisms possess a high filtration capacity that allows them to accumulate diverse suspended particles that may then be transported into their digestive systems during feeding. These particles include pesticides, heavy metals, and bacteria, parasites and viruses impacting humans. Thanks to the timely detection of WSSV in gills and digestive glands of sentinel oysters placed in the entry canals to shrimp farms in an experiment performed in 2011, researchers from the Center for the Northwest Biological Research (CIBNOR, La Paz, Mexico) decided to design an early detection and alarm system for the presence of WSSV that uses the species’ bioaccumulation capacity. In order to do this, it was essential to determine the relationship between the oyster and the virus, since it was necessary to eliminate the possibility that they might act as vectors that propagate it. Materials and methods WSSV-free C. gigas oysters and Litopenaeus vannamei were immersed for 3 days in ponds in which low concentrations of WSSV inoculum were dissolved. Virus was detected by PCR nesting in the oysters just 24 hours after initiating the experiment, and was identified in both the gills and digestive gland. During the month required for the challenge trial, shrimp presented no signs of infection, demonstrating that the low concentrations of WSSV in the aquatic medium were non-infective for them, but were retained and were detectable in

the oysters’ gills and digestive glands. Classic histological analysis (with hematoxylin-eosin stain) and in situ hybridization conducted with the gills and digestive gland of C. gigas tested positive for WSSV and demonstrated the absence of viral inclusions and intracellular precipitates in those tissues. These findings proved that this oyster is not susceptible to the virus. In order to determine whether C.gigas oysters are able to retain viral particles released by infected L. vannamei shrimp, WSSV-free oysters and shrimp injected intramuscularly with this virus were immersed in co-habitation in ponds with synthetic seawater that was also virus-free. After 24, 36 and 48 hours post-immersion, the study detected mortality in shrimp and the presence of WSSV in the gills and digestive glands of the oysters. The results obtained indicated that the shrimp infected with WSSV dispersed the virus in the aquatic medium, and that it accumulated in the gills and digestive glands of the C.gigas oysters, such that it was detected in the gills after 24 hours of co-habitation, and after 48 hours in the digestive gland.

The study recorded no propagation of WSSV released by C. gigas into the aquatic medium. Both C. gigas oysters inoculated with the virus and WSSV-free oysters were immersed in co-habitation in order to determine whether the oysters injected with the virus released it into the aquatic medium. During the 7 days of this experiment, no WSSV was detected in the oysters that were free of the virus.

Oysters as bioindicators of viruses’ presence A total of 720 C. gigas oysters from a farm in Santo Domingo, Baja California Sur, on Mexico’s Pacific coast were placed in the water entry canal of the pumping station of a shrimp farm in El Dorado, state of Sinaloa. Before being shipped to Sinaloa, oysters were culled for 10 days in 2 ponds equipped with open water circuits. The sentinel system consisted of 3 modules, each equipped with 3 polypropylene boxes. A total of 80 oysters were placed in each box. On day 6 post-placement of the organisms, and on every second day afterwards, 20 oysters were gathered. A total of 28 collections took place

M 1

(-) (+) 2








10 11 12 13 14 15




19 20 21

600 pb 500 pb


(-) (+)

600 pb 500 pb



24 25

26 27 28 29 30 31 32 33 34 35 36


38 39

40 41 42

Fig. 1. Crassostrea gigas. Agarose gel showing the white spot syndrome virus (WSSV) nested PCR product amplified from oysters immersed in seawater containing 4 ID50 ml−1 WSSV inoculum (Bioassay 1). Lanes 1, 22: DNA size markers; Lanes 2−19: gill DNA from 18 oysters; Lanes 23−40: digestive gland DNA from the same oysters; Lanes 21, 42: WSSV DNA positive control; Lanes 20, 41: negative controls (water).

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Chinese (GenBank NC 003225.1), and Taiwanese WSSV (GenBank AF440570.1). The amplicon sequenced in this study also had an identity of 99% with the sequence reported in plankton collected from a shrimp farm in Guasave, Sinaloa (GenBank FJ609650.1), and an identity of 99% with the viral DNA of infected shrimp on that same farm (GenBank FJ789570.1). On April 19th, the study detected this infection at the farm selected for monitoring. The following day, mortality of shrimp reached 50%. C.gigas oysters placed as sentinels at the entrance of the water feeder into the farm detected the presence of the virus 16, 13 and 11 days before the infectious event was triggered in ponds. WSSV was not detected in oysters recovered before April 3rd (March 23rd-30th), or after April 8th (April 11th-May 25th). Also, no infectious event was recorded on those dates at the farm.

Fig. 2. Crassostrea gigas. Light microscopy images of gill tissues from an oyster cohabitated with white spot syndrome virus (WSSV)-infected Litopenaeus vannamei shrimp at 72 h that tested positive for WSSV by nested PCR. Histological tissue sections were examined either by (A−D) in situ hybridization (ISH) or (E,F) haematoxylin and eosin (H&E) staining. (A,B) ISH signal (arrows) in filaments. (B,C) Absence of ISH signal from vesicular connective tissue and basal lamina. (D) Presence of ISH signal in inter-filament spaces. (E,F) No evidence of hypertrophied cell nuclei or WSSV inclusion bodies in vesicular connective tissue and basal lamina. Bf: branchial filament; Ct: vesi cular connective tissue; m: mucocytes; Dm: demibranch of gill; Bl: basal lamina. Scale bars = (A,B,C,E,F) 100 μm, (D) 10 μm

during the period from March 23 to May 25, 2010. All samples were taken randomly from the different modules. Organisms were collected, frozen while alive, and sent to the Biochemical and Molecular Biomedicine Laboratory at the CIBNOR and the Autonomous University of Nayarit to perform analyses designed to detect WSSV using nested PCR. Control lots were also analyzed; one composed of 20 oysters gathered before the others were sent to Sinaloa, and the second collected before the sentinels were placed on the farm to begin monitoring. 6 »

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The diagnosis of WSSV by nested PCR only detected the presence of the viral DNA of WSSV in three of the collections conducted on April 3rd, 6th and 8th 2010, at percentages of 15%, 20% and 55%, respectively, in the oysters analyzed. An amplicon of 570 pb was obtained, which corresponds to the size expected for the product amplified by the pair of oligos PK3/PK4. The PCR products from the gills of oysters were sequenced, and an identity of 99% was found with the segment isolated from the genome of the Thai (GenBank access number AF369029.2),

Discussion Results show that sentinel oysters are capable of detecting the entrance of WSSV in ponds at least 16 days before infection is produced, thus conferring to this species of bivalve mollusk a potential value for utilization in early detection systems of this virus on shrimp farms. The possibility that the period that transpired between the alert and the outbreak of infection might depend on the status of the immune system of the

Sentinel oysters are capable of detecting the entrance of WSSV in ponds at least 16 days before infection is produced.

cultivated shrimp, or on some still undetermined environmental factor that may trigger this disease cannot be discarded. Bivalve mollusks have developed an efficient water filtration system with a filtration index of up to 1l/ hour per gram of tissue. This allows the selective capture of suspended material that can range in size from 1-10 µm through specialized gill structures; though this varies according to the concentration of dissolved particles, environmental factors, and the size of the animals themselves. The high filtration and particlecapturing indexes that characterize these organisms mean that they are carriers of certain bacteria and virus that they absorb from contaminated waters; though they rarely become infected. Histological analyses conducted during this study proved that C.gigas is not susceptible to WSSV. As occurs in polychaetes, this oyster could be used as a carrier species capable of contaminating other organisms if ingested. In the experimental bio-assays carried out, oysters were fed throughout the experimentation period with a daily ration of microalgae Isochrysis galbana. Different planktonic compounds, such as rotifers, copepods and algae, have been cited as poten-

C.gigas oysters retain viral particles of WSSV present in an aquatic medium in gills and digestive glands. Additionally, this bivalve is not susceptible to the virus and it’s a potential bioindicator of the presence of virus in water entry canals. tial carriers and reservoirs of WSSV, and it is known that WSSV adhered to phytoplankton is a route of transmission for this disease in species of zooplankton (rotifer Brachionus urceus; copepod Acartia clausi and shrimp Neamysis awatschensis). Experimental bio-assays conducted with such marine microalgae as Chlorella sp., Scrippsiella trochoidea, Isochiris galbana and Heterosigma akashiwo showed that plankton functioned as a carrier and could indeed infect exposed shrimp. Organisms exposed to WSSVpositive Nitocra sp. copepods became transmitters of the virus. Therefore, it is possible that C.gigas oysters retain the virus in the mucosa of the gills by adherence to plankton, and then conduct it to the digestive gland. A study related to the mechanisms of retention of other virus by C.gigas oysters showed that this process involves adhesion of the virus to the mucous secreted and ingested by these mollusks during feeding.

The mechanisms that C.gigas oysters employ to eliminate WSSV remain unknown, and this is a matter of some concern since when placed as sentinels they might actually serve as vectors for WSSV. For this reason, an additional part of this study was also carried out using a co-habitation bioassay with oysters inoculated intramuscularly with WSSV and others that were virus-free. During the 7 days of this experimental period, there was no evidence that virus-free oysters accumulated viral particles. However, further studies are required to evaluate this virus’ capacity to bond to cells of the oysters, and to determine the ability of the latter organisms to cull the bio-accumulated viral particles.

*For more information please contact Dra. Celia Vázquez Boucard. Centro de Investigaciones Biologicas del Noroeste(CIBNOR), La Paz, BCS, Mexico. E-mail

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research report

Haemolymph microbiota

of bivalves as a pertinent source of probiotics for aquaculture The present article shows the results of a trial where haemolymphassociated microbiota of four marine bivalve species was explored for By Florie Desriac, Patrick Le Chevalier, Benjamin Brillet, Ivan Leguerinel, Benoît Thuillier, Christine Paillard and Yannick Fleury*


he ‘hologenome’ concept considers the host and its associated microorganisms (microbiota) a super-organism (holobiont) and therefore the true evolutionary unit of selection. This concept is based on (1) existing symbiotic relationships between all animals or plants and several microorganisms; (2) the transmission of the symbiotes; (3) the benefits of the symbiotic association between the host and the microorganisms; and (4) the genetic plasticity enhancement of the holobiont, through change in the microbiotic composition under environmental pressure. The ‘hologenome’ theory strengthens the probiotic concept. Microbiota may form a microbial shield that could limit the settlement of pathogens by competition for resources and/or antimicrobial compound production and/or stimulation of the host immune system. Microbiota antimicrobial compounds seem to play a key role in control of the microbial community and health recovery. As environmental pressures such as climate changes can disturb 8 »

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antibacterial activity against important aquaculture pathogens, giving a first insight into the contribution of haemolymph-associated microbiota as part of the bivalve “hologenome”. the microbial shield, allowing epizootic events in marine invertebrates, antimicrobial compounds from autochthonous probiotics could be a powerful tool to restore the microbial shield and protect the host from pathogens. Marine invertebrates and especially bivalves may be considered pertinent animal models since they are filter-feeders and so have to face large numbers of microorganisms. Furthermore, the well-accepted presence of microorganisms in the haemolymph of healthy bivalves tends to indicate that this ecosystem could contribute to host hemostasis. The haemolymph-associated microbiota has been mainly investigated for pathogens, whereas its composition and role remain obscure. Researchers have recently isolated antimicrobial compound-producing strains from oyster haemolymph, suggesting that microbiota may confer a health benefit on the host. In this study, researchers explored the cultivable haemolymph-associated bacteria in four bivalves (oyster, clam, mussel and scallop) for their antimicrobial

activity. The most potent ones were also investigated for hemocyte cytotoxicity.

Materials and methods To limit the impact of anthropic pressure, bivalve specimens were collected by deep-sea diving in the Glenan Archipelago (France), during winter 2009 and spring 2010. Selected species were oyster (Crassostrea gigas), blue mussel (Mytilus edulis), scallop (Pecten maximus), and pink clam (Tapes rhomboides). Haemolymph of each individual was collected aseptically by inserting a 25-gauge needle attached to a 1 ml syringe directly into the adductor muscle. For C. gigas, haemolymph was collected from the pericardium. A volume ranging from 0.5-1 ml of haemolymph was drawn from each mollusk and placed in ice to prevent the hemocyte aggregation. Each sample was microscopically examined to check the presence of healthy hemocytes. Bacteria isolation Checked haemolymph (50 μl) was

spread onto Marine agar Petri dishes using an automated spiral plate. Plates were further incubated for 72 hours at 18°C. To isolate as many different bacteria as possible, 1–10 macroscopically distinguishable colonies were picked and sub-cultured in Marine Broth for 48 hours at 18°C with shaking (100 rpm). Bacterial purity was assessed by streaking on Marine Agar. For long-term storage, sterile glycerol was added to 1 ml bacterial culture (25% v/v) in cryogenic vials that were stored at -80°C.

Antimicrobial assay Cell-free supernatants coming from culturable haemolymph-associated bacteria were assayed for antibacterial activity against a panel of 12 aquaculture pathogens (Table 1). After growth (72 hours, 18°C, 100 rpm), the culture supernatant (1 ml) was collected by centrifugation (6,000 g for 10 min. at 4°C) and filtration (0.22 μm, SFCA serum). To detect antibacterial activity, the well-diffusion method was used.

Specific agar medium according to bacterial target was inoculated with an 8-hour-old culture broth of the indicator strain to a bacterial concentration of 1.106 CFU/ml_1. Wells (diameter 4 mm) were punched into the agar medium and cell-free supernatants (20 μl) or controls (Marine Broth for negative control and polymyxin B sulphate and Nisaplin® at 1 mg/ml_1 as positive control against respectively Gramnegative and Gram-positive target bacteria) were created. After an overnight incubation at optimal growth temperature of the indicator strain, antibacterial activity was revealed by an inhibition halo around wells. When antibacterial activity was detected, a second antibacterial assay in liquid medium was performed to define minimal inhibitory concentrations in standard 96-well micro-titer plates. Briefly, target bacteria in exponential growth state (1 × 106 CFU/ml_1) were incubated with serial twofold dilutions (in sterilized Marine Broth) of active cell-free supernatant and incu-

bated for 48 hours at optimal growth temperature. Sterile as well as growth and inhibition controls (Polymyxin B at 100 μg/ml_1) were carried out. The activity was expressed as a function of protein concentrations (μg/ml_1) as a function of the highest dilution factor of cell-free supernatant that inhibited 100% of the target strain growth. The target bacteria panel was broadened. Five other strains of Vibrio were included: Vibrio pectenecidae A365,V. coralliilyticus CIP107925, V. tubiashii CIP102760, V. parahaemolyticus and V. harveyi ORM4.

DNA extraction and 16S PCR The bacterial isolates expressing antibacterial activity were selected for a phylogenetic analysis based on 16S rRNA gene sequences. DNA was extracted as previously described and 16S rRNA gene was amplified using two universal primers, W18 : 9F and W20 : 1462R, yielding 1000–1500 pb PCR products. The following PCR conditions were used: initial denatur-

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research report

ation at 94°C for 4 min., followed by 35 cycles at 94°C for 1 min., 52°C for 1 min. and 72°C for 1 min. and a final elongation step at 72°C for 10 min. The PCR products were analyzed on agarose (1.2%) gel electrophoresis and sequenced. Sequences were compared with the GenBank nr/nt database by BLASTN to identify their closest match. To construct trees, an alignment with the first five hit BLAST 16S sequences of each strain was made, using CLUSTALW2. Phylogenetic trees were built using MEGA 5 program package.

an appropriate volume of sterile seawater before contact. Following incubation, propidium iodide (1% v/v) was added and hemocytes incubated in the dark for an additional 30 min. Samples were then analyzed with a flow cytometer. The measures were obtained after 30 seconds with a low flow rate. The three replicate data collected were then statistically analyzed by a one-way ANOVA, with P-error level set at 0.05.

of Tapes rhomboides collected) than in haemolymph from fixed bivalves (9% of C. gigas and M. edulis collected). Excluding these extreme bacterial concentrations, the highest average bacterial concentration was detected in M. edulis haemolymph and the lowest one in P. maximus. The culturable haemolymph-associated bacterial concentrations were shown to be individualand species-dependent. This may be the result of various environmental concentrations as well as bivalve physiological characteristics. Moreover, growth conditions (MB medium and incubation temperature) may clearly impact the bacterial growth rate and/ or select some marine species. A total of 843 haemolymph-associated strains were isolated from the bivalve haemolymph sampling. They were named according to their origin and the number of the isolate.

Antibiotic sensitivity The sensitivity to antibiotics was determined by a disc-diffusion method, Cytotoxicity assay with Marine Agar plate as medium due The cytotoxicity activity was esti- to marine bacteria cultivability. Antimated for three active strains isolated biotics tested were amoxicillin (25 μg), from oyster haemolymph. The two colistin (50 μg), enroflaxin (5 μg), floantimicrobial compound-producing rfenicol (30 μg), flumequin (30 μg), tetstrains, named hCg-6 and hCg-42, iso- racycline (30 UI) and trimethroprim/ lated from oyster haemolymph in a sulphamethoxazole (1.25/23.75 μg). previous study, were also investigated Results were observed after an 18–20for hemocyte cytotoxic effect. Briefly, hour incubation at 18°C. Screening for antibacterial the haemolymph of about 30 C. gigas activity was withdrawn, pooled and filtered Results and discussion The 843 isolates were screened for through an 80-μm mesh. A 19-hour- The haemolymph from oysters, clams, antibacterial activity against 12 target long contact was established at 18°C mussels and scallops were spread onto bacteria by the well-diffusion assay. between hemocytes and bacteria in non-selective Marine Agar. A great Among these, 26 isolates (about 3%) cytometry tubes. Several concentra- disparity in culturable haemolymph- showed a clear inhibition zone around tions of bacteria were evaluated (ra- associated bacteria was observed intra wells for at least one target strain. The tio bacteria/bivalve hemocytes 25:1, host species. Haemolymph bacterial antibacterial activity was exclusively 50:1, 100:1). A control was done using concentrations below the lower limit directed against Gram-negative bacteincubated hemocytes in sterile seawa- of detection (i.e. 102 CFU/ml_1) were ria, mostly of the Vibrio genus. Such ter. Bacteria were washed three times more frequently observed in mobile selectivity of activity differs from the with sterile seawater and suspended in bivalve (75% of P. maximus and 51% antibacterial spectra usually described

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during marine antibiotic screenings. Indeed, Gram-positive target bacteria generally appear to be more sensitive. Data suggest that haemolymphassociated bacteria may constitute a specific microbiota tolerated and/or selected by host for their ability to inhibit pathogens. On the other hand, despite a high number of isolates, no strain isolated from clam haemolymph demonstrated antibacterial activity. The target bacteria spectrum and/or the growth conditions (nutrients and/or temperature or bacterial presence in the surroundings) may explain these results. Nonetheless, the potential of bivalve microbiota as a source of antimicrobial compounds is evident, although underexplored. The cryogenic storage resulted in total loss of cultivability for five strains (hMe-15, -22, -82, -119 and -131) and the cell-free supernatant of a further nine strains did not exhibit antibacterial activity (hCg-60, -78, -111 and114, hPm-100 and -102, hMe-34, -43 and -273). Such loss of cultivability or bioactivity after storage is frequently described with marine bacteria.

tration (Table 2). All the hCg strains and hMe-187 and -253 supernatants were able to inhibit 100% of bacterial growth of at least one pathogen when diluted at least 64-fold. Moreover, eight haemolymph-associated isolates inhibited at least five different species among the seven Vibrio species included in the panel and one or more other bacteria, suggesting a real potential for antibacterial treatment in aquaculture farming, since Vibrio species are pathogenic for fish, mollusks and crustaceans.

Active haemolymph-associated bacteria identification The active haemolymph-associated strains, hCg-23, -48, -51, -108, -109, hPm-26, hMe-95, -223, -253 and -273, were identified by 16S rRNA gene amplification as members of the Gammaproteobacteria class belonging to either the Alteromonadales (89%) or the Vibrionales orders (11%). Such affiliation was also observed in antimicrobial screening of marine bacteria and in previously described probiotics used in bivalve hatcheries. Vibrio genus has been described to be a natural flora in bivalve and crustacean haemolymph. Antibacterial potency evaluation Nine strains, hCg-23, -48, -51, -108, The antibacterial activity of the 12 -109, hMe-95, -223, -253 and -273, bioactive strains remaining was quan- were affiliated with the Pseudoalteromotified using a 96-well micro-titration nas genus. One set of bacteria, hCgmethod. Insofar as the chemical na- 23, -48, -51, -108 and -109, formed ture of the active compounds was a new cluster in the Pseudoalteromonas unknown, MICs were expressed as a genus. This genus is well-known to function of maximal dilution factor produce a wide variety of biologically of the supernatant that exerted a total active secondary metabolites. Within inhibition of pathogen growth. MICs this genus, the strains Pseudoalteromowere also expressed in protein concen- nas haloplanktis INH, Pseudoalteromonas

Results suggest that haemolymph microbiota may participate in bivalve protection and therefore confer a health benefit on the host. sp. X153 and Pseudoalteromonas sp. D41 were shown to protect or enhance the survival rate of Agropecten purpuratus, P. maximus and C. gigas, respectively. Some of the haemolymphatic strains are within lineages that are phylogenetically distinct from known probiotic strains and may have unique probiotic properties (e.g. secondary metabolites). As no antibacterial activities have ever been described in species closely related to the isolated strains, it is postulated that the antibacterial compounds produced by these strains have not been described to date. Nonetheless, the hPm-26 bacterial strain isolated from P. maximus haemolymph was affiliated within the genus Thalassomonas. To researchers’ knowledge, this is the first report describing antibacterial activity from the recent genus Thalassomonas.

