SHARK NEWS SHARK NEWS 16
NEWSLETTER OF THE IUCN SHARK SPECIALIST GROUP
International trade in white shark Carcharodon carcharias products from New Zealand Clinton Duffy Department of Conservation, New Zealand
The fisheries White sharks Carcharodon carcharias are widely distributed within New Zealand’s exclusive economic zone (EEZ), occurring in coastal and oceanic waters from at least 33oS to 52.5oS, and are taken in a number of non-commercial and commercial fisheries. Recreational
Commercial fisher removing the head of a 4.5m white shark taken in Foveaux Strait, New Zealand. Photo courtesy of Gordon Pyper, Invercargill, New Zealand.
and customary fishers mainly take white sharks as bycatch in gillnets, and occasionally on longlines (Duffy unpubl. data). Sport fisheries for white sharks in New Zealand are largely undeveloped and fishers often tag and release those they do catch (Mossman 1993; Wilson 2002). A protective beach meshing programme run by Dunedin City Council (DCC) operates seasonally off Brighton, St. Clair and St. Kilda beaches. Although targeted, no white sharks have been
OCTOBER 2004
taken since 1975. All sharks taken are disposed of at sea unless requested for research (L. Bell, DCC, pers. comm.). White sharks are not considered capable of sustaining a target fishery in New Zealand and commercial fisheries regulations prohibit directed fisheries (Francis 1998). They are taken as bycatch, however, in bottom-set longline, dropline and gill net fisheries, and occasionally in trawl and tuna longline fisheries (Ministry of Fisheries Catch Effort Database, Duffy unpubl. data). Landings and sale of bycatch is permitted.
Commercial catch Reported commercial landings have averaged only 197kg (s.e. ± 84) green weight per year for the last nine years (Table 1). However, problems with these data include misreporting of fin weight as green weight and non-reporting. For example, in the 1999–2000 fishing year total green weight for fisheries management area (FMA) 3 was the same as the landed weight of fins reported for that FMA (Ministry of Fisheries Catch Effort Database). Problems with the data can also be seen in Table 1 where the reported landings for FMA3 and FMA5 in 1993–94 and 1997–98 respectively are well below the weights of near-term embryos and the smallest known free-living white sharks (Francis 1996). Significant non-reporting is evident when the landings reported in Table 1 are compared to those estimated by the author from media reports, fisher interviews and examination of specimens (Table 2). Weights given in Table 2 were estimated from total length using Compagno’s updated length-weight formula (Compagno 2001). The author's estimate of commercial landings from 1993–94 to 2002– 03, incomplete as it is, is more than 11 times reported landings for the same period (i.e. 20,750kg c.f. 1,797kg; 65 fish c.f. about 15). Nonreporting appears to be particularly bad in FMAs 2, 4 and 8 but may be an artefact of the author's intensive data collection in these areas. A number of factors contribute to non-reporting. Most importantly, fishers are only obliged to record catch and effort data for the five most important species in each set or shot of their gear. As white sharks are relatively uncommon they are unlikely to meet this reporting criterion. Even if a large white shark does make up the bulk of a particular catch fishers are unlikely to regard it as valued part of the catch and therefore record it. Often only the head or jaws are retained. The landed weight will only be reported if the meat and/or fins are landed to a licensed fish receiver, and even then this is dependent on the fisher correctly identifying the shark.
Goods in international trade No data are available on the volume of white shark goods imported and exported from New Zealand. Tariff codes for goods for human consumption are only available for six commercially important chondrichthyan taxa. All remaining chondrichthyans are lumped under a generic code for “other” fishes. There is also only a single code for goods not for human consumption made from fish, and another for collections and collector’s pieces of zoological interest (The Working Tariff Document of New Zealand).
This special issue on CITES also includes ... Shark conservation and management through CITES Spiny dogfish miss the boat Global whale shark tourism
Trade in sawfish rostra Management challenges for freshwater stingrays Shark and ray sanctuary in Mauritania
Shark Specialist Group web site: http://www.flmnh.ufl.edu/fish/organizations/SSG/SSG.htm