Hemocyte protection of the haemolymph-associated bacteria Due to their potent antibacterial activities, three strains of Pseudoalteromonas were investigated for their impact on oyster hemocyte survival in vitro. Goal was to control the safety of hCg strains toward hemocytes. Indeed, although the bivalves collected were healthy, there was no guarantee that a high concentration of the bacteria would not result in hemocyte death. Hemocytes were incubated with up to 5 Ă— 108 CFU/ml_1 for 19 hours. Recently isolated Pseudoalteromonas strains hCg-6 and hCg-42 from oyster haemolymph were also anaAquaculture Magazine

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research report

lyzed. These strains produced antimicrobial peptide in haemolymph in an in vitro assay. Hemocyte/bacteria mixes did not exhibit any morphological changes, whatever the ratio used and the strain assayed, when examined using flow cytometry. After 3 hours, hemocyte mortality in sterile seawater was quantified at 5.2% (± 0.7). A previous study on Crassostrea virginica hemocyte viability showed that around 3–5% of hemocytes died when incubated in sterile seawater. The hemocyte death observed herein (15% after 19 hour incubation in seawater) is in agreement with the short lifespan of bivalve hemocytes described previously. Moreover, after a 19-hour-long incubation of hemocyte in the presence of hCg strains, flow cytometry analyses revealed that (1) no additional hemocyte mortality was detected with strains hCg-6 and hCg-42, suggesting that these strains have no opportunistic behavior, whatever the hemocyte/bacteria ratio used; and (2) a significant reduction of hemocyte mortality with strains hCg- 23, -51 and -108 (Table 3). Interestingly, hemocyte mortality was significantly decreased in the presence of strain hCg-51 in a concentration-dependent manner. No known similar results showing a dose-dependent reduction of hemo-

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cyte mortality by bacterial strain or metabolites have been published to date. Future experiments will investigate phagocytic activity, adherence, and nitric oxide synthesis of hemocytes. These preliminary in vitro experiments support the beneficial role of bivalve microbiota in stimulating and/or protecting hemocyte cells. Results suggest that the haemolymphatic microbiota may play a role in host immunity and homeostasis. As a result, haemolymph microbiota may represent a potential source for aquaculture probiotics.

Antibiotic sensitivity Major molluscan pathogens such as Vibrio were shown to harbor a high number of mobile genetic elements, showing their abilities to integrate elements that can increase their capacity to colonize an ecological niche. As antibiotics used in prophylaxis were banned to limit the development of bacterial resistance, antibiotic substitutes such as probiotics should not harbor antibiotic-resistant genes. Therefore, researchers investigated the hCg-strains to ensure their antibiotic sensitivity to the common antibiotic used in aquaculture. No resistance to antibiotics was observed for the five tested strains except for the tetracycline antibiotic (Table 4). The medium used (Marine agar) appears to be unsuitable for tetracycline diffusion due to antibiotic co-precipitation with the salts observed. Nevertheless, the recommended medium for anti-

biotic sensitivity assay (i.e. Mueller– Hinton, AFNOR NF U47-106) was unsuited to hCg strains, as no bacteria grew on it.

Conclusions Some culturable haemolymph-associated bacteria can exhibit (1) potent antibacterial activity against some bacterial pathogens in aquaculture; (2) no significant cytotoxic effect on hemocytes but rather a reduction in hemocyte mortality; and (3) sensitivity to the main antibiotic used in aquaculture. Insofar as such strains may confer a health benefit to the host, they may be considered potential probiotics. A combined strategy using antibacterial screening, hemocyte viability and antibiotic sensitivity may allow researchers to focus on a reduced number of haemolymphatic strains for in vivo experiments. As a result, the haemolymphatic microbiota, to which little attention has been given, represents a potential source for future aquaculture probiotics and may be used to renew the antimicrobial arsenal. The bioactive molecules, as well as the dynamics of haemolymph colonization and the ability of strains to protect bivalves from infection are being investigated. *Original article: Desriac, Florie, Exploring the hologenome concept in marine bivalvia: haemolymph microbiota as a pertinent source of probiotics for aquaculture. Federation of European Microbiological Societies (FEMS) Microbiology Letters. Vol. 350, Issue 1, January 2014.

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Conservation Aquaculture; Restoring the Ancient Alligator Gar

This ancient, endangered species has generated increasing interest By Christopher Green, Allyse Ferrara, Quenton Fontenot, and Roberto Mendoza Alfaro*


lligator gar (Atractosteus spatula) belong to an ancient group of fishes that evolved more than 150 million years ago. These fish are covered in tough ganoid scales and are capable of air breathing with the use of a vascularized gas bladder. Historically, alligator gar were found in the Mississippi River and its tributaries from the lower reaches of the Ohio and Missouri Rivers southward to the Gulf of Mexico including coastal riv14 Âť

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for recreation and conservation in recent years. This has promoted restocking programs both in the USA and Mexico in an attempt to restore alligator gar populations in both countries. ers from Florida to Veracruz. This species requires flooded vegetation such as marsh or newly inundated floodplain habitats for spawning. Recent channelization of rivers and streams has negatively impacted inland and riverine populations. The alligator gar is a large, longlived species with a maximum age of approximately 100 years. Males reach sexual maturity between 2-8 years of age and females between 2-12 years of age, depending on latitude and

habitat type. Due to habitat loss and the relatively old age at sexual maturity, fisheries managers in many states are concerned about the future sustainability of populations of this ancient fish. Habitat modification and loss (from channelization of waterways and dewatering of floodplain habitats) and, in some cases, overfishing have resulted in the decline of inland and coastal populations of alligator gar. The US Fish and Wildlife Service

Currently the only US state without harvest regulations for A. spatula is Louisiana, where the majority of commercial and recreational harvest occurs in the coastal region.

Hatchery produced juvenile alligator gar waiting for their next meal.

(USFWS) lists A. spatula as an interjurisdictional “Focal Species” and alligator gar are listed as “imperiled”, “vulnerable”, “critically imperiled”, or “extirpated” by most state natural resource agencies within the species’ historic range. In Mexico, the National Fisheries Institute describes alligator gar populations as “deteriorated” due to overfishing, although harvest is not regulated. The popularity of alligator gar as a sportfish for recreational angling has recently increased. Regulations on recreational and commercial harvests are set at the state level, with the exception of federal refuges that may impose additional restrictions. Many states enforce restrictions on bag limits, harvestable length and allowable gear, while other have established seasonal closures.

Restocking programs To restore alligator gar populations in Mexico and the US, restocking programs using hatchery produced fish were developed. Two Mexican aquaculture centers, Tancol near Tampico, Tamaulipas, and Universidad Autónoma de Nuevo León (UANL) in Monterrey, produce alligator gar for research and restocking efforts. In the US, restocking efforts were started by the USFWS and now include federal, state, and university production facilities. In June 1998, the alligator gar production program at the USFWS Private John Allen National Fish Hatchery (NFH) in Tupelo, Mississippi, began as a regional priority to restore alligator gar populations and prevent listing under the Endangered Species Act. Since 1998, the Pvt. John Allen NFH and partners have developed and refined alligator gar collection, transport and culture techniques. Each year wild broodstock are collected from St. Catherine Creek National Wildlife Refuge near Natchez, Mississippi, spawned and returned to the refuge. The Pvt. John Allen NFH annually produces more than 65,000 fry and fingerlings for restoration stocking in Arkansas, Mississippi, Tennessee, Missouri, Kentucky and Illinois. Since 2008, the Alabama Department of Wildlife and Freshwater Fisheries (ADWFF) has produced and stocked approximately 200,000 larval and juvenile alligator gar into the Mobile Delta and Claiborne Lake on the Alabama River. As a result of increased agency interest in alligator gar culture and management and to facilitate the exchange of techniques and data, the International Network for Lepisosteid Fish Research and Management was formed in 2006 and the Alligator Gar Technical Com-

Alligator gar eggs attached to artificial spawning substrate.

mittee of the Southern Division of the American Fisheries Society was formed in 2009. Over the last two decades, Mexican researchers from UANL, in collaboration with colleagues from the US (Nicholls State University) and Cuba (Universidad de la Habana) have examined various aspects of gar biology, focusing on alligator gar, Cuban gar (A. tristoechus) and spotted gar (Lepisosteus oculatus). Topics of study include morphological, histological and molecular studies aimed at distinguishing different phases of development, as well as the nutritional condition of larval stages for the development of artificial feeds beginning with the earliest exogenously feeding stages. Additionally, results of endocrine based studies have been applied to enhance larval develop-

Habitat modification and loss have resulted in the decline of inland and coastal populations of alligator gar.

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Broodfish are harvested in early May for spawning at the LSU AgCenter’s Aquaculture Research Station.

ment and digestive capacity. Cloning of alligator gar growth hormone has opened new avenues to promote growth in the gars. The use of thyroid hormones has improved the reproductive performance of broodstock and the identification of biochemical markers, such as vitellogenin, has allowed for identification of males and females to establish appropriate sex ratios for reproduction and to evaluate hormone administration protocols to induce gonad recrudescence and spawning.

Photos courtesy of Louisiana Sea Grant.

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In Louisiana, the Department of Wildlife and Fisheries, Louisiana State University Agricultural Center, Natchitoches NFH and Nicholls State University have partnered to produce alligator gar from captive and wild broodstock for research and stocking. Based on induced spawning protocols for alligator gar and tropical gar (A. tropicus) developed by colleagues in Mexico and with the USFWS, production of larvae and juveniles was initiated by Nicholls State University in 2007 at a cooperating private aquacul-

ture facility. Between December 2009 and January 2010, tagged alligator gar were stocked along with largemouth bass (Micropterus salmoides), spotted gar, and bullhead (Ameiurus spp.) to serve as biological controls for escaped tilapia (Oreochromis spp.) remaining in a drainage canal in Port Sulfur, Louisiana after an extensive eradication program led by the Louisiana Department of Wildlife and Fisheries. Subsequent recapture of these tagged alligator gar allowed for analyses of diet and growth within this canal system.

In late 2009, captive broodstock were transferred to the LSU Agricultural Center’s Aquaculture Research Station. Induced spawning of alligator gar at the Aquaculture Research Station began in the late spring of 2010 and has remained an annual activity for the past 4 years. Adults are maintained throughout the year in 0.25 ha ponds and are fed a combination of floating pellets (56 % protein) and Gulf menhaden (Brevoortia patronus). In early May broodfish are removed from ponds, weighed, administered

Recent studies on larval alligator gar have examined salinity tolerance, the influence of salinity on larval growth, and larval/juvenile feeding protocols. an intermuscular dose of LHRHa, and placed in groups of three to four in 3.5 m diameter pools containing spawning substrate. Spawning usually occurs within 36 hours. After hatching the larvae use a unique anterior

suctorial disk to attach to substrates such as vegetation or the walls of rearing tanks. Alligator gar larvae have relatively large yolk reserves and do not begin to feed exogenously until three to five days post hatch.

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Collaborative work in Louisiana has used coastal alligator gar populations for both field and lab based studies. Field collections of sexually mature individuals have provided information on age and growth, reproductive investment, seasonal hormone concentrations, and population structure. Recent studies on larval alligator gar have examined salinity tolerance, the influence of salinity on larval growth, and larval/juvenile feeding protocols. More than 300 individuals produced by these efforts were tagged with Passive Integrated Transponder tags and released at Rockefeller Wildlife Refuge in Grand Chenier, Louisiana for future mark/ recapture studies. This collaborative effort will generate critical data for use in reintroduction efforts in areas where alligator gar have been extirpated or where populations have declined and are in need of supplemental stocking. Offspring produced from alligator gar from coastal Louisiana populations have provided research animals for other alligator gar researchers that have previously only worked with inland populations. Recently, larvae and juveniles were produced for collaborators in Louisiana, Arkansas, and Mississippi for studies comparing coastal and inland populations. Over the past few decades, management and conservation interest in alligator gar has grown and has resulted in the passage of harvest regulations or declarations of extirpation (or possible extirpation) in all US states in the species’ historical range with the exception of Louisiana. Current research on this species spans a variety of disciplines with aquaculture playing an important role in restoration efforts of this ancient fish. *For more information on these studies, contact the authors: Christopher Green: Quenton Fontenot: quenton.fontenot@nicholls.ed Allyse Ferrara: Roberto Mendoza Alfaro:

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Brazilian Aquaculture; a Seafood Industry Giant in the Making

Brazil has all the potential to become the next seafood super power. However, its seafood industry still has to overcome significant barriers to realize it.

By Gorjan Nikolik*


lobal seafood is undergoing a period of growth based on increasing demand and a constrained wild catch supply. In 2010, global fisheries and aquaculture supplied the world with around 168 million tons of seafood, of which 143 million tons were destined for human consumption. This volume represented 24% of all globally consumed animal protein. While global demand has increased steadily, fisheries have remained relatively flat at around 90 million tons since 2006 and are set to hover around current levels over the coming years (Fig. 1). The additional production required will need to be met by the aquaculture industry. However, current leading producers such as China, India, Thailand, Vietnam and Norway have relatively limited ability to expand due to constrained resources. Brazil, on the other hand, has all the ingredients necessary to play a key role and fulfill the expected supply. 20 »

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Brazil’s exclusive economic zone —sovereign territorial waters—is one of the twelve largest water areas in the world (3.5 million km2). It also has a coastline of 8,500 km, stretching across a range of tropical and subtropical climates ideal for aquaculture similar to that of South East Asia and China, which currently account for over 80% of the global production. Brazil also possesses 12% of the planet’s available freshwater reserves. Moreover, Brazil’s current vast grain production along with its still large potential for further growth provide the country with another advantage in production of species that consume a vegetarian diet as feed costs account for around 60% of the total cost of fish production.

tons originating from aquaculture. Although aquaculture production remains low, it has grown rapidly in recent years in the wake of the uncertainty about quality and quantity of the final product obtained through wild capture. Of the total aquaculture output in 2010, finfish species made up 81%, followed by shrimp production (16%), and the remaining part coming from mollusks and frogs. 80% of production is undertaken in fresh water. From a global standpoint, Brazil’s seafood production (wild and farmed) is falling behind countries such as India, Vietnam, Indonesia and China (Fig. 2).

Tilapia, shrimp and tambaqui Although there are currently around 40 different species being farmed in Domestic aquaculture industry Brazil, tilapia, shrimp and tambaqui Despite Brazil’s enormous potential, are the most important ones by far. its growth is still slow. In 2010, its The three combined accounted for total seafood production was at 1.26 nearly 60% of the total output in million tons, with only 479 thousand 2010.

Shrimp farming began in Brazil during the 1980s, but it was only after 1995, with the introduction of Litopenaeus vannamei, that the industry experienced a period of rapid development. Between 1997 and 2003, production grew from 3.6 thousand tons to 90 thousand tons at which point Brazil had become one of the leading shrimp producing regions. Yields increased from 1,050 to 6,084 kg / ha / year in six years. The currency devaluation in this period, which increased the attractiveness of exports, also promoted the advancement of shrimp farming. However, by 2003, the shrimp industry was hit hard by the outbreak of the Infectious Myonecrosis Virus (IMNV). This, coupled with an antidumping action imposed by the Southern Shrimp Alliance (SSA) in the U.S. and the appreciation of the Brazilian Real, resulted in a sharp decline in total output to 63 thousand tons in 2005. Since then, production has slightly recovered, stimulated by the rise in domestic demand. Brazil’s shrimp farmers are currently dedicated to the internal market only. Tilapia farming has posted one of the fastest growth rates among the aquaculture sector in Brazil and in the world. According to the Brazilian

Ministry of Fisheries and Aquaculture, while total aquaculture production has grown by a compounded rate of 8% per year, tilapia output has risen at an annual rate of 17% during the past four years. In 2010, Brazil’s tilapia production amounted to 155 thousand tons, placing the country as the 6th largest tilapia producer in the world. Tilapia consumption is growing in markets such as Asia, South America and Egypt as well as in western markets such as the U.S., which is its leading importer. In the U.S., tilapia imports have grown at more than 20% per year for the last decade and it has become the 4th most popular

species only behind shrimp, tuna and salmon. On the frozen side, China is the dominant exporter of tilapia fillets due to a combination of low production and processing costs. At the moment, China’s position is unchallenged, but in 2011 the first signs of weakness appeared in the Chinese tilapia industry as weather problems affected China’s ability to rapidly expand production and exports. Although exports recovered strongly in 2012, the Chinese tilapia industry was not profitable. This may create opportunities for Brazil to become an important frozen fillet supplier.

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The expansion of the tambaqui species (Colossoma macropomum) has caught Brazil’s attention. Tambaqui is an indigenous fish that has become increasingly popular among consumers given its low fat content and its considerably attractive flavor. Besides being largely available in Brazilian supermarkets, it has been exported to European countries such as Portugal and France. In 2010, Brazil produced 54 thousand tons of tambaqui, an increase of 17% over the year before. Apart from these species, there are others that may have their position strengthened in years to come. This is the case for pirarucu (Arapaima gigas), which is originally from the Amazon area and whose carcass yield can be more than 50%. Another example is the beijupirá (Rachycentron canadum),

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which is highly valued in the international market. Based on conservative assumptions, in which the rate of growth over the next ten years would be equal to half the rate of the past five years, Brazil’s aquaculture industry could reach a production level of 1 million tons by 2022 (Fig. 3).

Fragmentation of Brazilian seafood industry The Brazilian seafood industry can be divided into two different types of players: primary producers and processing companies, with the former acting either independently or vertically integrated. However, regardless of the type of player, the aquaculture market is very fragmented and is composed of small to mid-sized players.

Although availability of information on the processing side is scarce, the size of companies involved can be seen by reviewing data compiled by the Brazilian Development Bank BNDES. It indicates there are 661 seafood processing companies in Brazil, of which only 7 can be considered large scale enterprises. The two leading processors are mostly focused on canned seafood (sardine and tuna) and combined, account for approximately 85% of the canned market in Brazil. Some vertically integrated companies have their roots in the processing link of the chain, but they are also setting their sights on aquaculture production. Others were created mainly to target their own production and import seafood for distribution in Brazil. The ‘on farm’ segment of the industry is quite fragmented. Data collected from the Agricultural Census carried out in 2006 suggest that there were around 156 thousand aquaculture farms in Brazil, of which, 22% were concentrated on tilapia production.

Seafood consumption in Brazil With its 193 million people—the 5th largest population in the world— Brazil is a traditional consumer of animal protein, accounting for 14% and 12% of the total worldwide beef and poultry consumption, respectively. When it comes to seafood, domestic demand in 2010 amounted to a ‘mere’ 1.8 million tons or 1.2% of global consumption. Per capita consumption is still significantly low (9.4 kg in 2010) compared to the world average (around 18 kg). Nonetheless, seafood consumption is one of the fastest growing food segments in Brazil, posting a compounded rate of growth of 9% over the past six years, outperforming other animal proteins (Fig. 4). Demand has been largely driven by higher income levels and the strengthening of the Brazilian real, which has made imports more attractive. Additionally, the search for healthier food options

has opened Brazilian consumers’ eyes towards new cuisines. Another factor has been the increased availability and variety of alternatives at the retail level. Between 2009 and 2011 the volume of seafood sold through the retail channel grew by 33%, jumping from 1.2 to 1.6 million tons. Sardines are a cheap fish, which is mainly marketed in a canned form. Brazilian consumption of sardines reached 110 thousand tons in 2011. Dried cod is a fish traditionally consumed during the Easter and Christmas periods and cod imports have increased by 40% since 2005, reaching 43.4 thousand tons in 2011. Salmon consumption had an unexpected boost in 2008 and 2009 due to the infectious salmon anemia (ISA) outbreak in Chile. Chilean industry had to prematurely harvest nearly its entire Atlantic salmon biomass. These fish, although safe to eat, were too small to be sold as fillets in the U.S. and Europe so were instead sold as whole fish on the Brazilian market far below cost of production. This served to promote the fish to millions of new consumers. Currently, spurred by low salmon prices, Brazilian demand is set to reach a new record. Chilean salmon exports to Brazil for the first six months of 2012 increased by 91% to a total of 31 thousand tons. Tilapia is widely appreciated due to its flavor and nutritional value combined with changes in the way it has been marketed to consumers. This includes a shift from selling the whole fish to selling fillets. Demand has been fuelled by the increase in other meat prices, which have given tilapia a comparatively more attractive value. Assuming that all production stays in the internal market, the consumption of tilapia would still only amount to a mere 155 thousand tons or 0.8 kg per capita.

tion of the Brazilian real have paved the way for an acceleration in Brazil’s seafood imports in recent years. Between 2008 and 2011, the volume of imports grew at a compounded annual rate of 14%, reaching 323.8 thousand tons in 2011, and accounting for 18% of the seafood consumption in Brazil. Primary seafood products imported are salmon and cod. These two species together accounted for 25% of the total volume imported in 2011. Moreover, imports of filleted fish from China are gaining momentum, with the country becoming the largest seafood exporter to Brazil (in volume) in 2011, outpacing Norway, Chile and Argentina, whose main export to Brazil is hake fillets (Fig. 5). China dominates the global supply of frozen fillets. In a similar fashion, the Vietnamese Pangasius industry has identified Brazil as a future destination for their fillets, which are increasingly difficult to sell in Europe. In spite of the recent increase in total imports, the Brazilian market is still relatively closed. Imports of shrimp, for instance, have been prohibited since 1999 due to sanitary risks.

Bottlenecks On the regulatory side, one of the weaknesses is the legal framework concerning the use of water for aquaculture. There is considerable bureaucracy to overcome to obtain all of the permits/licenses to start an aquaculture operation. In addition, there’s a lack of biosafety standards for production of the majority of species. Low yields and size heterogeneity also prevent the sector’s flourishing as Brazilian husbandry methods are still quite primitive. This issue could be partially solved if the relationship between the links of the chain were more coordinated (integrated system). Under such an arrangement, Imports processors (integrators) would supRapidly growing domestic demand ply growers with all the necessary together with the limited seafood inputs and therefore have control production and the recent apprecia- of genetics and feeds. Additionally,

Brazil’s intrinsic natural resources make it a potential aquaculture powerhouse.

integrators generally provide technical assistance to farmers in order to enhance animal husbandry so that they can capitalize on the high quality inputs. Another hurdle is the underdeveloped feed industry for the sector, despite the large availability of grains. As there are many species being grown with a wide range of eating habits and living environments— usually on small-scale farms—it is not economically feasible for companies to produce specific rations suitable for each situation on a large scale. The result is a combination of poor quality feed and high prices. The aquaculture industry itself will probably have to lead the research focused on enhancing feed quality, through partnerships with research institutes and feed companies. Infrastructure is another important obstacle. Many areas granted to aquaculture farms are very far from roads, ports, feed blenders, consumption areas, and so on, which poses additional challenges to the operation and, consequently, economic feasibility of such projects. Last but not least, the lack of public information about the sector has likely prevented investors from better assessing the potential of such a market.

Opportunities Despite these challenges, outlook for the Seafood sector in Brazil is quite bright. The country possesses the Aquaculture Magazine

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key factors for becoming an aquaculture powerhouse. On the domestic side, the speed of demand growth for seafood should maintain momentum, driven by rising income levels coupled with changes in consumers’ preference towards food quality and healthier products. Additionally, it’s very likely that the Brazilian government will continue rolling out incentives to encourage consumption. In fact, the government has already been relatively active in this market through the acquisition of seafood to be distributed in public schools. If it is assumed that consumption will grow at 7% for the next four years—similar to the levels seen in past years—, total consumption could jump to 2.6 million tons in 2015. This fast-growing domestic consumption is also likely to promote an increase

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in Brazilian seafood imports as some of the preferred species cannot be grown in Brazil, notably salmon and cod, which require cooler temperatures. Under this scenario, exporters from Norway, Portugal and Chile could also benefit from anticipated demand expansion. Export opportunities could be driven by the growing international demand for seafood, which is expected to grow by 27 million tons by 2030. Additional boosts to Brazilian exports will come from the declining rate of global aquaculture production growth on the back of water constraints and rising feed costs. Within the aquaculture sector in Brazil, tilapia and shrimp segments— whose value chains are far ahead of the others—are the ones who could profit most from this scenario. In white fish, the question is whether Brazil can create an industry which will replicate the success of Pangasius, which is almost exclusively produced in the Mekong Delta in Vietnam, and within less than ten years expanded from a small backyard industry into a professional industry exporting to every large market globally and producing above 1 million tons. However, due to a worsening image with Western consumers and rising feed costs, production from this Vietnamese indus-

try has stagnated for the last three years. This may open opportunities for native species such as tambaqui and pirarucu—with features such as fast growth rate, white color, mild flavor and a vegetarian diet (and thus low feed cost)—to play a role in the global freshwater white fish market and compete with Pangasius. All of these factors combined point to the expectation that the leaders in the global seafood industry will increasingly consider Brazil as the next frontier of seafood, notably aquaculture. This may also entice Brazilian meat giants to venture into the aquaculture space. Brazil’s top four meat producers—with combined revenues of USD 62 billion in 2011— have developed logistics, feed production, unrivalled expertise in animal protein production and a global footprint that could be extended to the aquaculture sector. For Brazilian meat companies, aquaculture can be seen as a source of diversification and an opportunity to generate growth levels far higher than in the meat industry.

Conclusion Brazil has all the ingredients necessary to become a seafood superpower. However, the Brazilian seafood industry still has to overcome some barriers to fulfil its potential. Despite having to overcome such challenges, the outlook for the seafood sector in Brazil is quite appealing. All in all, in spite of all the challenges the Brazilian aquaculture sector will have to cope with over the coming years, the country—led by private and government investments—will enlarge its importance in the global aquaculture scenario.

*Original article: Gorjan Nikolik. Brazilian Aquaculture; A Seafood Industry Giant in the Making. Rabobank Industry Note #362, January 2013.

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research report

Effect of oxidation– reduction potential

on performance of European sea bass in RAS systems With limited land and clean seawater resources, and increasing By Xian Li, Jean-Paul Blancheton, Ying Liu, Sebastien Triplet, and Luigi Michaud*


n response, recirculating aquaculture systems (RAS) or semi-RAS are frequently used instead of flow-through systems, as they offer advantages such as a stable environment in terms of physico-chemical parameters and microbial flora, which provides an effective control or pre-control of diseases and improves the welfare of culture animals and less environmental impact. Many studies have focused on optimizing the RAS environment in order to optimize the living conditions of cultured animals. They have

European sea bass (Dicentrarchus labrax)

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demand for seafood, the expanding aquaculture industry is facing many challenges. studied the impacts of water quality parameters such as pH, temperature, salinity, and dissolved gas in RAS on the biological performance of fish. Seawater is a complex medium with strong interactions among chemical parameters, as pH interacts with the gas balance (mainly CO2), and pH and temperature affect the balance between un-ionized and ionized ammonia. The oxidation-reduction potential (ORP) results from all reactions involving both oxidations and reductions and varies as a function of the standard potential, relative ion

concentration, temperature, and the number of electrons transferred. It is dependent on all oxidants and reducers present in the system. In water, the ORP is strongly related to temperature, pH, salinity, and concentrations of dissolved oxygen and dissolved oxidants such as ozone. Nowadays, ozone is wildly used in aquaculture for disinfection, water treatment, and bacteria control. During ozonation, ozone reacts with several compounds resulting in the formation of ozone-produced oxidants (OPO), also mentioned as total residual oxidants (TRO) including free bromine (HOBr/OBr-) and bromamines (NH2Br, NHBr2), which are more stable than ozone. The toxicity of TRO and particularly of related bromate compounds to aquatic animals at low dosage is focused. However it is also proved that bromate will not be formed when ammonia is present in seawater. To date, few studies have mentioned a direct connection between ORP and biology, although most existing reports describe ORP as an easy tool for monitoring ozonation in aquaculture systems. A study in 2009 reported that ORP of 375–525 mV was required to reach the mean daily ozone concentration necessary to obtain full-flow disinfection in fresh-

water RAS. For southern rock lobster larvae, survival was higher and bacterial contamination was lower when the ORP was between 330 and 500 mV. With moderate ozonation corresponding to an ORP value of 250 mV in a low exchange freshwater RAS, rainbow trout showed improved performance compared to a system without ozonation. However, the influence of ORP modification using ozonation on marine fish physiology in RAS has rarely been studied. In particular little is known about European sea bass which is widely cultured in the Mediterranean Sea. In this study, the impacts of (1) four successive ORP levels induced by ozonation and (2) fish sizes on physiological and hematological parameters of European sea bass (Dicentrarchus labrax) were studied and compared to data from a RAS without ozonation. The goals of this study were to identify the safe range of ORP for sea bass and to evaluate how European sea bass respond to ORP alterations.

Materials and methods Two RAS located at the French Research Institute for Exploration of the Sea (Ifremer, Montpellier, France) have been running for several years. Each consists of three 1 m3 fish tanks, a mechanical filter, UV disinfection, a protein skimmer, a warm-cold exchanger, moving bed biofilters, a degassing unit, and storage and pumping tanks organized in four loops (Fig. 1). In the first one, water flowing out of the fish tank is filtered in a mechanical filter and pumped from the storage tank back to the fish tanks. Three parallel loops connected to the pumping tank were used for the other water treatments (1) biofiltration, (2) ozonation and protein skimming and (3) UV disinfection, a heat exchange, and degassing. The first of the two RAS was equipped with an O3 generator, which converted pure oxygen to ozone. This system was named RAS O3. The O3 generator was conAquaculture Magazine

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research report

trolled by an ORP sensor placed after the biofilters and delivered a maximum of 4 g O3/hour. In the second system, named RAS, air was used as feed gas in the skimmer. Two systems were set up in the same way before ozone injection into RAS O3. pH was controlled by injecting sodium hydroxide into the pumping tank in order to keep the value around 7.2–7.8 in the fish tanks. Temperature was maintained at 21.5 °C. Salinity was between 20-30 ppt. Oxygen concentrations in all fish tanks of both systems were almost similar at a super saturation level between 120140% except it in fish tanks of RAS O3 was 10% higher than RAS in the first two days at the P3 period. The water flow rate to each fish tank was 1 m3/hour-1. The daily water renewal rate was between 1 and 2 m3 of new water per kg feed. The ORP was stabilized at four successive levels: 260–300 mV, 300– 320 mV, 320–350 mV and 300–320 mV in fish tanks during four periods (P1-4) as shown on Table 1. During the P1 period, the ORP level was increased gradually over 4 days to reach ~290 mV in the fish tanks, and this value was maintained for 8 days. During the P2 period, the ORP in the fish tanks was between 300 and 320 mV. During the P3 period, the ORP in the fish tanks was 320–350 mV. Three days after the ORP reached 330 mV, mortality occurred. Two days later, ORP was decreased to the same level as that of the P2 period (320 mV), and it was maintained for 15 days during the P4 period. European sea bass were reared at Ifremer. They were first stored in one big tank for several months. Two months before the trial, they were transferred to the RAS. During this time they were fed at 1.0–1.5% of biomass/day. Before distribution into the tanks, fish were starved for 24 hours and anaesthetized using eugenol (40 mg/ l-1). Three fish sizes were selected as follows: S1: 100 g; S2: 150 g; and S3: 28 »

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200 g. Each size class was distributed into one of the three tanks in each of the two RAS at a stocking density of 20 kg/m–3 (Table 2). During the experiment, fish were fed Ep 3-5 dry pellets at 1.0–1.5% of biomass/day using auto feeders. The ingested feed quantity was calculated from the feed trap. Temperature, salinity, pH, and oxygen concentration in the fish tanks were monitored and recorded daily. Water samples from the fish tanks were collected at 10:00 a.m. twice a week and stored at –20°C after being filtrated on GF/C porous membrane. TAN (total ammonia nitrogen), NO2-N (nitrite-nitrogen) and PO4-P (orthophosphates) were measured. Total suspended solid (TSS) concentration in the fish tanks was determined twice a week after filtration on GF/C porous membrane; data were expressed in the unit of mg/1 l water. Total resident ozone (TRO equal to OPO) in the fish tanks was measured three times a week at the P1, P2, P4 periods while three times a day at the P3 period using the colorimetric N,Ndiethyl-p-phenylenediamine (DPD) method. Its concentration was expressed as mg/l-1 of chlorine. All fish were starved for 24 hours before sampling. At the last day of each period, fish were removed from

the tanks and blood was taken from the caudal vein with syringes within 30 seconds. Immediately, one or two drops of the blood were used for hematological parameter measurements using an I-STAT portable analyzer equipped with CG8+ cartridges. pH, pCO2, pO2, HCO3, total CO2 (TCO2), O2 saturation (sO2%), sodium (Na), potassium (K), ionized calcium (iCa), glucose (Glu), hematocrit (Hct), and hemoglobin (Hb) of the whole blood were measured. The remaining blood was placed in dry heparinized Eppendorf tubes and centrifuged for 15 minutes at 5,000 rpm at 4°C. The upper plasma was collected in the Eppendorf tube and stored at –80°C until analysis. At the end of P1 and P2 period, four fish more from S1 group and one fish more from S2 group were removed to avoid density interference. The concentration of protein in the plasma was determined by spectrophotometer. Based on the reaction of protein with alkaline Cu2+, the plasma was first diluted 2,000 times in a four-step operation to obtain the best test range. Tests were performed, and run in duplicate. Since the P3 period, some fish in bad status were lying on the bottom. The fish sampled in RAS O3 at the P3 and P4 periods were only swimming.

All results were expressed as mean ± S.D. All statistical analyses were performed using SPSS 16.0. Data were first tested for homogeneity using Levene’s F-test. The percent data were analyzed after arcsine transformation. The differences in water quality parameters between RAS O3 and RAS at the P1 and P2 periods were evaluated using paired t-tests. The differences in hematological parameters and plasma protein were compared using a two-way ANOVA (fish size, ORP and fish size*ORP). Differences were considered statistically significant at p <0.05.

Results There was no significant difference on all water parameter concentrations between the RAS and RAS O3 groups during the P1 and P2 periods (p > 0.05) (Table 3). During these periods, the TSS concentration in the RAS O3 fish tanks was slightly higher than that in the RAS tanks, but the difference was not significant (p > 0.05). The TSS

The oxidation-reduction potential (ORP) results from all reactions involving both oxidations and reductions and varies as a function of the standard potential, relative ion concentration, temperature, and the number of electrons transferred. and TAN concentrations of the RAS O3 group peaked during the P2 period and then decreased during the P3 and P4 periods. There were no dead fish in RAS group during P1-4 periods. Although the ORP was set back to 300–320 mV during the P4 period, mortality during P4 was two times higher than that during P3 (Fig. 2). The mortality of medium size fish (S2) was slightly higher than that of the two other sizes, whereas mortality of the largestsized fish (S3) was the lowest, especially during the P4 period. At the end of the P1 period, blood O2 concentration, measured as PO2

and sO2% , was first significantly influenced by the increased ORP (p < 0.05). At the same time, Hct and Hb were lower in both the S1 and S2 groups of RAS O3 and significantly affected by ORP (p < 0.05). Besides ORP had a significant effect on iCa concentration. No effects of fish size and ORP/ fish size interaction on related parameters were recorded (p > 0.05) (Table 4). At the end of the P2 period, fish in RAS O3 had higher blood oxygen, lower blood CO2, lower Hct and Hb compared with same size in RAS. Besides, fish in RAS O3 showed a higher blood Na and Glu. Two-way ANOVA analysis revealed statistically significant effects of ORP (p < 0.05) on most hematological parameters, including pH, pCO2, pO2, HCO3, tCO2, sO2, K, Glu, Hct and Hb. Fish size had significant effects (p < 0.05) on pH, pO2, HCO3, sO2, K and Glu. In addition, fish size and ORP interaction had significant impact on pH, pO2, tCO2, sO2, K and Glu concentrations. One day after ORP reached around 320–350 mV at the P3 period, fish in RAS O3 began to show an appetite depression. Three days later, mortality occurred. During the P3 period, fish in RAS O3 exhibited a tired behavior and responded slowly to stimulation. They could be divided into two populations: fish swimming in the upper water column and fish lying on the bottom of the tank. Once fish were lying down, they died 1–2 days later. Thus, only upper swimming ones were sampled for blood parameters including hematological parameters and plasma protein. Aquaculture Magazine

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Compared with the RAS group, fish in the RAS O3 S group continued to show a higher O2, lower CO2, Hct and Hb concentrations and had a higher Glu concentration compared with fish of the same size in RAS. Two way ANOVA revealed that ORP significantly (p < 0.05) impacted most hematological parameters, including pH, pCO2, pO2, HCO3, tCO2, sO2, K, Glu, Hct and Hb. Fish size had significant effects (p < 0.05) on pCO2, Na, Glu and Hb. Fish size and ORP interaction had significant effects (p < 0.05) on pH, Glu, Hb, etc. At the end of the P4 period, all groups in RAS O3 had lower PCO2, HCO3, and TCO2 and higher PO2 and SO2 than the groups in RAS. The increase in Glu concentration in RAS O3 was higher with increasing fish size, and the level was higher in the S2 and S3 fish compared with the fish of the same size in RAS. Hb of S2 and S3 fish and Hct of S2 fish in RAS O3 were lower than those in RAS. Two-way ANOVA revealed that ORP had significant impacts on all hematological parameters except Na and iCa concentrations (p<0.05). Meanwhile fish size notably influenced pO2, HCO3, tCO2, sO2%, Na, Glu, Hb and Hct. Fish size and ORP interactions significantly impacted pH, pCO2, pO2, Glu, Hct and Hb. At the end of P3 period, RAS O3 had a lower plasma protein concentration compared with RAS. The two-way ANOVA analysis showed that ORP significantly impacted (p<0.05) plasma protein concentrations of fish in RAS O3 since the P2 period. At the end of P3 period, the significant influence of ORP (p<0.05) on the protein concentration continued. At the same time, fish size also had a significant influence (p<0.05) on the plasma protein concentration. While at the P4 period, no significant impact (p > 0.05) of fish size and ORP on the plasma protein was found. 30 »

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Discussion It is noticeable that ORP levels and TRO concentrations measured in this study were not consistent with those reported from previous studies, likely due to the use of different ORP probes and their locations. In the current study, the ORP level measured in fish tanks of the RAS, using ODEON probes calibrated once a week on average was 250–270 mV. Thus, it is not easy to compare the ORP level among different RAS because of differences in seawater parameters, aquaculture operations, and probes. Moreover, it would take 2 hours to obtain the ORP equilibrium value when salinity is 30 ppt. Overall, ORP measurement remains a challenging issue. Ozone effectively oxidizes ammonia, and nitrite degrades yellow substances and modifies the biochemical oxygen demand and organic carbon concentration in freshwater or marine RAS. For instance, in an ozonat-

ed marine Atlantic halibut RAS, when ORP reached 320–340 mV in the biofilters, it resulted in a 15% reduction of total organic carbon and a reduction in nitrite, color, and suspended solids compared to the control RAS with an ORP of ~220 mV. No significant benefit of ozonation on ammonia or nitrite reduction was detected in the current study. This was likely because the fish biomass was far from the carrying capacity of the biofilters. Water in both systems showed a suitable quality for sea bass. However, there was an increase in TSS in RAS O3 during the P3 period, and this was attributed to accumulation of uneaten feed in the system. TSS in RAS O3 during the P4 period decreased, likely because fish exhibited decreased appetite. Parallel experiments, carried out on the microbial flora of both the rearing water and the biofilter media, revealed a moderate impact of ORP on bacterial abundance, activity and diversity.

In this study, the glucose concentration was significantly influenced by the oxidation-reduction potential (ORP) levels.

Once ORP exceeded 320 mV during the P3 period, fish appetite decreased. Three days later, first mortality occurred. After the ORP was decreased to 300–320 mV during the P4 period, mortality continued. Most previous studies related to ozonation toxicity were carried out on fresh water species or focused on the acute response. Rarely data are available for European sea bass. Some researchers suggest concentrations of ≤ 0.06 mg/l-1 as acceptable OPO levels for turbot juveniles. For white perch, gill cell damage was observed at an OPO concentration of 0.05 mg/l-1 for 96 hours, and LC-50 (lethal concentration leading to 50% death) for adult white perch was around 0.2 mg/l–1. For Paralichthys olivaceus, 48 hours LC50 was around 0.13 mg/l–1. Therefore, mortality, which occurred two days after ORP reached 320-350 mV in the RAS O3 fish tanks at the P3 period, is to be attributed to the ORP and not to TRO concentration. In addition, mortality continued at the P4 period, even when the ORP level fell to the same level as it was at the P2 period. It seems that the damage to fish health caused by too high ORP levels is not easy to be recovered. In conclusion, even a short-term too high ORP in fish tanks should be avoided in aquaculture systems. Hematological parameters are widely used to evaluate toxic and chemical stress and to determine the health status of fish. The alterations of iCa and K that were induced by ORP indicated an adjustment of metabolism in blood cells.

Hb is the protein in red blood cells that delivers oxygen to the organs, and Hct describes the percent of red blood cells. Hb and Hct were significantly affected by ORP levels over the P1, P2, P3 and P4 period. A decreased Hb and Hct and a blood gas balance modification (higher blood O2 and lower CO2) was measured in the RAS O3 sea bass compared with same size fish in the RAS. A two-way ANOVA analysis revealed that the ORP level significantly affected the gas balance in the blood. At the end of the P1 period, sO2% was significantly influenced by ORP. During P2 period it affected significantly most blood gas parameters including pCO2, pO2, HCO3, tCO2, and sO2%. It seems that ORP above 300320 mV would negatively influence the sea bass hematological parameters. There is available information on the relationship between ORP levels and fish physiology. It seems that fish species react differently to ozonation. Prior researchers reported the increased red blood cell and Hct concentrations in turbot juveniles exposed to ozonated seawater, should be regarded as adaptation to TRO rather than to toxicity. For rainbow trout in an ozonated RAS, Hb

and Hct were slightly lower than in fish in a RAS without ozone, but the difference was not significant. Others suggested that, the decrease of Hct and Hb in the red blood cells of fish exposed to ozone, corresponded to liquid peroxidation and hemolysis of the cell membrane. In this study, TRO remained lower than 0.02 mg/ l-1 at the P1, P2 and P4 period, and the concentration of 0.03-0.05 measured at the P3 period was below the toxic dose. Therefore the decreased Hb and Hct observed in this experiment corresponded likely to the long-term adaption of the fish to the modified ORP and not to the toxicity of TRO on red blood cells. Since the oxygen concentration of fish tanks in RAS and RAS O3 were similar, the influence of ORP on the gas balance and the function of related blood cells in the fish needs to be investigated further. Acid–base regulation in fish is complex and involves a series of reactions for regulating HCO3- and H+ concentrations in the blood. In this study, blood pH was also significantly affected by the ORP levels at the end of P2, P3 and P4 periods, and corresponded to a gas balance modification in the blood.

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bass recovered from a hydrogen peroxide exposure was not observed in this experiment.

Most of living organism’s energy comes from carbohydrate transformation, which increases to meet energy demand during stress situations. It is well acknowledged that blood glucose levels are closely correlated to the level of stress of fish. In this study, the glucose concentration was significantly influenced by the ORP levels since the P2 period (ORP between 300-320 mV). Glu was higher in RAS O3 than in the same size fish in RAS. During the entire experimental period, the plasma protein ranged be-

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Conclusion Results showed that several hematological parameters were altered by increased ORP levels. Blood glucose and plasma protein concentration alterations indicated that ORP above 300-320 started to stress sea bass. Short term exposure to ORP levels around 320-350 induced mortality. Therefore it is strongly recommended that that the ORP level, which is increased by the use of strong oxidants as ozone, should be maintained tween 55 and 70 mg/ml–1, which is in below 320 mV for European sea bass accordance with data reported from rearing in RAS. Further studies are necessary to previous studies. At the end of P2 and P3 periods, protein concentration identify the best ORP level for Eurowas significantly influenced by ORP, pean sea bass grow out, and to invesindicating that ORP around 300-320 tigate how ORP alters the physiologimV started to stress sea bass. During cal fish parameters. P3 period when ORP rose to 320–350 mV in the fish tanks, fish appetite was depressed and mortality occurred. As a consequence, protein in plasma de*Original article: Blanchelot, Jean-Paul, Effect of oxidation–reduction potential on performance of creased due to the lack of nutrients European sea bass (Dicentrarchus labrax) in recirculating aquaculture systems. Aquaculture International. and impaired health. The increase of Springer. January, 2014. plasma protein measured when sea

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Toxic Effects of Antiparasitic Pesticides Used by Salmon Industry in Monocorophium insidiosum

The use of antiparasitic pesticides has been widely required by By Felipe Tucca, Mauricio DíazJaramillo, Gabriel Cruz, Jeannette Silva, Enrique Bay-Schmith, Gustavo Chiang, and Ricardo Barra*


uring the last decade, salmon industry has shown remarkable growth within aquaculture. However, in recent years, susceptibility of salmon farms to ectoparasitic disease outbreaks has resulted in significant economic losses due to decreases in production. Thus, the industry has developed a wide range of antiparasitic pesticides (APs) such as emamectin benzoate (EB), avermectin and synthetic pyrethroids, cypermethrin (CP), and deltamethrin (DE). These compounds present low solubility in water and high octanol–water partitioning coefficient such that the probability of being absorbed by suspended organic matter and being bioavailable in sediment is high. Therefore, potential exposure and bioavailability to sediment-associated organisms, such as benthic invertebrates, may lead to lethal effects. Likewise, the low capacity of invertebrates to detoxify the quick action of compounds, such as pyrethroids on nerve cells, allows to infer the selective toxicity to non-target organisms, such as benthic crustaceans. 34 »

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the salmon industry, but the emission of chemicals into seawater has produced uncertainty about their potential effects in non-target organisms. Marine amphipods have been successfully used as ecotoxicological test organisms in sediment due to their sensitivity to a wide variety of contaminants, abundance, easy collection and laboratory manipulation,

and discrete motility in addition to being an important ecological component within the benthic community. Monocorophium insidiosum is a tubeforming amphipod with an extensive distribution in coasts of Europe and

Monocorophium insidiosum . Photo courtesy of: jsp?GRP=Crustaceans-Amphipods

east coasts of the Pacific Ocean. It inhabits estuarine and brackish waters from infra-littoral zones with a basic supply of suspended particles, micro-fauna, diatoms, phytoplankton, and zooplankton. Ecotoxicological tests with these amphipods have shown effective results in tests with contaminated sediments and low-sensitivity external factors, so their responses have been considered as a good toxicity indicator. Bioassays combined with appropriate biomarkers on marine organisms, can result in a satisfactory method for monitoring AP. Biomarkers allow for assessing responses at the biochemical level by providing an early warning of the potential effects of a chemical product on living organisms. The antioxidant defense system plays an important role in homeostasis as well as in the detoxification of chemicals by preventing oxidative cell damage caused by reactive oxygen species (ROS), such as superoxide free radicals (O2•-), hydrogen peroxide (H2O2), and hydroxyl radical (OH•). During the toxicity pathway many pesticides produce free radicals, which induce lipid peroxidation or alter the antioxidant capacity in aquatic organisms. Oxidative stress responses, such as the activity of glutathione S-transferase enzymes (GST) and thiobarbituric acid reactive substances (TBARS), have been used as biomarkers in marine crustaceans. Lipid peroxidation of unsaturated fatty acids in phospholipids triggers further damaging effect

on cell membranes, so assessments of biomarkers, such as TBARS, have been considered good indicators of membrane peroxidation. The aim of this study was to assess the sensitivity of the marine amphipod M. insidiosum to AP through ecotoxicological tests in sediment by measuring acute (lethal concentration [50 % of the population [LC50-10d]) and sub-lethal (GST and TBARS) end points at different exposure times (2 and 10 days).

Materials and Methods Commercial standards of EB, CP, and DE were purchased for toxicological testing. Analytical standards were kept at room temperature for later use. Amphipods and native sediment were collected in the intertidal zone of Cocholgüe Beach, Bay of Concepcion, Chile. M. insidiosum was collected over 4 cm of the surface sediment with a sieve size of 500 µm, transferred to containers with seawater and fresh native sediment, stored, and transported to the laboratory, where amphipods were carefully transferred to trays with fresh seawater and kept under continuous aeration until their use in toxicity tests. Collected sediment was used as substrate in toxicity testing: It was first sieved using a mesh size of 1,000 µm, repeatedly washed to eliminate macro-fauna and larger organic particles and finally dried for 24 hours at 140ºC. The fine suspended particles (FSPs) washed out by the cleaning process were left to settle and

suctioned with a pipette to be added back for sediment structure reconstitution at sediment-spiking time. Each standard solution corresponding to AP was diluted in acetone organic solvent due to the feasible dissolution of its active ingredient. Solvent control contained the maximum volume of acetone in the standard solution used for assessing pesticides. Containers with 20 g of sediment were prepared and independently spiked with AP standard. Containers were mixed to achieve homogeneity and volatilization of the solvent. Treatment concentrations are reported as µg a.i./ kg-1 of dry sediment (µg/kg-1). Subsequently, 150 ml of oxygen-saturated fresh seawater, 3 ml of FSP, and microalgae Dunaliella sp. [2 ml (1.5 X 105 cell/ml-1)] were added. FSP were provided as structural substrate for amphipod tube-building and microalgae as suspended food source. Amphipods were not further fed nor received continuous aeration during the bioassay. For each test, a number of 10–12 individuals with sizes 3 - 4 mm were incorporated. Coarse and fine fractions in sediment were determined by a digital decanting tube and microparticle analyzer, respectively. Total organic matter content was determined by incinerating the sample in an oven for 4 hours at 550ºC. To assess lethality in amphipods, five nominal concentrations were considered, which allowed for determining LC50 values in amphipods after 10 days of exposure. Previously, a preliminary test was performed

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Lethal toxicity calculations (LC50– ) were analyzed using the PROBIT regression model and trimmed Spearman–Karber. The latter analysis was used when the data showed no normal distribution and nonparametric analysis was required. For biochemical responses, significant differences were evaluated through analysis of variance among treatments using Newman–Keuls test (p\0.05). Differences between solvent control and treatments were considered. Previously, the assumption of normality and homogeneity of data were analyzed. 10d

through a wide range of concentrations to determine the definitive test (Table 1). Dead and immobile amphipods were registered. For sub lethal tests, biochemical responses were made from the results obtained in acute tests, in which the LC in 1% of the species tested was defined. Each test consisted of three different concentrations (five replications each) under the lethality threshold through a dilution factor of 0.5 (EB = 25, 50, and 100 µg/ kg-1; CP= 2, 4, and 8 µg/kg-1; and DE = 0.025, 0.05, and 0.1 µg/kg-1). Exposure times considered for each test were initial time (t0), 2 days (t2), and 10 days (t10). Amphipods (n = 10–12) were pooled to obtain a reasonable amount of tissue for the biochemical analyses. GST enzyme activity was determined according to a previously established protocol, and proteins were analyzed. Briefly, tissue was weighed and homogenized (1:10 w/v) in cold sucrose buffer (20 mm Tris–base, 1 mm ethylene diamine tetraacetic acid, 1 mm DL-dithiothreitol, 500 mm sucrose, and 150 mm KCl) with pH adjusted to 7.6. As a protease inhibitor, phenylmethylsulfonylfluoride (PMSF) solution was used in the ratio 5 ml of sucrose buffer to 5 µl PMSF. Homogenates were centrifuged at 10,000 rpm for 30 min (4ºC), and the supernatant was collected and stored at -80ºC for later use. GST activity (nmol min-1/ mg-1 protein) was measured through the combination of 1 mm of gluta36 »

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thione and 1 mm 1-chloro-2,4-dinitrobenzene at 340 nm. For TBARS analysis, amphipod pools were homogenized in 1.15 % KCl solution, which contained 35 µm of butylated hydroxytoluene in the ratio of 0.01 g of tissue to 90 µl of homogenization solution. Homogenates were stored at -80ºC for later analysis. Measurements were performed by fluorometric analysis (λexcitation = 515 nm and λemission = 553 nm) for determining TBARS using tetramethoxypropane as standard.

Results For acute tests, less than 10 % mortality was observed in controls with a range between 4 and 8 % lethality for the solvent control (fig. 1). AP testing showed that EB had the highest LC50 at a concentration of 890 µg/ kg-1, contrary to what happened with CP and DE pyrethroid compounds, in which there was a greater lethality in tested amphipods with 57 µg/kg-1

Monocorophium insidiosum. Photo courtesy of:

and 7.8 µg/kg-1, respectively (Table 2). Considering a threshold of lethality in 1% of the test organisms, it was possible to define the concentrations for sub-lethal responses in amphipods. Biochemical responses were observed in M. insidiosum after 2 days of exposure to pesticides. No significant differences were found between controls for GST activity in each of the tests with AP. However, a significant difference was observed between controls for TBARS with the CP pesticide with a greater level detected in the initial control (p\0.05). For biochemical analysis between the solvent control and treatments, a significant induction can be distinguished in GST activity for 100 µg of EB/kg of sediment (p\0.05). Likewise, a significant increase of TBARS was observed at 50 µg/kg-1 in the amphipods tested (p\0.05). Moreover, tests with CP showed significant differences between the solvent control and GST activity at 8

µg/kg-1 (p\0.05), with a progressive increase at greater concentrations. Similarly, a TBARS increase was observed in amphipods after 2 days of exposure to CP (p\0.05). In contrast, DE registered a slight increase in GST activity at the lowest exposure concentration (0.025 µg/kg-1) compared with other treatments, but it showed no significant differences with the solvent control. Equivalently, TBARS showed no differences between treatments and control. Significant differences were observed between controls and treatments for GST activity and TBARS after 10 days of exposure to AP (p\0.05). Amphipods exposed to EB exhibited a significant induction of GST at 100 µg/kg-1 compared with the solvent control (p\0.05). Similarly, a significant increase in TBARS was reported (p\0.05). In contrast, tests with CP and DE pyrethroid registered no differences for GST and TBARS activity with respect to the solvent control.

Discussion The sensitivity of M. insidiosum to AP varies according to the active element to which it is exposed, with pyrethroid compounds, such as CP and DE, having more effects on it than EB avermectin. Table 3 lists a summary of sediment ecotoxicological studies for different species of marine benthic invertebrates exposed to pesticides. Toxicity data for EB organic compound (LC50 = 890 µg/kg-1) obtained in this study suggests an LC50 greater than that reported in the literature for other marine amphipods. In contrast, an LC50 of 57 µg/kg-1 was reported for CP, which is similar to the results of other studies with the amphipod Corophium volutator, in which an LC50 of 42 µg/kg-1 was found. Tests performed in other crustaceans, such as the shrimp Palaemonetes pugio, have shown greater sensitivity. Through acute tests performed in amphipod C. volutator with antiparasitic commercial products, prior researches showed that

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CP, as an a.i. in its formulation, is 11 times more toxic than those observed in this study (Table 2). The difference obtained in results of this study for CP and EB compared with other toxicological studies with amphipods could be explained due to uneven loads of organic matter in the sediment or to poor homogenization of pesticides in this substrate, which would prevent proper distribution and bioavailability for amphipods. Greater sensitivity was observed with the DE pyrethroid compound on the amphipods tested after 10 days, in which an LC50 of 7.8 µg/kg-1 was reported. Several studies have reported acute toxicity of DE on marine invertebrates in water showing lethal levels in the order of ng/l-1. However, no information could be found on sediment toxicological tests with which to compare the results obtained in this study. Meanwhile, the high mortality of amphipods against DE can be explained by the significant toxic selectivity of this pesticide on invertebrates, mainly by the rapid and effective action exerted on the central nervous system and other tissues. In this study, the role played by GST enzyme activity in the detoxifying process of M. insidiosum shows significant increases in the antioxidant defense against EB pesticide during 2 and 10 days of exposure. TBARS increases were observed even during GST enzyme action. This increase in lipid peroxidation on the tested organisms could be due to a failed antioxidant defense by GST enzymes when exposed to 100 µg of EB/kg of

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sediment. In contrast, the prolonged antioxidant response in amphipods can be due to properties such as the high persistency of EB in sediment (175 days) and high adsorption capacity to the particulate material, so that its presence after 10 days could manifest the measured behavior. Few studies of oxidative stress in invertebrates have been reported for the EB pesticide. However, significant inductions in GST activity have been reported in marine organisms, such as Salmo salar. Pyrethroid compounds are a group of pesticides with a high capacity to disrupt the antioxidant capacity, producing free radicals and lipid peroxidation. Researchers have indicated that GST enzymes may act as a suitable indicator of exposure to CP within an enzyme detoxification system. Increases in GST enzyme activity and effects on lipids at 8 µg of CP/kg of sediment have been observed in this study after the amphipods were exposed for 2 days. However, measurements at 10 days showed no significant responses. Results may indicate that short-term exposures can provide greater reliability of the data obtained. According to the results obtained with DE, no significant detoxifying activity was observed by M. insidiosum against tested nominal concentrations; however, a slight increase in GST at 0.025 µg/kg-1 was observed, possibly due to a disruption of the homeostatic compensatory mechanisms under the toxicological threshold before achieving equilibrium. These behaviors have been men-

tioned within the field of ecotoxicology with the concept of hormesis. The reasons why there were no significant responses with the DE pyrethroid are not clear; however, the use of nominal concentrations, in addition to the small volume applied in sediment, may overestimate the concentrations assessed. From the point of view of risk assessment and environmental relevance, AP levels found in sediment, within a radius of 100 m around net pens, have reflected concentrations in the range of 14–44 µg/kg-1 for EB and 0.49 µg/kg-1 for CP. Other researchers have identified concentrations of CP between 8.27 and 71.9 µg/kg-1 in sediment of marine–estuarine areas in northeast Spain. No studies have found detectable DE concentrations in sediment. Consequently, EB measured concentrations are under an order of magnitude according to the levels of acute and sub-lethal toxicity reported for M. insidiosum in this study. However, EB potential to persist and accumulate in the sediment, considering periods of consecutive treatments in salmon, can present a worst-case scenario that may result in greater levels that generate toxic side effects. In contrast, sediment values reported for CP could trigger potential environmental risks or be mostly susceptible to the action on amphipods or other marine benthic invertebrates.

Conclusion Sediment bioassays performed with the amphipod M. insidiosum showed responses at different levels of the bio-

greater sensitivity to pyrethroid pesticides, such as CP and DE. Sub-lethal responses, such as induction in GST activity and lipid peroxidation, were affected by EB and CP in the short-term exposures, whereas concentrations tested with DE showed no significant antioxidant activity. Thus, biochemical responses may be unclear after a longer exposure time. In relation to concentrations measured in marine sediment, data showed that AP could cause a potential risk against the scenario of the intensive application of pesticides, in which low levels, mainly pyrethroids, would generate adverse consequences on M. insidiosum or other non-target organisms in areas with aquaculture activity. Future studies in sediment require greater attention on highly toxic pesticides such as DE. logical organization and appear to be a candidate for ecotoxicological studies. Through the experimental method,

it was possible to obtain contrasting results in relation to other marine organisms exposed to AP, which showed

Original article: Tucca, Felipe, Toxic Effects of Antiparasitic Pesticides Used by the Salmon Industry in the Marine Amphipod Monocorophium insidiosum. Archives of Environmental Contamination and Toxicology. Springer. e-Publication. March 8th, 2014.

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still growing

The 2014 Offshore Mariculture Conference confirmed that By the World Fishing & Aquaculture Staff*


ccording to conference chairman, Alessandro Lovatelli, aquaculture officer at the FAO, “the maximum sustainable potential from wild capture fisheries has been reached, but aquaculture is growing. And this is necessary to keep up with food consumption and the growing population”. The 5th Offshore Mariculture Conference, held from April 9th-11th, attracted over 100 delegates from 18 different countries to Caserta, Naples, in Italy. Participants included managing directors, investors, CEO’s and fish farm operators from companies such as BIM Irish Sea Fisheries Board, Carapax AB, PSP Investments, Cooke Aquaculture, Blue Ocean Mariculture, Cuna Del Mar and Badinotti Group SpA. The two day technical conference was opened by Pier Antonio Salvador, 40 »

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aquaculture is still the future. president of the Associazione Piscicoltori Italiani (API), who welcomed delegates to Naples and set the scene for the key note papers presented by José Aguilar-Manjarrez, Aquaculture Officer, FIRA and FAO, who opened up the debate on spatial planning, an important tool in helping both public administrations and investors, in identifying and allocating the most appropriate areas for future aquaculture. Paul Holthus, founding President/CEO, World Ocean Council, then covered international ocean policy developments and offshore aquaculture – global and regional actions affecting the future of business. Finally Kathrine Hawes, principal at Aquarius Lawyers, gave a lively presentation on the legal aspects of Offshore Mariculture. A series of presentations in session three concentrated on technological developments, most notice-

ably in cage design; the interest in the Q&A session demonstrated the need for such developments to take place in order for the industry to be able to move farther offshore. The first day concluded with presentations updating delegates on the success and challenges of projects last discussed or nurtured from the 2012 conference in Izmir, Turkey. In particular Toby Baxendale, UK entrepreneur, discussed the successful partnership between himself and Neil Sims and Kampachi Farms. Delegates learned from their first-hand experience how to launch a viable mariculture project and how to seek investment. The conference dinner was held on the first evening at the Historia Massa Restaurant, Caserta. All participants were keen to stay until the end to make the most of the excellent

food at the early 19th Century historic restaurant, a popular eatery in Caserta old town, which provided further opportunities for networking and to discuss the day’s topical issues. The second day began with a presentation delivered by Neil Sims, who presented his paper on water quality monitoring via telephone from Hawaii. He gave delegates an outline of the Ocean Stewards Institute’s white paper on water quality monitoring and the available science on water quality impacts around open ocean mariculture sites. He made the point that “fear mongering”, mainly by NGOs, badly affects the public’s perception of aquaculture. Mr. Sims was followed by Benen Dallaghan, who gave an interesting presentation on an organic salmon farming project in Galway Bay. Benen is responsible for GIS at BIM and he explained to delegates the use of GIS as part of the site selection process for the proposed farm. Yngvar Olesen, Norwegian University of Science and Technology, discussed how feed supplies can be produced for an expanding aquaculture industry in the future. In his concluding remarks he noted that it is likely to be the industrial biotechnology companies that will produce the feed resources in 2040, and that feed companies will likely continue to develop and optimize feed formulation. He also asked the question: will

Conference chairman, Alessandro Lovatelli, aquaculture officer at the FAO.

biotechnological companies take over feed producers, or will it be the opposite? The afternoon session featured several speakers involved in renewable ‘blue’ energy. The interesting concept of multi-use platforms, and preliminary project results were presented, and research into Multi-Trophic Aquaculture (IMTA) was also discussed. The final presentations from Darko Lisac, Refa Med Italy, and Alessandro Galioto from Azienda Ittica San Giorgio, gave an insight into the application of modern netting materials in offshore cages, and a case study on the Gaeta fish farm. A video of the farm in operation wetted delegates’ appetites in preparation for the tech-

P2G fish farm, where main species cultivated intensively are sea bass, sea bream and meagre.

nical visit to the P2G fish farm on the third and final day of the conference. To conclude the conference, Marianne Rasmussen-Coulling, events director, Mercator Media, announced that plans are already being made for the Offshore Mariculture Conference 2015 that is due to take place in Mexico in June. The visit to the P2G fish farm saw delegates heading out to sea to view the farm’s core business; the intensive farming of sea bass, sea bream and meagre. Delegates had the opportunity to see the 72 floating cages where 2,000 tons of the three farmed species are produced, from fry purchased from qualified and certified hatcheries. Each batch of product produced at P2G can be fully traced and identified throughout the whole value chain through software which allows real time information on batch number, quantity, feed, farming days, temperature, etc. After the visit to the cages and a boat tour, P2G hosted a fantastic seafood lunch in Gaeta, with a speech from the Mayor of Gaeta welcoming delegates to the town.

*More information on the 6th Offshore Mariculture Conference will be announced soon. Originally published in World Fishing & Aquaculture,

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World’s largest SPF shrimp broodstock supplier ramps up

in Hawaii

Shrimp Improvement System Group (SIS), the world’s largest SPF shrimp broodstock supplier, recently inaugurated its Hawaii Vannamei Nucleus Breeding Center at the Natural Energy Laboratory of Hawaii By Suzi Dominy

Authority (NELHA) in Kona-Kailua, on the Big Island of Hawaii.


he USD$10 million investment in state-of-the-art infrastructure includes more than 92,000 square feet under roof on two sites that cover 6.6 acres, housing a maturation hatchery building, nursery and growout buildings, two 5,000 square foot evaluation raceways and an effluent treatment facility. SISH is part of Singapore-headquartered Shrimp Improvement Systems Group Pte. Ltd., the world’s largest supplier of selectively bred, specific pathogen free (SPF) shrimp, with breeding operations in Hawaii, Florida, Singapore and India. Some 40% of shrimp broodstock sold by SIS comes from the Hawaii operation. For the past 15 years, SIS has conducted all Litopenaeus vannamei selective breeding activities in Florida. SISH president, Joe Tabrah explained that in addition to the obvious advantages of consolidating all breeding and management functions in a single location, the decision to relocate the nucleus breeding center to Hawaii stemmed from a need to replace aging and inadequate infrastructure. The new facilities will allow SIS to broaden the scope of the breeding program to select for more commercially desirable traits, improve breeding efficiency by 42 »

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Barbara Dalton, West Hawaii Representative of the Governor of the State of Hawaii, Neil Abercrombie, Joe Tabrah (third from left to right), President SISH and SIS Group senior management team join Kumu Keala Ching (center, in white shirt), Executive Director of Nā Wai Iwi Ola (NWIO) Foundation, who performed the official blessing ceremony.

accommodating improved generation intervals and provide for replicated trials for growth and other traits to provide improved performance data as a basis for selective breeding decisions, he said. “The NELHA location offers a location with no endemic shrimp viruses and a strictly enforced biosecurity policy”, SISH president, Joe Tabrah said. “It also offers more stable environmental conditions and avoids the high risk of hurricanes that we faced in the Florida Keys”. In addition to the commercial production of broodstock, SISH contin-

ues to invest more than USD$1.5 million a year into the selective breeding of Penaeus monodon with the expectation that this stock will be ready within the next two to three years. SISH has also recently developed an SPF stock of Pacific blue shrimp (L. stylirostris) which is also now being selectively bred. SISH currently generates revenues in excess of $9.5 million from broodstock shrimp sales. SISH plans to boost its staff from the 27 it now employs by a further 20, 16 of whom are being recruited locally.

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Chile prepares to host the largest aquaculture trade show in the

Southern Hemisphere In October 2014 By Stephen Newman

This year the international fair AquaSur will have more exhibitors and visitors than ever.


ccording to estimates of organizers (Editec), AquaSur’s 8th edition will gather more than 1,000 companies from around 50 countries in its 13,500 m2 of Trade Show space. Nineteen thousand visitors from five continents, among them entrepreneurs, investors, authorities, banks representatives, executives, 44 »

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professionals, foreign delegations, researchers, academics and media, are expected. AquaSur 2014, which is sponsored by Alltech and Hotel Manquehue and patronized by ProChile, the Undersecretary of Fisheries and Aquaculture (Subpesca), the Chilean - Norwegian Chamber of Commerce and the Association of the Chilean

Salmon Industry (SalmonChile), will be held between October 22nd - 25th in Puerto Montt (Los Lagos Region), city where aquaculture suppliers, distributors and manufacturers will be able to find the latest technologies and services the industry requires. “With this continued growth we show everybody in the aquaculture industry that all these years of effort have been worthwhile and that this fair enjoys international positioning. This year has exceeded our expectations compared to previous editions”, says the CEO of Editec, Cristián Solís. In previous editions, the exhibition, which is considered the most important aquaculture fair in the Southern Hemisphere, has grown in parallel with aquaculture and has accompanied its ups and downs. In addition, improvements have been made according to the sector’s requirements. In fact, since 2010 the event takes place at a new location, broader and with better access, situated at km 1,018, Ruta 5 Sur (route Puerto Montt - Puerto Varas).

International interest “We invite everybody to continue developing new technologies and creating multilateral networking. All this will help to create a better aquaculture, one that will generate employment, wealth for the territories where it is located and, most importantly, healthy food for the world”, concludes Editec’s CEO. Aquaculture Magazine will participate in AquaSur. We’ll be waiting to greet all of our subscribers, customers and friends there!

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Aquaculture in Regional Australia: Responding to Trade Externalities

The present paper shows the results of a study that researched the feasibility of farming mulloway as an opportunity for Australian prawn farmers from the northern New South Wales region to diversify their By Jeffrey A. Guy, Alistair McIlgorm, and Peter Waterman*


quaculture continues to be the fastest-growing, meat-producing sector in the world, growing from less than 1 million tons of annual production in 1950 to more than 50 million tons in 2008. Global per capita supply from aquaculture has increased from 0.7 kg in 1970 to 7.8 kg in 2008.

Black tiger prawn (Penaeus monodon)

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production base. Southeast Asian countries in particular have responded to this global demand with massive increases in lowcost aquaculture production. What does this mean for Australia’s aquaculture potential? As global production of many commodities, including seafood, is shifting to Asian countries that have the lowest costs of production, exports to Australia will provide

competition for local farmers competing in the same markets. Although aquaculture growth in Australia has been slower than that in Asia, it’s still Australia’s fastest-growing primary industry, accounting for 30% of national fisheries production and increasing in value by 13% / year since 1990. Seafood industry is Australia’s 4th most valuable food-based primary industry, after beef, wheat and milk. It occurs from the tropical north to the temperate south and is largely based in rural Australia. Currently, the bulk of Australian aquaculture gross value is sourced from relatively few ‘high value’ species. In 2008-09, the gross value of production (GVP) of the five main farmed groups was salmonids (USD$304.2 million), southern Bluefin tuna (USD$145.6 million), pearl oysters (USD$97.7 million), edible oysters (USD$82 million) and prawns (USD$52.5 million).

Prawn production in Australia and its implications The bulk of Australian prawn production comes from tropical north Queensland with other significant farming areas being the Mackay, and Gold Coast regions. Australian

prawn farms are managed intensively: average stocking densities are of up to 40 post-larvae/m2 in a total ponded area of around 750 ha. Pond production techniques are well developed and farms south of Mackay produce one summer crop a year while those in the tropical north have the potential to produce more. Black tiger prawn (Penaeus monodon) is the major farmed marine prawn species in Australia. However, this is also one of two main species (the other one being Litopenaeus vannamei) produced in Asia. This raises questions in relation to the likely impacts on the profitability and continued growth of prawn farming in Australia and the challenges producers face due to the globalization of seafood markets. There is a growing need for Australian aquaculture industries to develop appropriate response strategies to such drivers. Experience in other developed countries indicates the need for rural industries to provide diversification opportunities to remain competitive and avoid excessive reliance on a single species or commodity. At present, the Tasmanian salmon industry is the only aquaculture industry actively investigating this option. Prawn farmers diversifying into fish culture would add a large (50,000 tons) new national market to their existing business while having alternate species and markets also reduces the risk from serious disease and income fluctuation. By working with other species that can be reared in different seasons and with similar technology and facilities, resources are used more efficiently. One option for prawn farmers is to adapt their existing onsite hatchery facilities to finfish production. They can also rotate their crops, allowing the pond to recover from unfavorable changes resulting from the culture of a single species, making farming more sustainable. In 2008 the National Marine Science Centre started research into mulloway (Argyrosomus japonicus), as

a potential species for New South Wales (NSW) prawn farmers to diversify their production base. Mulloway is a carnivorous, temperate, euryhaline finfish of the family Sciaenidae, which is ideally suited to zones of northern NSW. A move to replace black tiger prawn aquaculture with it is a productive way of offsetting the impact of imported prawns, thus strengthening the rural economy. This paper presents a case study of the impact of Asian prawn imports on black tiger prawn (Penaeus monodon) production in northern NSW, Australia.

Materials and Methods Historical data on landings and unit gross value of fresh, chilled and fro-

zen prawn imports were obtained from the Australian Bureau of Agricultural and Resource Economics, which provides a comprehensive account of historical trends in, and the outlook for, Australian fisheries. NSW production data was sourced from the NSW Department of Primary Industries aquaculture production reports. A two year commercial pilot for a 96 ton converted prawn farm facility was used to assess the economic viability of mulloway farming in northern NSW. Analyses were applied to provide estimates of economic and financial feasibility for conversion to mulloway. Analysis uses a combination of experimental and best practice industry data. A standard investAquaculture Magazine

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ment appraisal net cash flow model was used which presents data in a format showing annual profit, cash flows and discounted cash flow analysis. The investment in the farm was analyzed over a 20-year time frame to produce a set of results that are specific to finfish production and the Australian aquaculture industry. Aquaculture is considered a highrisk investment and investors would expect venture assessment rates to be well above 5%. In this context, an 8% discount rate was chosen. The 18 ha owner-run mulloway farm began operation in 2008 and is located on Palmers Island (sub-tropical climate with summer temperatures of 25-40ºC). Clarence River is the source of brackish-saline water (temperatures ranging from 13-14ºC in July to 31-32ºC in January/February) and mulloway are grown in 12 earthen ponds which receive regular inputs of river-derived water from 48 »

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a central intake canal. Stock is fed a formulated, extruded, generic type marine fish diet, once or twice daily and oxygenation of pond water is maintained by paddle-wheel aeration. Fish reach market size (2 kg) in two years. Fingerlings (1 g) are stocked in 4 ponds that are netted to exclude predators at a density of 14,00015,000 fish / pond. They grow to ‘plate size’ (500-600 g) in one year. Individual ponds are then drainharvested, graded and split evenly (6,000-6,500 fish) into two ponds (large and small grade) for grow-out to market size. Fingerlings could be stocked in late September/early October each year to utilize all of the Austral summer growing season. 90% of juveniles survived the first 12 months and 95% survived over the last 12 months. Table 1 shows key production parameters and financial data. Full pro-

duction was assumed to be achievable by year three. Total capital outlay included the cost of land. Land value was derived from the original farm purchase price less those assets that could not be converted to mulloway culture (prawn hatchery and processing equipment) and then adjusted to reflect proportional use of the site (80%). The investment model also assumes that fingerlings are purchased and the farm can operate efficiently with a full-time manager, a skilled worker and one full time laborer with part time laborers at peak periods (Table 2). Conversion to mulloway farming requires exclusion netting over the ponds used for the year one fish. Experience with the host farm site has shown there can also be issues with the power system inherited from prawn farms (dropping back to twophase). Capital expenditure may be required for upgrade to three-phase power. Additional capital costs include harvest nets and lifting equipment (USD$18,434) for a combined total of USD$92,170. Model is sensitive to changes in a range of revenue and cost-impacting variables. A sensitivity analysis identified the risk implications for the commercial fish venture. For the base case, a series of 10% increases and 10% decreases were made to key revenue and cost variables to measure the change in the internal rate of return (IRR).

Results While imported prawns have long been contributors to the national prawn supply, this trend has grown alarmingly in the past decade. Over the 10 years to 2006-07, the quantity of imported shrimp more than doubled, while at the same time real average unit import prices fell by 30-40% (Fig. 1). In 2003-2004, combined volume of imports from India, Thailand and Vietnam almost doubled. During this period China began its rapid rise to become the top source of imported prawns. Landings of

imported Chinese prawns increased from 544 tons in 2004 to 8,469 tons by 2006-2007. Four major drivers have been identified for this growth: 1) the strong appreciation of the Australian dollar has made imports more attractive to Australians; 2) the massive expansion of low cost L. vannamei culture in Asia; 3) there are no barriers to entry of imported prawns into the Australian marketplace; 4) the absence of small Australian east coast wild school prawns due to decade-long drought. In addition, over this decade Australian prawn producers also faced rising wage, water and energy costs which affected their profitability. This in turn hampered market development and the product innovation necessary to stimulate local demand.

The impact on the NSW prawn farming industry Production of black tiger prawns in NSW peaked at 408.82 tons in 2002-

2003 prior to the import influx. At that time seven producers cultivated 134.3 ha with a production rate of 3.04 tons / ha / year. Industry has declined significantly from this date and in 2010-2011 two producers marketed 148 tons from 87.63 ha with a production rate 1.68 tons / hectare / year. This yield was worth USD$1.57 million, representing a direct gross value loss of USD$4.15 million (Fig. 2). However, the total impact on the Northern Rivers economy was much greater, at about USD$9.2 million. In NSW, the response to cheaper and smaller imported farmed prawns, was to scale back production in 2003 and focus on a larger, high quality product. Larger size grades (>25g), rarely face competition from imported product and gain a substantial price premium over smaller size grades. Stocking densities were lowered from 45-10 post-larvae/m2 in order to achieve larger grade prawns. This resulted in a downturn in output and productivity. The major super-

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on-investment criteria the project in year three shows a gross profit of USD$173,611.4 on the investment of USD$1’023,087. Thus, a return on capital employed of 17%. The assessment takes into account a staged increase in production of 56 tons / year in year two leading to maximum production of 96 tons in year three. Estimates of economic and financial feasibility and whole-farm profitability are summarized in Table 3.

Sensitivity analysis The degree of sensitivity to key variables over the lifetime of the investment was generated by altering the traditional investment appraisal cash flow model. Results indicate that revenue is the most sensitive variable reflecting price and quantity changes. Managing the quantity of mulloway market chains are the largest buyers are more than 10% cheaper, allowing produced and the price received at of NSW farmed black tiger prawns imports to quickly gain market share market will have the largest potential as 10 kg green or large-cooked whole in the supermarket sector. impact on returns over the lifetime or smaller grade IQF boxes that usuof the farm. ally sell from USD$11.52 to 15.2 / Economics of an alternative Controlling the cost of labor is kg depending on size. finfish species also required, as a 10% change would A significant portion of a farm’s The investment appraisal net cash impact the project IRR by 1.3%. Likeannual income is derived from the flow model indicates that when fully wise, a 10% overrun on capital investIQF product sold later in the year operational in year three, the annual ment would reduce the IRR of the through these outlets. However, revenue of USD$884,832 exceeds the project by 0.9% over the 20-year life this category is identical to the im- total annual cost of USD$711,220.6 of the project. Discussion surroundported frozen cooked BT prawns giving a benefit-cost ratio of 1.24. By ing the carbon tax may lead to elecfrom Thailand and Vietnam, which traditional profit-and-loss and return- tricity prices increasing. Producers weren’t aware of any compensation currently available from government. Discussion Asia’s economic rise has been increasing at an unprecedented pace and scale. Japan, South Korea, Singapore (and more recently, China and India) have doubled their income / person within a decade. China and India have also tripled their share of the global economy and increased their absolute economic size almost six fold. Asia’s extraordinary ascent has profound implications within regional Australia for people, businesses and institutions. Some regions and sectors have experienced strong growth in population, employment and income due to the strength of 50 »

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the mining sector. In contrast, some food producing regions, such as the Northern Rivers of NSW, are facing stiff global competition. Overall, those primary industries unable or too slow to adapt to increased competition have declined rapidly. Recent government statements of policy (‘white/green papers’) clearly acknowledge that Australia is entering a major transformative period in terms of international trade policy and domestic responses. This is demonstrated in the National Food Plan with respect to short, medium and long term planning to meet changing global and national demands for food. However, a major policy thrust of these documents is that competition from imported food is good for domestic consumers because it makes Australian producers more efficient and hence more productive. This ‘free-trade’ market position doesn’t take into account that many Australian producers are required to operate in an environment that has limited use of chemicals and antibi-

otics, and they must abide by much stricter controls on environmental impacts. This is not always the case in Southeast Asia. Rather, a ‘fair trade’ position would involve the imported product meeting the same regulations Australian producers adhere to. Despite this unleveled playing field, and a recent senate inquiry indicating that seafood imported largely from Southeast Asia was failing antibiotic tests, there has been an inadequate response from successive federal governments; at present only 5% of the imported catch is currently screened by the Australian Quarantine and Inspection Service (AQIS), a government controlled entity. In contrast, NSW producers must comply with relevant federal, state and local government laws and codes of practice.

Industry and peak body responses The larger Queensland prawn producers responded to their own cost-price squeeze in a number of ways. Some have exited the industry and converted

The growth in Asian imports of a range of food products has raised concerns regarding whether local farmers can compete with cheaper products.

their farms to barramundi (Lates calcarifer). Other producers are trialing cobia or black kingfish (Rachycentron canadum) along with several grouper species (Epinephelus spp.) as supplementary crops. Those remaining growers have intensified production. This has led to average yields in Queensland increasing from four tons / ha in 2007-2008 to six tons / ha in 2009-2010. Industry peak bodies such as the Australian Prawn Farmers Associa-

Sub-tropical and tropical climates at New South Walles allow producers to cultivate finfish such as mulloway. Photo courtesy of

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tion (APFA) and the National Aquaculture Council (NAC) have been proactive in demanding that all sides of politics support a clear system of country-of-origin labelling (COOL), so shoppers can make informed decisions about their seafood purchases. Unfortunately, Marketing studies demonstrate that Australian consumers are particularly sensitive to price when making their seafood purchasing decisions. More recently APFA has looked to stimulate Australian demand through marketing campaigns such as celebrating Queensland Day (by eating Queensland prawns) and a national branding strategy (“Love Australian Prawns”) that concentrates on a fresh premium quality whole product. The ban on imported frozen uncooked (raw) farmed and wild whole prawns in September 2007 also closed off this market segment for imports. In this context, the outlook for fresh whole prawns is still attractive, especially in August-September and/or December when traditionally there are supply shortfalls and prices are very strong.

There has also been a strong movement to have imported product subjected to the same food safety regulations as the domestic industry. But while this may help in the short term, this topic could have negative consequences across the entire seafood sector by reducing overall demand.

Is diversification the answer? Northern NSW is too cold in winter for BT prawn production (and tropical finfish species like barramundi) as at 20°C water temperature, growth and feeding ceases, and death can occur at 14-15°C. As a consequence, NSW farms produce only one summer crop and all prawns need to be harvested before winter, making them less productive and adaptable than tropical farms. These constraints were recognized in a national aquaculture viability study 20 years ago. This blunt economic assessment is still relevant in the light of the impacts of imported product on the northern NSW aquaculture prawn industry. This prompted investigation into other native prawn species that were more cold tolerant, such as the brown

mulloway (Argyrosomus japonicus). Photo courtesy of

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tiger prawn (Penaeus esculentus), banana prawn (Fenneropenaeus merguiensis) and the kuruma prawn (Penaeus japonicas). All species met with limited commercial success because of their inferior grow-out performance. It is unlikely that a temperate prawn species could be found that would give better economic returns than the BT prawn, and in this context, southern Queensland and northern NSW prawn farmers need to look for potential in other non-prawn species. The large scale, intensive culture of high value marine finfish is potentially Australia’s most lucrative aquaculture industry. Economic analyses indicate that mulloway farming at present is a reasonably profitable venture. Reduction in production costs has been achieved with a closely related fish, the meagre or shade fish (A. regius), which is a new species for the diversification of aquaculture in the Mediterranean region. In the past few years, its production and processing costs fell significantly with the FCR down from 2.5 to 0.9 - 1.2:1 and cheap fingerlings. This resulted in its rapid development from an emerging 296 tons of product in 2002 to mature industry, with 4,784 tons harvested in 2008.

Cost impediments and enhancing profitability A range of issues have been identified with regard to reducing costs and enhancing the profitability of the emerging mulloway aquaculture industry. Many of these impediments are common to other aquaculture enterprises and costs saving measures are well known and implemented. Feed and labor costs. Feed at USD$3.15 / kg / fish produced by year three is the largest single cost in mulloway aquaculture. This cost can be reduced by up to 20% if feed management (feed choice and how to ration that feed) is optimized. Specifically, reducing waste and improving FCRs through husbandry and improvements in delivery could lead to a saving of around USD$55,302

/ year. Currently, farm labor costs USD$1.47 / kg of fish produced in year three. This expense can be addressed through the scale, design and mechanization of feeding. Reports show mulloway feeding is particularly suited to electronically operated timer-controlled systems. Reliable low cost supply of juveniles. High fingerling costs (USD$0.97 / 35 mm fingerling) are acting as a disincentive for prawn farmers to invest in mulloway farming. Accessing or producing fingerlings at less cost than from the government hatchery is a high priority for industry and researchers are currently exploring the potential of modifying existing onsite prawn hatchery infrastructure for mulloway fry production, with the aim of halving seed stock costs. Market dominance and marketing. The domestic aquaculture finfish market is dominated by better known competing farmed fish products such as Atlantic salmon (Salmo salar), barramundi, rainbow trout (Oncorhynchus mykiss), and yellowtail kingfish (Seriola lalandi). Adequate investment in marketing is crucial to profitability. Industry experience to date indicates that if the producer can achieve an increase of just USD$0.23 / kg for mulloway from effective marketing, this should translate into additional USD$22,120.8 / year in gross revenue for the farm. Economies of scale. Production costs can also be reduced through economies of scale. The case study model examined in this paper is for only one size of farm. Economic analysis for land-based teraponids farming in Australia demonstrates the positive effects of larger farms. Returns are highly sensitive to scale factors such as farm size, market price and feed costs.

Current status of adoption of mulloway aquaculture To date only one Palmers Island prawn farm has been converted to finfish production. In 2010-2011

Mulloway finfish of the family Sciaenidae, which is ideally suited to zones of northern NSW. Its culture could replace black tiger prawn production in this region.

this operation had an output of 72 tons which sold at an average price of USD$8.76 / kg. There have been no attempts by the other three larger farms in the region to culture another commercial species with ponds either lying fallow or only used occasionally. This is quickly becoming a defining feature of rural areas within Australia. On the other hand, this also represents an unmet regional development opportunity as the land needed has already been alienated, key infrastructure is in place and the scientific evidence that underpins the innovation has been demonstrated. Adoption of mulloway aquaculture appears to be inhibited by 3 key factors: market price, length of production cycle and the impact of imports. The latter may be having a major effect on adoption because farmers are not willing to risk another venture. Considerable effort could be required to convince growers of the need to diversify and the identified benefits of making this move. Key features of innovations that affect the likelihood of adoption are: expected profitability (highly profitable innovations are more quickly adopted); degree of certainty about the outcomes; and the scale and complexity of investment required for change. Despite the converted prawn farm providing an effective demonstration of innovation, the absence of above normal profits from mulloway farming is making finfish entry less appealing. One way to catalyze adoption is through appropriate incentives. And this may be the best strategy considering the history of prawn farming business in the region and the impact of global markets on

local producers. Researchers argue that incentive schemes promote and reward desired behavior and can be designed to influence the input, process or the output of a project. As mulloway aquaculture promises to stimulate regional employment and economic growth, some early government support may be needed for this emerging industry.

Conclusions Product diversification is an acknowledged response for primary production including aquaculture where biophysical and socio-economic conditions are suitable. While diversification from prawns to finfish, such as mulloway has merit, profitability is currently restricting uptake and this is due in part to the high input costs associated with the early lifecycle stage of a new industry. Further applied research is needed, particularly on the major cost areas of diets, feeding and local fingerling production to make mulloway more competitive and encourage farmers to enter and grow the industry. However, transition from prawn to mulloway culture also appears to be a slow process and governments need to play a role by providing incentives for farmers to diversify, particularly if there is a desire to maintain the economic benefits of aquaculture to economically-challenged rural regions.

*Original article: Guy, Jeffrey A., Aquaculture in Regional Australia: Responding to Trade Externalities. Journal of Economic and Social Policy. Vol. 16 no. 1, 2014.

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Effect of Brand Equity across Seafood Products

Brand equity can be an important marketing strategy in the seafood marketing industry.

By Yoonsuk Lee and Jae Bong Chang*


bout 55% of seafood consumption in the U.S. during 2003-2011 was represented by shrimp, canned tuna and salmon. U.S. annual consumption of fish and shellfish has gradually decreased from 16.6 lb. / person in 2006 to 15 lb. / person in 2011, although consumption of the topmost seafood products has stayed stable. Approximately 3/4 of these products are fresh or frozen and canned seafood accounts for slightly less than 1/4 of the total. Tilapia is considered as the rising seafood in the fresh and frozen markets, as its consumption has steadily increased since year 2000. Unbreaded seafood products account for about 60% share in terms of quantity sold.

of having a well-known brand name, as it can generate more profits than private labels or store brands. Additionally, measuring brand equity can suggest the role of store brands in seafood products â&#x20AC;&#x201C; over the past decade market shares for store brands in grocery products have grown faster than market shares for national brands. Achieving brand equity can imply that people will show brand loyalty or commitment to repurchase products of a particular brand. Authors analyzed brand equity of seafood products with two goals: 1) to determine its effects on shrimp, salmon and tilapia via productsbased approaches, and 2) to analyze the role of store brands in said products in the U.S.

Brand equity The stable consumption of shrimp, salmon and tilapia in the U.S. over the last decade could imply the need for long-term strategic marketing investments as brands can be one of the most important assets in value investing for seafood markets. Brand equity measured in a marketing industry describes the value

Materials and methods Data was collected from several stores across 52 markets or metropolitan areas, including descriptions of particular products such as brand, size, form and formula on monthly sales. Types of store channels were categorized into three groups: drug stores, Food Drug and Mass stores, and Superstores. Procedure In order to identify national brands of shrimp, salmon and tilapia products, data was filtered by brand names; 57 brands were found for shrimp and 52 brand names were found for both salmon and tilapia. Well-known national brands were ranked by their 2010 annual sales, although itâ&#x20AC;&#x2122;s com-

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Market share or sales data are sensitive to distribution coverage and sales may be affected when a brand gains or loses a major market or expands into another geographic region. To avoid this particular issue, the market areas were referred to as U.S. total. Size of seafood products (oz.) vary depending on individual companies, and there are many different packing presentations of shrimp, salmon and tilapia products; to solve this issue, data was sorted only for the same presentation of products (fillet). There are several ways to determine brand equity: 1) at firm level, a brand is treated as financial assets, 2) at consumer level, brand awareness of a particular brand is analyzed via survey, and 3) at product level, market behaviors such as market share, market price, and distribution coverage of branded products are compared to equivalent private labels. Brand performance through market share is based on the idea that when brand has a relative advantage in the minds of customers, its market share should increase or at least not decrease.

plicated to rank these suppliers that way since there are a wide variety of seafood companies operating on very different business models. Wellknown brands displayed in the scanner data were matched with the top 20 seafood suppliers listed in Table 1. Since there’s a lack of well-known national brands, researchers considered the possibility of a negligible effect of brand equity on these products when national brands were compared with store brands. After selection of relatively wellknown brands, brand equity of shrimp, salmon and tilapia products was computed by estimating unit market share for each brand (units sold by each particular brand are divided by total market sales).

Implications Table 2 shows the market share of each brand for shrimp products. For unbreaded frozen shrimp, there were eight relatively well-known brands. Each well-known brand barely had any market share. Aqua Star and Beaver Street Fisheries, the top two companies in the market, accounted for about 2% each in 2012; almost any other brand had a market share of almost 0. However, store brands show a market share of around 60%. They are also branching into niches that lack national brand completion. Table 3 represents market shares of each brand of unbreaded frozen salmon products. Market share of Aqua Star has a relatively higher percentage of sales, but it has dramatically declined over the past few years. Market share of Trident Seafoods is smaller but has gradually increased. This shows that in salmon products markets, store brands have a higher market share than well-known brands as well. Table 4 represents market share of each brand for unbreaded frozen tilapia products, whose consumption has continuously increased. Beaver Street Fisheries

has a relatively high market share and has showed stability over the last years. However, store brands still present higher percentages of market share. Results indicate that there’s almost no brand equity on these products and market share of store brands outstands any competitors. However, one must be careful in interpreting this information. On a regular basis and for other food commodities, store brands perform better than well-known national brands when the economy is tough; besides, seafood isn’t consumed on a daily basis in the U.S. It’s difficult to discuss whether the performance of store brands in seafood markets is due to tough a economy or other factors such as the lack of national brand competition, unawareness or measurement errors with market shares.

Conclusions Measuring brand equity can create important implications for further strategies on seafood marketing industries. For an accurate measurement via market share, different marketing efforts made by companies, such as advertising and price deals should be considered as well. In order to support the existence of brand equity in this industry, future studies need to consider cognitive psychological factors that indirectly influence consumer’s choices, through a consumer survey. *Paper was presented at the Southern Agricultural Economics Association’s 2014 Annual Meeting, at Dallas, TX, on February 1st-4th, 2014. For more information on this study, please contact authors: Yoonsuk Lee: Jae Bong Chang:

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Perfect Seafood Portioning


ith the RevoPortioner from Marel Townsend Further Processing, fish processors can make perfectly portioned products at low pressure, while retaining the texture and structure of raw materials. This can be done without the need for additives to make it stick together, thus avoiding additional costs and keeping the fresh flavor of the fish intact. The RevoPortioner provides a unique opportunity for fish processors to add value to fresh fish products, turning trimmings into profitable opportunities. Consistent top-quality products such as fish cakes, fish burgers, seafood fantasy, and fish fillets, are made in an energy-efficient process with an unbeaten payback time.

The RevoPortioner line Under the brand of Townsend Fur-

What do you do with the trimmings and waste from your fresh block and mince products? Would you like to go a step further and develop innovative new seafood products? ther Processing, Marel offers a wide range of equipment for further processing of white meat, red meat and meat substitutes. Marel has a complete line of RevoPortioners that can process beef, poultry and meat mixes as well as non-meat products to give them any shape the processor desires. Each product will always have the same shape, weight, size and be of uniform quality. Since Marel came up with the RevoPortioner in 1999, as an innovative approach in portioning technology, they have amassed a vast amount of knowledge and research to deliver a range of machines that

serve the needs of many satisfied processors across the globe. The RevoPortioner 400 makes perfectly portioned products at low pressure whilst retaining the texture and structure of the raw material. The system releases products using only air. This leads to better product consistency and quality and an optimum control of the remaining processing steps. There is virtually no leakage of the mass. The RevoPortioner 400 presents the following features: • Standard 400mm belt width links up perfectly with the rest of your line. • Minimum leakage of meat mass. • Product release using only air instead of pushers and water. This benefits end-product quality and guarantees a clean working environment. • Quick and easy to operate; changing a portioning drum is an easy job that takes just a few minutes. Meanwhile, the RevoPortioner 500-600-700 covers all this features, while it presents one universal frame for three belt widths (500mm, 600mm, 700mm / 20”, 24”, 28”). See for more information. For media inquiries please contact: Liesbeth Janssen, Editor, Marel Townsend Further Processing

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I-Cut 130 PortionCutter for the salmon industry


he I-Cut 130 PortionCutter is the ideal solution for portioning of salmon into fixed-weight and fixedlength portions. It has been designed with the latest hardware and software technology which guarantees extreme accuracy, raw material optimization and maximum return on investment.

Razor sharp innovation The I-Cut 130 PortionCutter has unique features that enable salmon processing companies to produce high-quality products. It has been equipped with the new generation touchscreen and user-interface that makes daily operation and programming easier. It also features a powerful computer and a new laser vision system that ensure unmatched accuracy. Besides, the machine design features a built-in TrimSort and trim take-away system for efficient sorting of products on a separate outfeed. Key features The I-Cut 130 presents top-of-the-art hardware and software. Its powerful computer comes with proven motor technology for high-precision cutting and long lifetime, along with a new laser vision system with 200 Hz camera that ensures extreme accuracy. Its multiple cutting angles - 45°, 55°, 65° and 90° - increase plate coverage and enable innovative cutting

With more than 20 years of experience, Marel has developed the I-Cut 130 PortionCutter to enable salmon food processing companies to keep pace with the constantly escalating demands from customers such as supermarkets and restaurant chains.

patterns, at a speed of up to 1,000 cuts per minute. Other features include: easy-tooperate touchscreen for an easy daily operation; easy-cleaning design that follows the strictest hygiene standards; remote service access through Ethernet for maximum uptime (optional); built-in TrimSort and trim take-away system for efficient sorting on separate outfeed (optional); intelligent spacing between portions for a

higher throughput; Ropanyl belts for easy sanitization; and active product holders for an efficient product infeed and cutting of round and odd shaped products, among many others. In addition to this, the intelligent choice of cutting patterns ensures optimal use of raw materials. The I-Cut 130 can be integrated with other Marel equipment for optimized cutting and batching processes.

Examples of products

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Feed Report

Aquafeed Report for March, 2014

As we all know, the development and growth of aquaculture is dependent on the availability of suitable feeds; the status of the aquafeed industry is By Suzi Dominy*


n January the feed ingredient and additive company, Alltech, published the results of its second global feed survey, which provided yet another confirmation that aquaculture is expanding at an unprecedented rate. When analyzed by species, the survey showed aquaculture led the growth chart with a

Dr. Brett Glencross, CSIRO, conducted trials that show the complete replacement of all fishmeal and fish oil in shrimp diets can be achieved without loss of productivity. Photo: CSIRO.

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therefore a good reflection of the health of aquaculture. stunning 17 percent increase from 34.4 million metric tons (mmt) in 2012 to 40.36 mmt in 2013. (To keep things in perspective, however, overall global animal/aqua/pet feed tonnage was 963 mmt). It is no surprise that by region, the survey estimated Asia as having the largest production output, at 31 mmt, of which China accounted for 23.36 mmt. Europe followed a long way behind in second place, at 3.8 mmt, followed by Latin America at 3 mmt, North America at 2 mmt, the Middle East at 0.23 mmt and Africa at 0.194 mmt. Aquafeed production statistics are notoriously hard to nail down, not least because feed companies can be reluctant to release the information and government statistics in some countries are less than reliable. Alltech said they garnered theirs from information obtained from local feed associations and their sales team. This is probably as good an estimate as any we’ve seen but when looked at in a little more detail we have some difficulty reconciling some of the numbers. For example, Alltech told that Thailand produced 0.9 mmt aquafeed and Indonesia 1.2 mmt. From confidential conversations with some of the companies in those countries, we know this is vastly underestimated. Overall, however the survey does offer a useful

overview of the size and growth of the industry. That Europe is taking aquaculture seriously is evidenced by the start of the largest aquaculture research project ever funded by the European Union. The €11.8 million (USD$16.3 million) project, called DIVERSIFY, has 38 participating partners from Spain, France, Italy, Greece, Israel, Belgium, The Netherlands, Denmark, Norway, the United Kingdom, Germany and Hungary. The five year project will focus on the development of new and emerging finfish species, that have the potential to expand the European Union (EU) aquaculture industry. The species to be studied include meagre (Argyrosomus regius) and greater amberjack (Seriola dumerili), wreckfish (Polyprion americanus), Atlantic halibut (Hippoglossus hippoglossus), grey mullet (Mugil cephalus), and pikeperch (Sander lucioperca). DIVERSIFY will build on national initiatives for species diversification in aquaculture, in order to overcome known bottlenecks. The hatchery stage is a notorious bottleneck, and here, as in all stages of production, feed is at the foundation. Many hatchery operators are unaware that there are now excellent manufactured feeds available for a number of species. To help find out about these feeds and who makes them, our specialist web re-

source,, created The Hatchery Feed Guide & Year Book. In addition to manufactured feeds, the Guide also lists water conditioners, enrichment products and live feeds. The Guide is published in PDF-format, to allow users to link directly to datasheets, websites and email addresses. It is available for free download from

Protein alternatives Protein is always a hot topic in aquafeed circles and it was a subject of great interest at our two conferences. Aquafeed Horizons Asia, taking place in Bangkok, April 8th, and the feed ingredients and additives conference, FIAAP Conference Asia, that took place the following day, April 9th. Drawing particular interest at Aquafeed Horizons Asia is a novel bioactive feed ingredient which has been demonstrated not only to increase growth rate in shrimp from between 20 to 40% and provide protection to some known pathogens, and can also potentially reduce dependence on expensive and potentially unsustainable marine resources. This ingredient, called Novacq, was developed by the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia’s national science agency, and is soon to be commercialized for inclusion into shrimp diets. The feed company Ridley Aqua-Feed, which has commercialization rights in Australia and some SE Asian countries, is now embarking on the next stage of this project. Dr. Matthew Briggs summarized the results obtained when incorporating it into shrimp diets under both laboratory and commercial conditions, outline the challenging path to commercialization of the product into the global shrimp culture industry and the game changing implications this could have on the sustainability of the industry into the future. Good news for protein strapped European aquafeed manufacturers in 2013 was the revision of the ban

Protein is always a hot topic in aquafeed circles and it was a subject of great interest at Aquafeed Horizons Asia Bangkok, April 8th -, and the feed ingredients and additives conference, FIAAP Conference Asia - April 9th. on processed animal proteins (PAPS) from non-ruminants, that now allows their use in aquafeed. The ban was adopted as a control measure to prevent transmissible spongiform encephalopathy (TSE) and was the result of poor control of meat and bone meal in the animal feed chain in the past. However, the European Parliament insisted that any revision of the feed ban be accompanied by specific methods to identify the origin of the species of PAPs in feed, so that intra-species recycling and the presence of ruminant PAPs could be excluded. These methods also needed to guarantee the minimization of the risk of cross-contamination during the production process performed under a regime of strict spatial segregation. The R&D organization known as TNO Triskelion BV in the Netherlands has developed a ruminant-DNA specific Real-Time PCR (Polymerase Chain Reaction) method which can detect 0.1 % of ruminant PAPs in feed. This is of crucial interest for fulfillment of the requirements of the EU regulations. Dr. Gert van Duijn, Project manager, TNO Triskelion, discussed the method in detail at the FIAAP Conference. Details for the conferences, which take place alongside the region’s most important trade show for the feed, grain and biofuel industries, FIAAP/ VICTAM/GRAPAS Asia, can be found at

Suzi Dominy is the founding editor and publisher of She brings 25 years of experience in professional feed industry journalism and publishing. Before starting this company, she was co-publisher of the agri-food division of a major UK-based company, and editor of their major international feed magazine for 13 years.

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Probiotics in

Shrimp Aquaculture

Shrimp ranks as the most favorite seafood among US consumers, and more than half of the shrimp in the market are coming from aquaculture.

By Hui Gong*


fter decades of impressive growth, global shrimp aquaculture production in 2012 reached 3.78 million tons. However, catastrophic disease outbreaks have hindered the growing pace of the shrimp industry from time to time and caused tremendous economic loss, in billions of USD$ collectively. The most recent disease problem was the outbreak of the Early Mortality Syndrome (EMS) or “Acute Hepatopancreatic Necrosis Syndrome” (AHPNS), which was first reported in 2009. EMS has affected the shrimp farming industry greatly in much of Asia and Mexico, mostly targeting young animals within one month after stocking in ponds. Estimated economic losses due to EMS are over USD$1 billion per year. Substantial research efforts have been invested in finding the causes and cures, and the causative pathogen agent of EMS (AHPNS) was identified as a specific strain of Vibrio parahaemolyticus, which now can be detected via PCR tests. The mechanism of EMS pathogenicity is not fully understood yet. However, the mode of action is believed to be that the bacterium colonizes the shrimp gastrointestinal tract, producing a toxin that causes destruction and dysfunction of the hepatopancreas, which is the major digestive/ absorptive organ in shrimp, consequently resulting in mass mortality. V. parahaemolyticus is a common inhabitant of coastal and estuarine environments all over the world, and closely 60 »

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related to various shrimp pathogenic luminous bacteria such as V. harveyi, V. campbelli and V. owensii. It has been proven to be very difficult to eradicate these bacterial pathogens, if not impossible. Maintaining a good balance of microbiota in the digestive system of shrimp and in the culture environment to prevent any imbalance favoring the propagation and domination of pathogenic bacteria is probably a more sensible approach. Application of probiotics could play an important role in this aspect.

What are probiotics? The term “probiotic” comes from the Latin “for life”, and has had different popular meanings over the years. The term in modern aquaculture can often mean a bacterial supplement of a single or mixed culture of selected non-pathogenic strains. Parker described probiotics as organisms and substances that contribute to the intestinal microbial balance. Fuller provided a revised definition of probiotics as ‘a live microbial feed supplement which beneficially affects the host animal by improving its intestinal microbial balance.’ A newer version of the definition provided by the Food and Agricultural Organization and World Health Organization was ‘live microorganisms that when administered in adequate amounts confer a health benefit on the host.’ As for aquaculture, the bacteria present in the aquatic environment influence the composition of the gut biota as the host and microorganisms share

the ecosystem. Probiotics may act as a microbial dietary adjuvant that beneficially affects the host’s physiology by modulating mucosal and systemic immunity, as well as improving the nutritional and microbial balance in the intestinal tract.

Application of probiotics in shrimp aquaculture Application of probiotics in shrimp aquaculture is still in its very early stages and much more needs to be done as compared to uses in land animals and fish. Some probiotics- related research in shrimp and prawns is summarized in the Table below. Probiotics have been applied in shrimp during various developmental stages for different purposes. They have been used to condition the water in shrimp nursery tanks, to inhibit the growth of pathogenic agents and to maintain water quality in intensive aquaculture ponds. Studies have shown that administration of probiotics during early developmental stages can be more effective in preventing gastrointestinal associated disorders because the digestive tract and function are not fully developed and the immune system is still incomplete. Applying probiotics in shrimp culture can be categorized in three major ways: through feed, through water, and through a combination of feed and water. The majority of probiotics used in previous studies in shrimp and prawns are Lactic acid bacteria (Grampositive), Bacillus bacteria (Gram-positive), Vibrio alginolyticus (Gram-nega-

Table 1 Application of various probiotics in shrimp/prawn culture. Probiotic Bacillus sp. S11 Bacillus sp. Saccharomyces cerevisiae, S. exiguous, Phaffia rhodozyma Bacillus sp. Saccharomyces sp. Bacillus sp. 48 B. subtilis E20 B.s coagulan SC8168 Pediococcus acidilactici Bacillus NL 110, Vibrio NE 17 Bacillus spp Enterococcus sp P. pentosaceus, Staphylococcus hemolyticus B. subtilis, B. egaterium B. subtilis strains L10 and G1 B. subtilis

Used for Shrimp Species

Method of Application

Major Effect

Penaeus monodon Penaeids Litopenaeus vannamei

Feed Water Feed

Promoting growth Inhibiting pathogen Inhibiting pathogen

Penaeus monodon


Improving water quality

Penaeus monodon Litopenaeus vannamei Litopenaues vannamei

Water Feed Water

Improving water quality Promoting growth Improving water quality, survival

Litopenaeus stylirostris


Macrobrachium rosenbergii

Feed, Water

Farfantepenaeus brasiliensis


Stress tolerance Improving water quality& nutrient digestibility Inhibiting pathogen

Litopenaeus vannamei


Improve disease resistance

Litopenaeus vannamei


Stress tolerance

Litopenaeus vannamei


Macrobrachium rosenbergii

Feed, Water

Improve disease resistance and immunity Promoting growth and enhancing survival

tive), Nitrobacter spp. (Gram-negative), and some yeasts, such as Saccharomyces cerevisiae, S. exiguous, Phaffia rhodozyma, etc. Functions of probiotics vary, to a large extent. Some probiotics stimulate the host’s immune response, produce vitamins, detoxify compounds in the diet and break down indigestible components, while others may inhibit the growth of pathogenic bacteria by producing wide-spectrum inhibitory compounds. Probiotics may also benefit shrimp by competing for available nutrient substrates, space and even Iron in the microbiota in gastrointestinal environment, and/or altering water quality in the external environment. Consequently, the beneficial effects of probiotics to shrimp have generally been suggested as enhancing feed conversion efficiency, improving growth rates, protecting against pathogens and improving water quality.

es, both in the composition and/or activity of the gastrointestinal microflora that confers benefits upon host’s health conditions. In some cases, prebiotics may be beneficial for probiotic effects. Combined application of probiotics and prebiotics, is known as “synbiotics.” With prebiotic support, probiotics will thrive and survive well in hosts’ digestive systems. The synergism makes it possible for the application of synbiotics to achieve greater benefits than the application of probiotics alone. The application of synbiotics were found to provide beneficial effects such as improved disease resistance and growth, and enhanced survival post WSSV challenge in a couple of studies in Litopenaeus vannamei.

Quorum Sensing Quorum sensing (QS) is a process of bacterial cell-to-cell communication, which involves regulation of gene exSynbiosis pression in response to fluctuations A prebiotic is a selectively fermented in cell-population density. Quorum ingredient that allows specific chang- sensing bacteria produce and release

chemical signal molecules called autoinducers that increase in concentration as a function of cell density. The detection of a minimal threshold stimulatory concentration of an autoinducer leads to an alteration in gene expression. QS cascade can occur both intra- and inter-species via specific autoinducers, which elicit specific responses. Although the nature of the chemical signals, the signal relay mechanisms, and the target genes controlled by bacterial quorum sensing systems differ in every case, the ability to communicate with one another allows bacteria to coordinate their gene expression, and therefore the behavior of the entire community. Virulent bacteria can launch an attack on the host with QS controlling the pathogenicity. Gaining understanding of the mechanism how V. parahaemolyticus causes EMS in shrimp is crucial and developing specific chemical molecules that could either impede certain QS of this causative bacteria or promote some alternate QS might be helpful in coming up with new antiinfective strategies in shrimp aquaculture. With the rapid advancement of biotechnologies in the recent years, there is no doubt that more in-depth knowledge of probiotics can be gained, and that proper application of probiotics/prebiotics could achieve greater positive impacts in shrimp aquaculture production.

Hui Gong, PhD, is an Associate Professor at the College of Natural and Applied Sciences at the University of Guam. Her expertise in shrimp aquaculture has built on 17 years of experience in applied research in both academic and industrial backgrounds.

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Marine Finfish Aquaculture

Table talk from

Aquaculture America 2014 Aquaculture America 2014 recently came and went at the Seattle Convention Center. According to Conference management, there were 1800 attendees from 62 countries who contributed to 606 oral and 132 poster presentations.

By Mark Drawbridge *


s its name suggests, Aquaculture America is dominated by aquaculture interests and attendees from North America. This is especially true when compared to the Triennial Aquaculture Conference at the World Aquaculture Society Conference, which is being held in Australia this coming June. Regardless, marine finfish were well represented among the many sessions covering a diversity of important topics that typify this conference. From a geographic standpoint, the southeast USA was the most prominent throughout the conference pro-

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gram with respect to a diversity of marine finfish aquaculture research activities. Species like cobia (Rachycentron canadum), Florida pompano (Trachinotus carolinus), spotted sea trout (Cynoscion nebulosus) and red drum (Sciaenops ocellatus) continue to receive attention as top candidate species in that area – either for food production, stock enhancement or both. Other species like mahi-mahi (Coryphaena hippurus), giant grouper (Epinephelus lanceolatus) and marine ornamentals like yellow tangs (Zebrasoma flavescens) were also reported on. In the southwest, white seabass (Atractoscion nobilis) and California yellowtail (Seriola lalandi) were the subjects of numerous research papers that also revealed the recent commercialization of those species in Mexican waters. Another commercialized aquaculture species, the sablefish (Anoplopoma fimbria), was the main subject of discussion central to the northwest, al-

though presenters discussed activities in Canada and as far south as Mexico, which is indicative of the natural range of this species. Facilitated by the location of the conference in Seattle, researchers from NOAA’s Northwest Fisheries Science Center were able to fill a half day session on this species and showcase the extensive research being conducted at their laboratory facilities and elsewhere. Surprisingly, research activities on marine finfish aquaculture in the Northeast went largely unreported at this particular meeting. Researchers from outside the USA reported a handful of papers on well known marine fishes like sea bass, sea bream, flounder and yellowtail. These papers are always well received, because they typically represent culture refinements to commercial success stories. Colleagues in Mexico reported on their work with two promising drum species – the gulf corvina (Cynoscion othonopterus) and totoaba (Totoaba macdonaldi).

From a topical perspective, perhaps not surprisingly for emerging species, research in marine finfish nutrition was at the forefront. Even in the larval rearing section, which was dominated by talks on marine fishes, researchers reported on their ongoing quest to refine protocols and quality of live feeds, and to optimize feeding regimes, especially in the co-feeding phase. Reducing reliance on live feeds continues to be a focus of research and in that regard research teams are seeking to develop and test open formula microdiets that can subsequently be optimized for each species. Other nutrition sessions encompassing talks on marine fishes included the use of soy in aquaculture; general nutrition; taurine; pre-biotics, probiotics, and immunostimulants; lipids; and ingredient evaluations. While there clearly remains plenty of research to do in determining basic nutritional requirements for many of the species, much research continues to be focused on enhancing the economic and environmental sustainability of diets relative to alternative ingredients to traditional sources of fish meal and oil. The importance of taurine in diets of marine fish continues to receive great attention. The topic garnered a half day session at the conference with eight of nine species-specific papers focused on marine fish. The importance reported is two-fold – first as alternative ingredients are explored for growout diets, taurine is often deficient, and secondly, traditional live feeds like rotifers are deficient when compared to natural live prey like copepods. Using fish nutrition as an example, the scientific productivity bound in the conference program was remarkable, especially acknowledging the economic down turn and the associated competition for fewer and fewer research dollars in recent years. For those seeking expertise in this arena in the USA, the government laboratories of Barrows at USDA and Johnson at NOAA NWFSC are clear goto centers. Trushenski’s laboratory at Southern Illinois University is very

The scientific productivity bound in the conference program was remarkable, especially acknowledging the economic down turn and the associated competition for fewer and fewer research dollars in recent years. active and clearly illustrates the fact that collaborative research on marine fish does not have to be limited to coastal states. The Gulf of Mexico is loaded with expertise coming from the Davis laboratory at Auburn and Gatlin’s laboratory at Texas A&M. The Langdon laboratory at Oregon State University is focused on larval nutrition and continues to innovate in that sector. In light of the economic climate, the tenor at the conference remained one of optimism for growth in the marine finfish farming sector. Reports of commercially acceptable survival rates permeated the discussions with an acknowledgement that additional refinements could greatly improve seed quality and overall robustness. Of course, commercial farming success stories for marine fish remain elusive in the USA as regulators and politicians continue to wrestle with a meaningful commitment to foster industry development in ocean waters. Progress using recirculating aquaculture systems for marine fish was not reported at this particular conference but clearly that remains an opportunity that bypasses the regulatory/political conundrum surrounding ocean farming. Fortunately, the collegiality and shared research findings associated with conferences like Aquaculture America ensure progress in the sector as a whole. More and more of the fruits of these labors are showing up on restaurant menus for all to enjoy!

Mark Drawbridge has a B.S. degree in biology and a Master’s degree in Marine Ecology. He’s currently a Senior Research Scientist at Hubbs-SeaWorld Research Institute in San Diego, where he also serves as the Director of the aquaculture program.

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Offshore Aquaculture

A call

to action By Neil Anthony Sims*

So how much “action” was there, really, at the Global Ocean Action Summit for Food Security and Blue Growth” held in The Hague, in the Netherlands, from April 22nd – 25th?


ne might have hoped for more, given the plight of our Oceans. An International New York Times cartoonist depicted our collective efforts as an eyedropper into an ocean of excuses. Most deeply alarming was Professor Hough-Goldburg’s plenary presentation, which detailed the massive momentum of global climate change and ocean acidification, and the inevitability of these both to impact all life within the oceans. Hough-Goldburg was one of the lead authors on the recent International Panel on Climate Change report, which should have slapped awake anyone who has been dozing off during recent climate change discussions. The synopsis: it is going to get real ugly out there, folks. The concept of “Blue Growth” -innovative, sustainable ocean-related industries -- has been much bandied about of late, as a banner around which aquaculture, fisheries and marine conservation interests might jointly rally. At the Summit, however, the lion’s share of the focus was on restructuring fisheries for greater equitability, ensuring ownership rights and access for small-scale fisherfolk, empowering women in fisheries, and fully valuing the natural capital of our oceans. To be sure, these are all valid and valuable discussions. But are they avenues for Blue Growth? 64 »

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The few fish farmers in attendance (one could count them on three fingers) felt a bit like red-headed stepchildren. A panel on Blue Bonds – i.e. financing mechanisms such as impact investing that could drive Blue Growth, and might be used to finance aquaculture – made not a single mention of aquaculture over the course of an hour and a half discussion (until your columnist asked the awkward question). FAO – one of the sponsors of the Summit – repeatedly informs us of the disturbing proportion of wild fish stocks that are already being exploited at or above their Maximum Sustainable Yield. There would seem to be much that can be done in reallocation of fisheries resources, or improving efficiencies … but these actions would not lead to growth, per se. Any reader of this magazine – along with FAO and the World Bank (the other major Summit sponsor) -- already knows where future growth will come from, and where it must come from: aquaculture. For many years, the conservation community was united in their antiaquaculture stance. Gradually, the true NGO thought-leaders have come to see the potential for aquaculture to be better, and to do good, and they have “come out” to varying degrees. The World Wildlife Fund, under the visionary leadership of Jason Clay, recognized the need to be encouraging

the right types of aquaculture, rather than besmirching the whole ball of wax, and hoping that fish farming just went away. From the resulting Dialogue process sprang the Aquaculture Stewardship Council, which is now being recognized as the most rigorous metric of responsible aquaculture, and one that should be embraceable by all. The Nature Conservancy is also now moving towards a more collaborative model for working with the industry. Most pivotal was Conservation International’s “Blue Frontiers” report (from 2012; compiled in conjunction with WorldFish Center). A copy of this should have been in every Summit participant’s hands, and we all should cite it often. This study consisted of an objective Life-Cycle Analysis (LCA) of the ecological efficiencies of a whole range of animal proteins (beef, pork, chicken, fish). LCA is an analysis of water, land, energy and green-house gas emission impacts, and this study concluded that handsdown, far-and-away, aquaculture was the least impactful of all animal protein production systems (due largely to the methane and nitrous-oxide emissions from land animals). This has broad and deep implications, given the growth in animal protein consumption that is projected with 3 billion global citizens rising into the middle class over the next few decades. As Professor Hough-Goldburg pointed out in the Summit Plenary, if these 3 billion start eating beef, the planet will be (to use the French)

At some point in the future, growth in open ocean aquaculture will need to expand into Areas Beyond National Jurisdiction (ABNJ). FAO was told by its member countries that type of aquaculture was 20 Kampachi Farms’ Researcher Gavin Key tends the 132 cu meter Aquapod that is part of the Velella Gamma array, located 6 Nm offshore of Kona, Hawaii, in 6,000 ft of water. The operation of the experimental array is controlled by remote wireless connection, so that the fish can be fed twice per day through a web-based server, anywhere in the world. The crew normally needs to service the array only on a weekly basis, to replenish feed hoppers and top up the generator fuel tank. Photo credit: Jeff Milisen © Kampachi Farms, LLC

or 30 years away, if ever. Aquaculture Magazine

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Offshore Aquaculture

There is increasing recognition of the benefits that offshore mariculture can provide to recreational fishermen. In this photo, a bevy of small-scale Hawaiian fishing boats dropline for tuna around the Velella Beta-test array (the drifting net pen project that operated off the coast of Kona in 2011-2012). This image shows 8 of the 16 small boats that were fishing in the area. The Velella Beta-test and Velella Gamma arrays have proven to be excellent Fish Aggregating Devices, providing increased catches to local Hawaiian fishermen for far less effort (and boat fuel) expended. The Velella Gamma array, which is now anchored offshore, is currently the most popular fishing site offshore of Kona. Photo credit: Neil Anthony Sims © Kampachi Farms, LLC

screwed. We therefore need to be creating desirable seafood products that are priced affordably, and that people choose to eat, rather than methanepumping, nitrous-oxide emitting bovines and other beasts. The large remainder of NGOs are now mostly silent on the need for aquaculture expansion, after the last few decades of denial. They still cling to the belief that only land-based culture systems are truly sustainable. The much-ballyhooed Fish 2.0 business competition for innovation in seafood – sponsored by many of the leading foundations in the field – explicitly excluded the culture of fish in net pens. (Huh? If you say a system is bad, then isn’t that where you would want to support innovation?!) And the economics of marine RAS systems are not yet fully proven at any meaningful scale. And freshwater fish – while a great source of protein to meet the needs of the planet’s poorer population – will not slake the growing desire for greattasting marine fish fillets, and sushi. No-one would ever suggest we force the burgeoning middle class to settle for carp carpaccio, or catfish sushi, any more than we could or should mandate veganism, or bicycling to work. 66 »

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This is why open ocean aquaculture needs to be a significant part of that future growth in aquaculture. Not just because we can. Though to be sure, expansion of commercial operations will be easier wherever there is opportunity to expand, less competition for ocean space, less need for land, water or energy, and where there is less potential for environmental impacts (i.e. further offshore). But more so, because the open ocean is where we can start to achieve efficiencies of scale with the tunas, groupers, snappers and yellowtails that people will want to eat instead of burgers. Abundant, scalable, increasingly affordable marine fish fillets could and should drive the shift in protein consumption patterns that we need, and might therefore offer some better hope to literally save the planet. At some point in the future, growth in open ocean aquaculture will need to expand into Areas Beyond National Jurisdiction (ABNJ, or what used to be called High Seas). The Offshore Mariculture Conference in Izmir, Turkey, in 2012, had called for FAO to start examining the need for a regulatory structure for aquaculture in ABNJ, to help provide some certainty for future

investors (in the face of increasing restrictions on other activities in the High Seas, such as “iron-seeding” experiments), and to prevent a repeat of the unbridled expansion in intensive cultivation, such as occurred in the 10th Region in Chile until ISA came calling. FAO was told by its member countries (who dictate FAO’s work plan) that High Seas aquaculture was not important; that it was 20 or 30 years away, if ever. Yet the Mediterranean has the idiosyncrasy of having only Territorial Seas, and no declared EEZs, so national jurisdiction ends, for many countries, a mere 6 Nm offshore. Six miles?! Brian O’Hanlon’s Open Blue commercial cobia operation in Panama is already 8 Nm offshore, and he produced almost 1,000 tons last year. We at Kampachi Farms, in Kona, have an unmanned Aquapod pen on a singlepoint mooring 6 Nm offshore in 2,000 m of water, with feeding controlled from shore by an iPad. We know of at least one project which has plans within the next year to launch an offshore fish pen into the High Seas in the Mediterranean. The future is coming, and the world needs to be ready for it. The subsequent Offshore Mariculture Conference in Naples, just prior to the Hague Summit, reiterated the plea from Izmir, for someone to start paying attention. The Global Ocean Action Summit in The Hague took note of this, and mentioned the need in the final Report. All we need now is some action.

Neil Anthony Sims is co-Founder and CEO of Kampachi Farms, LLC, based in Kona, Hawaii, and in La Paz, Mexico. He’s also the founding President of the Ocean Stewards Institute, and sits on the Steering Committee for the Seriola-Cobia Aquaculture Dialogue and the Technical Advisory Group for the WWF-sponsored Aquaculture Stewardship Council.

Latin AmericaN Report

Current trends in Latin American Aquaculture

This issue’s contribution will focus on Peruvian, Honduran, and Mexican aquaculture.

By Nicolás Hurtado*


Peruvian Aquaculture ver 50% of the tilapia sold in Peru is produced overseas. Last year, Peru imported more than 1,350 tons of tilapia, of which a large percentage came from China. Something similar happened with catfish, of which 1,850 tons of steaks were imported, mainly from Vietnam. “Many don’t know these are imported species. It´s good that people are informed in order to make decisions, especially because everybody prefers a fresh fish”, said Jorge Luis Favre, CEO of Acuahuaura. This shows the enormous potential of Peruvian aquaculture of many species, as the country has ideal environmental conditions and countless aquatic resources.

the fresh tilapia fillet segment, after this country became the largest exporter of this product to the US market. The only Honduran exporter of this species is Aquafinca (with Swiss funding), with headquarters in San Francisco de Yojoa, after the other exporter that was engaged in the same activity ceased operations in 2008. Orlando Delgado, Aquafinca’s CEO, projects a record 21.6 million pounds of production, or an income of about USD$70 million.

Mexico: inauguration of a tilapia farm With 27 floating cages that will provide work to more than 30 Mexican families, a tilapia farm was inaugurated on March 1st by Sinaloa’s citizens and authorities. Maria del Rosario Honduras, first tilapia fillet Alapizco, the project’s main promotexporter to the USA Honduras is again in the global po- er, informed that this required an dium. This time the prize goes to investment of USD$400 thousand, provided by the State’s Government. This project will use a peripheral model for tilapia culture; floating cages are made of blacksmith material with 200 l plastic floats. Tilapia is one of the main culture species worldwide (over 3.7 million tons), China being the largest producer with 1.35 million tons per year. In Latin America, Brazil is the main producer of this species with Photo courtesy of Nicolás Hurtado. more than 190 thousand tons.

Nicolás Hurtado Totocayo has a degree in Aquaculture Engineering and a Master in Business Management from Federico Villarreal National University (Peru). He is a founding member of the Peruvian Association of Aquaculture Professionals (ASSPPPAC), and is its current President. He also works as an Aquaculture Consultant.

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Genetics and Breeding

Inbreeding: It’s All Relative(s)

Many aquaculture producers share the ever-present suspicion that their production stocks are, or may become, “inbred.”

By Greg Lutz*


ore often than not, this is a reasonable concern. Most aquaculture operations are already working with stocks that are at least partially “inbred.” Most of these operations are still quite competitive and profitable, however, because the real danger from inbreeding occurs if it is left to follow a random course. Controlled inbreeding, of course, has a name we all recognize: SELECTION. Sounds familiar (pun intended)? This type of inbreeding,

of course, has been proven to be a very effective approach to genetic improvement. Whenever someone boasts about fish, or shrimp, or mollusks that have undergone rigorous selection for some trait or another, they are talking about comparatively inbred animals. Most established varieties of livestock, ornamental plants, and aquatic species in the aquarium trade are the product of intense inbreeding, and yet these organisms persist and are cultured profitably. Inbreed-

Random, undirected inbreeding can result in the loss of superior traits over a short period of time.

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ing can be defined simply as the mating of two individuals whose degree of relationship is higher than the expected, or average, value would be if members of the population were allowed to mate randomly. By way of review, let’s remember that chromosomes are paired within each cell of an organism, with the two chromosomes in a pair having the same regions coding for the gene products that affect particular traits. Each region on a chromosome, with its own particular genetic products, is referred to as a “locus.” Within an organism, there can be no more than two forms of a gene (“alleles”) for any given locus, because there are only two (paired) chromosomes that include that particular locus. If both forms of the gene are identical, the organism is “homozygous” at that locus. All of its offspring will inherit that particular allele, because that is the only one it possesses. If two different forms of the gene are present at the locus – with each chromosome producing a different gene product, the organism is “heterozygous” at that locus. On average, half of its offspring will inherit one of the alleles it carries and half will inherit the other allele. Simple stuff, really. A practical way to look at inbreeding is by determining the probability that both alleles (forms of a gene) at any given locus (point on a chromosome where that gene exists) are identical by descent from a common an-

cestor. There is a 50% chance of two offspring from the same individual inheriting the same allele at a given locus, and a 50% chance for every generation thereafter that that particular allele will be passed on from parent to offspring (because an individual only carries two alleles for the gene in question – one on either chromosome of the pair where we find that particular locus). Now, people often forget that most genes in most organisms only have a few common forms, so an organism can have identical alleles at many loci without necessarily being “inbred” at all. Many organisms have only one form of a gene at most of their loci. This allows populations and species to be differentiated in many biological and ecological studies. It also allows for performance to be improved when animals and plants are crossbred or hybridized. So… as you scratch your head you are still wondering why inbreeding is a bad thing. It is intrinsically linked to the concept of dominance. As we have just seen, for any given “gene” - organisms have two forms of that gene (alleles) at the locus in question. When dominance is present, one form of that gene can partially or completely mask the expression of the other form. In traits associated with fitness, inbreeding depression is thought to result from ‘directional dominance’ at the majority of loci affecting the trait. Directional dominance in this sense means dominance in the direction of increasing (improving) fitness. So, the “better” alleles tend to be dominant over the “inferior” alleles. Theoretically, this is an oversimplification, but it helps in a discussion of inbreeding. Breeding between more closelyrelated individuals tends to increase homozygosity (the presence of two identical gene forms) at all loci. So, as closed populations reproduce over a number of generations all alleles tend toward becoming fixed, one way or the other. The term fixed simply means that over time one gene form

Selection for growth may contribute to inbreeding levels over time in closed populations.

or another becomes more and more prevalent until the other gene forms simply disappear from the population. The larger the population, the longer this may take. As this process runs its course, many of those inferior gene forms, whose expression would normally be masked, become increasingly common. Just by the fact that mating more closely related individuals increases the number of animals who can only pass on one particular gene form… be it superior OR inferior. As a consequence inbreeding results in a reduction of the mean values of traits associated with fitness (specifically in the direction of the less dominant alleles) when the effects of all the genes impacting the traits are considered together. Inbreeding, by its very nature, is of greater concern in small populations, where random “sampling” in the formation of genotypes from an available pool of gametes can result

in the eventual exclusion of certain alleles and the fixation of others. The smaller the effective population number, the greater the incremental increase in inbreeding per generation, and once inbreeding levels have accumulated within a population, they cannot be reduced simply by increasing the population number. At that point, it’s not a question of the number of animals one has to work with, but rather the number of alleles. At the very least, if inbreeding is unavoidable due to limited facilities it can be offset somewhat through rigorous selection for fitness-related traits. Additionally, a breeding population can be divided into two or more sub-populations, each under selection for production- and fitness-related traits. These lines can then be crossed regularly to produce fingerlings for growout purposes, in theory reducing the overall inbreeding load in the commercial stock. If individual animals can be marked Aquaculture Magazine

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Genetics and Breeding

Developing synthetic strains such as many lines of red tilapia inevitably results in some unavoidable inbreeding.

and tracked, pedigrees can be used to mate the least-related individuals within a population, but this tends to simply delay the inevitable in many situations. And, it often results in the use of inferior breeding stock simply to minimize inbreeding at the expense of selection gains. How much inbreeding is too much? How can it be measured? Inbreeding is a relative concern (no pun intended this time). It must be gauged against some arbitrarily-identified base population. While many quantitative genetics texts address the calculation of inbreeding coefficients for individual breeding animals, this approach often has little use in commercial production of aquatic species. An inbreeding coefficient serves to describe homozygosity within an individual, but only that homozygosity resulting from inheritance of alleles that are alike by descent: alleles originating from a common ancestor. So, the calculation of an inbreeding coefficient must also take into account the level of inbreeding in any common ancestor(s), but pedigrees are often impossible to trace back far enough to allow for much precision. The pedigree information required for individual fish, crustaceans or 70 »

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shellfish is usually unavailable or entirely impractical to generate. For most purposes, the accumulation of additional inbreeding can only be tracked over time for each captive generation of the breeding population in question. In most cases, this can be estimated as: 1/(2*Ne) where Ne is the effective number of breeding individuals. And Ne is (4*Nm*Nf)/(Nm+Nf) where Nm is the number of breeding males and Nf is the number of breeding females. However, many individuals may not actually contribute much in terms of breeding due to behavioral hierarchies or biological factors. If the base population for a commercial hatchery was originally 80% heterozygotic, as might be the case if two distinctly different strains were crossed and then the offspring used as the initial breeding stock, and an inbreeding coefficient of 0.30 has accumulated, then (0.30)*(80%), or 24%, of the original heterozygotic loci can be expected to have become homozygous due to inbreeding. The resultant level of heterozygosity is now 80%-24%, or 56%. When available, however, pedigree information allows a much better estimation of inbreeding levels than simply tracking population numbers from generation to generation. Pante, Gjerde and McMillan reported on inbreeding levels in rainbow trout (Oncorhynchus mykiss) from three isolated populations. Inbreeding levels were calculated based on pedigree information (which in this case was available), and on effective population size. After the initial generations, levels of inbreeding estimated from population numbers were lower than those calculated using pedigrees. For the three populations, average rates of inbreeding calculated from population sizes were 0.99%, 0.90%, and 0.72%. Corresponding average rates calculated from pedigree information were 2.00%, 0.53%, and 1.38%,

respectively. This is because all individuals do not contribute equally – some males (and often some females) produce more than their “fair” share of the next generation. These inbreeding values were considered acceptable, based on data presented by Meuwissen and Woolliams (1994), which suggested inbreeding levels of 0.2% to 2.0% should not cause any loss of fitness. However, in a companion study, the authors determined that the actual inbreeding effect might vary between populations due to the distributions of inbreeding coefficients within each generation. That is, some individuals might be much more highly inbred than others. Taking this into account with statistical models that included sires and dams, as well as additive and dominance genetic effects, the authors determined that inbreeding effects might actually be somewhat higher. For the three populations in question, inbreeding effect on body weight at harvest, calculated from the more complex statistical models, was determined to range from -1.6% to -5.0%. Nonetheless, these impacts were not considered significantly serious to impact the selective breeding programs being carried out with these fish. Again, one strategy available to producers with limited facilities involves maintaining separate lines,

One of the available Genetics strategies for producers with limited facilities involves maintaining separate lines, subjected to intense selection, and crossing them to produce juveniles for growout.

In rainbow trout, as in many aquatic species, unequal reproductive contributions can lead to more rapid accumulation of inbreeding than would be predicted solely by populations numbers.

subjected to intense selection, and crossing them to produce juveniles for growout. In a study of inbreeding in Ostrea edulis, the European oyster, Naciri-Graven examined three populations that had previously been selected (read: INBRED) for resistance to the protozoan parasite Bonamia ostreae. In addition to these three populations, a population comprised of their crossbreds was studied, as well as a control population. Each population was composed of full-sib families derived from individual oysters that had been genotyped using microsatellite markers. In this way, the authors knew not only the parentage of specific oysters, but also the degree of relatedness of the parents. Inbreeding depression could be evaluated by comparing the relatedness of parents with the growth performance of their offspring. Growth was monitored for 10 months. At the end of the grow-out period, the crossbred population had the highest growth rate and, of course, the lowest level of inbreeding. Within the selected populations, although all exhibited high levels of inbreeding, the rankings in both growth rate

and inbreeding levels were similar. So, crossbreeding produced the best growth, but inbreeding still resulted in good growthâ&#x20AC;Ś once again, this phenomenon reflects prior selection. The slowest growing population in the study was the control group. Similar results were reported for Pacific oysters, Crassostrea gigas, by Pace and Manahan. They examined growth rates and feeding rates for crossbred and inbred C. gigas larvae. In four separate experiments, each involving 2 or more inbred lines, crossbreds exhibited superior performance, not only in growth but in size-specific feeding activity. At any given size, crossbred larvae were ingesting more algae than their inbred counterparts.

Got a genetics-related topic youâ&#x20AC;&#x2122;d like to see covered here? Send me a note at

C. Greg Lutz, has a PhD in Wildlife and Fisheries Science from the Louisiana State University. His interests include recirculating system technology and population dynamics, quantitative genetics and multivariate analyses and the use of web based technology for result-demonstration methods.

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European Report

European aquaculture

enters a new and promising stage The expansion of aquaculture in the European Union (EU), both for finfish and shellfish, suffered a sudden change in its development By Javier Ojeda*


rowth stopped and for some species, a steady decline started, even though at the time European aquaculture offered high quality products and operated under strict environmental, animal health and consumer protection standards. That this change in trajectory happened as the year 2000 arrived hopefully had no cabalistic reason. Aquaculture producers were quickly able to point out reasons for this downturn, but it has taken

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trend at the beginning of the XXI century. almost 15 years for public administrations and politicians to accept the obvious: red tape and unreasonable licensing time have put the brakes on European aquaculture, while it continues to grow in other parts of the world. The value of EU aquaculture production is presently over â&#x201A;Ź3.8 billion (USD$4.8 billion) with 1.26 million tons of production, mainly mussels (Mytilus spp.), rainbow trout (Onchorynchus mykiss), Atlantic salmon (Salmo salar), oysters (Crassostrea

gigas), gilthead Sea Bream (Sparus aurata) and European Sea Bass (Dicentrarchus labrax). Last year, the European Commission published its Strategic Guidelines for the Sustainable Development of EU aquaculture. This bold document mentions several priority areas that should be addressed in order to unlock the potential of EU aquaculture. First, the simplification of administrative procedures in an industry in which administrative costs and leadtime play an important role in deter-

mining overall competitiveness and development. In several EU Member States authorization procedures take more than 2-3 years to be completed. Secondly, the sustainable development of aquaculture can only be secured through coordinated spatial planning, which is not properly conducted at present, in order to reduce uncertainty and facilitate investment. And third, although the very high environmental, animal health and consumer protection standards that are implemented in EU aquaculture operations should be a positive competitive asset when marketing to European consumers, these standards are a heavy burden for producers, given that 60% of all seafood consumed in Europe is imported and not produced to those same standards. Based on this situation, the EU has placed the development of aquaculture high in its revised Common Fisheries Policy (CFP) agenda for the 2014-2020 period. However, it has been fishery issues, like discards and maximum sustainable yields, which have captured the headlines. Nevertheless, aquaculture is expected to contribute to the preservation of the food production potential on a sustainable basis throughout the Union

to guarantee long-term food security, growth and employment for Union citizens, and to contribute to meeting the growing world demand for aquatic food. As for Governance, the Common Fisheries Policy establishes the creation of a European Aquaculture Advisory Council (AAC) for stakeholder consultation on elements of Union policies which could affect aquaculture. This body will provide advice to the European Commission, to the European Parliament and to Member States. The AAC will take over the role of the prior Advisory Committee for Aquaculture (ACFA) and will broaden the participation of stakeholders for better governance. In order to strengthen the competitiveness of the European aquaculture sector, and for simplification in support of better management of its production and marketing activities, a new Common Market Organization (CMO) for fishery and aquaculture products will try to ensure a level playing field for all aquatic products marketed in the Union - regardless of their origin. This CMO should enable consumers to make better informed choices and support responsible production and

consumption, and should improve the economic knowledge and understanding of Union markets along the supply chain. Finally, the European Maritime and Fisheries Fund (EMFF) will be established to promote a competitive, environmentally sustainable, economically viable and socially responsible fisheries and aquaculture sector. This fund will have at its disposal a €7.4 billion (USD$9.3 billion) budget in current prices for the 20142020 period. Investment in aquaculture, for both private development and collective actions, is perceived as one of the main priorities of the new fund. This financial support will find complementary initiatives in “Horizon 2020,” the biggest EU Research and Innovation program ever undertaken, with nearly €80 billion (USD$100 billion) of funding available over 7 years (2014 to 2020), some of which will be directed towards research in aquaculture. The re-launching of European aquaculture is not assured in the new political scenario, but the signs are positive. Improvements in governance at local and regional levels are still required, but a new era could be starting for aquaculture in the European Union.

Javier Ojeda has been involved in aquaculture production since 1989. He has worked in several fish farms in Spain and Ireland, mainly with gilthead sea bream, European sea bass and Atlantic salmon. He has also worked as an aquaculture consultant and is the general secretary of APROMAR, Spain’s marine aquaculture farmer’s association.

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The Shellfish Corner

I welcome the return of Aquaculture Magazine and I’m grateful to By Michael A. Rice*


r. Chew from the University of Washington, for many years provided news and insightful commentary on shellfisheries and shellfish aquaculture in this column. Ken has been a good mentor to many students, and an excellent researcher and administrator. And, in the traditions of a Land Grant/Sea Grant Extension academic, he has cultivated strong ties with the shellfish aquaculture industry worldwide. In his retirement, Ken has served as the Executive Director of the USDA Western Regional Aquaculture Center and as a Fish & Game Commissioner in his home state of Washington. Addition-

be asked to follow in the rather large shadow of Dr. Kenneth K. Chew ally, he remains active on the Board of Directors of the Pacific Shellfish Institute based in Olympia. Very much in the footsteps of Ken, with this column I hope to approach shellfish aquaculture from a practical viewpoint of sustainable seafood production. This will involve examining scientific approaches for greater economic returns and environmental friendliness, promoting sound public policy and fostering public good will toward shellfish aquaculture in the economy and fabric of coastal communities. Since shellfish farming in most parts of the world occurs in public waters in which governmental agencies are charged with looking

Michael A. Rice with Taylor float trials in Kubeneh Estuary, Gambia 2013. Photo by Emily Nichols.

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out for the public interest, there is by necessity significant interaction with government officials and the public on a variety of issues including food safety, navigation, environmental impacts, and potential conflicts with other users of these waterways. For the last 28 years I’ve been on the faculty of the University of Rhode Island teaching fisheries and aquaculture and conducting research on the physiological ecology of shellfish and the optimization of shellfish aquaculture systems. During those 28 years, I’ve been a founding member and contributor to the regional Extension program of the Northeastern Regional Aquaculture Center, now based at the University of Maryland. This has allowed me to interact with much of the aquaculture industry in our region of the USA. Over the years, I’ve also worked in several countries in Asia and Africa on shellfish aquaculture programs. Locally in my state of Rhode Island, I work closely with the Ocean State Aquaculture Association in solving problems that face this growing industry. In addition to my academic teaching, research and extension programs, I’ve become involved directly in the governmental side of issues through service as a Representative in the Rhode Island state legislature and currently as a member of the Rhode Island Marine Fisheries Council, the body overseeing the state’s fisheries management issues.

Perry Raso is the owner/operator of the Matunuck Oyster Farm in South Kingstown, Rhode Island. To control the growth of Vp and other potential bacterial pathogens, maintenance of a good cold chain from harvest to consumer is a hallmark of his company operation. Photo courtesy of Matunuck Oyster Farm and Oyster Bar.

Research and regulatory communities are taking on a number of pressing issues facing the shellfish industry worldwide. For instance, various diseases and parasites of molluscan shellfish are constantly cropping up and causing problems for producers. Harmful algal blooms (HABs) are a perennial problem requiring shared industry-scientificgovernmental knowledge, understanding and wisdom to manage and overcome problems as they present themselves. Another emerging problem associated with climate change is increased dissolved carbon dioxide in coastal waters, which can cause acidification that ultimately may dissolve the shells of larvae and juveniles of commercially important shellfish. In some areas, the effects of ocean acidification are already being felt by producers and solving the big problems like these will demand a shared industry-scientific-governmental approach. Using this shared approach, traditional water-borne threats to human health have been largely controlled by shellfish sanitation programs in most of the developed world and consumer confidence is high. This confidence in shellfish safety is a prime determinant of market prices, so protecting that consumer confidence is of critical importance. Alarmingly, however, there

is growing concern about the spread of various kinds of Vibrio bacteria into areas without previous problems causing human health problems and affecting the bottom line of shellfish producers. This problem may be in part related to rising seawater temperatures. At issue is that there are reports of small numbers of consumers of raw shellfish becoming ill from a disease-causing form of the bacteria Vibrio parahaemolyticus (Vp) in areas farther north than Vp problems have been experienced in the past. For instance, at the recent NMFS Milford Aquaculture Seminar Laura Wigand of the Washington State Department of Health reported 79 cases of consumers getting ill in 2013 from Vp, possibly associated with commercially harvested oysters in that state. These illnesses in turn led to eight bed closures. And sporadic instances of Vp-related illnesses have been reported along the Eastern seaboard as far north as Maine. Complicating matters is the fact that although Vp and other Vibrio bacteria species are widespread in the environment during warm weather, extremely few stains of the bacteria are actually pathogenic, or capable of causing disease in humans. As a result, actual field testing for the culprit strains is nearly impossible. Research is underway to study the genetics of Vibrio strains and factors that might cause some strains to become pathogenic. The problem of controlling outbreaks of illness associated with Vp in raw shellfish was the main topic of the biennial meeting of the Interstate Shellfish Sanitation Conference (ISSC) held at the end of January this year in San Antonio, Texas. A record 250 shellfish and health professionals, state regulatory agencies, industry representatives, FDA professionals and international program partners gathered to review proposed changes to the ISSC Model Ordinance, the 500 page regulatory “Bible” governing sanitary safety of shellfish sold in the USA. A key proposal of the U.S. Food and Drug Administration (Pro-

posal 13-204) was to mandate the use of ice slurries at the time of harvest to rapidly lower shellfish temperatures and arrest post-harvest propagation of Vp and other bacteria. This proposal was not approved, but it is recognized that getting shellfish cold as soon as practically possible is a key means to prevent outbreaks of illness among consumers. New rules that were adopted at the meeting will add slight costs or burdens to states or business. States will now have to collect timely harvest data to inform risk-per-serving calculations, and mandatory harvester education was upheld. Shellfish industry attendees at the San Antonio meeting have reported an atmosphere of good cooperation and mutual respect among ISSC partners and there is optimism about continued good work into the future. However, industry’s attention to education of the public and keeping their consumers informed about shellfish safety is key to keeping them confident, enthusiastic, and continually coming back to the seafood counter and willing to pay for high quality.

Michael A. Rice, PhD, is a Professor of Fisheries, Animal and Veterinary Science at the University of Rhode Island. He has published extensively in the areas of physiological ecology of mollusks, shellfishery management, molluscan aquaculture, and aquaculture in international development.

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Aquaculture Magazine June / July Volume 40 Number 3  

A Call to Action: Mariculture Could Provide 2/3 of Food Fish Consumption by 2030

Aquaculture Magazine June / July Volume 40 Number 3  

A Call to Action: Mariculture Could Provide 2/3 of Food Fish Consumption by 2030