6-8 Oct | EEA 2026
Discussion. Collaboration. Action.
Frogfish Photography
POSTERS
Connecting the dots - developing the Basking Shark data directory Harriet Allen¹, Cat Gordon¹ ¹Shark Trust, Plymouth, UK
Citizen science is useful tool for achieving long term and wide-reaching data Harriet Allen collection. However, with multiple regional projects collecting their own data, it can be confusing for those wanting to use this information to know who holds Basking Shark data relevant to their research focus. Due to the existence of different datasets, and potential limitations of data sharing, sightings from one dataset could be misinterpreted as a biological trend, rather than a by-product of social trends and project engagement. This could lead to inferences of regional or temporal declines. Following on from the Basking Shark Forum hosted by the Shark Trust in February 2024, and the enthusiasm that was shared for better connectivity of data, the Shark Trust has been working to develop a Basking Shark Data Directory. This is designed to signpost towards projects and organisations holding data relating to Basking Sharks, including what type of data this represents (e.g. whether sightings, citizen/community science, tracking or photo-ID) and the relevant data owners. This directory only hosts metadata, not the dataset itself. This directory was presented to delegates at the International Conference on Basking Sharks in Galway, Ireland in August 2025, with a workshop facilitated for metadata curation and discussion surrounding logistics and potential future developments. Understanding who holds Basking Shark data, the quantity of data, the geographical and temporal range, and any access restrictions, will help to present a more informed image to researchers, policy makers, and other interested parties. We welcome contributions to this data directory, please see this short form to add your dataset: https://forms.gle/Fzv54vuy2nWtoDUi6 Basking Shark, metadata directory, coordination
Shark skin as a multifunctional armour: linking dermal denticle form to functional performance Rikke Beckmann Dahl¹ ¹Museum of Natural History, Denmark
Sharks are covered by thousands of dermal denticles that show remarkable Rikke Beckmann Dahl morphological diversity across species and ecological niches. While denticles are commonly associated with hydrodynamic drag reduction or mechanical protection, their diversity suggests that there is no single optimal denticle design. Instead, different sharks may require different combinations of functional properties depending on their ecology. Here, we experimentally quantified the functional performance of nine major dermal denticle morphologies across modern sharks. We measured hardness and stiffness using nanoindentation, resistance to mechanical damage through controlled loading, elemental composition and fluorine content as indicators of mineral protection, and hydrodynamic performance using computational fluid dynamics. Denticle morphologies differed strikingly in their functional properties, revealing a broad spectrum of performance rather than a universally superior design. Some morphologies combined high hardness and stiffness with hydrodynamic performance, whereas others showed greater mineral protection and strong resistance to mechanical damage. Surprisingly, denticles from reef-associated and demersal sharks showed relatively low damage resistance, challenging the long-standing assumption that abrasion is a primary driver of their mechanical properties. Deep-water sharks, in contrast, possessed denticles combining high mechanical performance with strongly protective morphologies. Together, our results show that denticle function emerges from both external morphology and internal material properties. Rather than representing variations on a single hydrodynamic design, shark denticles form a multifunctional system in which different combinations of properties may meet the distinct ecological demands faced by different sharks. dermal denticles, functional morphology, biomechanics, ecological adaptation
The Angel Shark Conservation Network Coordinated action for the conservation of Critically Endangered angel sharks Joanna Barker⁶, Àlex Bartolí⁴, Tobias Capel⁶, Nick Dulvy¹, Cat Gordon³, Ali Hood³, Rima Jabado¹, David Jiménez⁵, Eva Meyers² ¹IUCN Shark Specialist Group ²Leibniz Institute for the Analysis of Biodiversity Change ³Shark Trust ⁴SUBMON ⁵University of Las Palmas de Gran Canaria ⁶Zoological Society of London
Tobias Capel
The Angel Shark Conservation Network (ASCN) was established in 2016, to empower action to restore and safeguard angel shark populations throughout their natural range. Focusing to date on the Eastern Atlantic and Mediterranean Sea, encompassing the range of three Critically Endangered angel shark species: Squatina aculeata, S. oculata, and S. squatina. The ASCN aims to facilitate dialogue and information sharing on angel shark conservation efforts and provides a mechanism for developing strategic conservation planning documents at different geographic scales. A number of Action Plans have been developed via multidisciplinary workshops, sitting underneath the Eastern Atlantic and Mediterranean Angel Shark Conservation Strategy. These documents aim to identify the key actions needed to overcome major threats to angel sharks in each specific region to guide future research, management, policy, and conservation. The ASCN actively encourages individuals and organisations to deliver actions outlined in the angel shark conservation planning documents, facilitating a collaborative approach, and working in partnership to support and deliver angel shark conservation. The network has recently formalised its structure, now offering a framework for a variety of interested individuals and organisations to join as Partners, Members or Subscribers. This presentation will showcase priority angel shark actions delivered in the North East Atlantic and Mediterranean Sea by the ASCN Partners and Members – highlighting the importance of collaborative working with key actors across the region. Angel Shark, collaboration, partnership, strategy, conservation
From Rarity to Recurrence? Past and Recent Records of the Bull Ray (Aetomylaeus bovinus) in the Gulf of Trieste and its Interaction with Mussel Farming Saul Ciriaco, Maurizio Spoto, Marco Segarich, Tommaso de Lorenzi, Eleonora Camastra, Edoardo Batistini, Elena Toti, Eleonora de Sabata, Simona Clo
Saul Ciriaco
WWF AMP Miramare Shoreline Soc Coop Medsharks
Aetomylaeus bovinus, the bull ray, is rarely recorded in nearshore waters of the northern Adriatic Sea. In the Gulf of Trieste, previous occurrences were limited to incidental bycatch, with no regular presence documented along the coast. Over the past three years, targeted sightings near mussel farming installations have become more frequent, reported mainly by citizens and other sea users. In 2026, groups of up to 50 individuals were observed feeding on cultured mussels, the largest aggregations recorded for the species in this area. These observations derived not only from reports by mussel farmers and other opportunistic sources, but also from dedicated monitoring along the farms using drone surveys and scuba dives. Loggerhead turtles (Caretta caretta) already feed at the same installations, so the new data indicate mussel farms as a shared food source for different taxa in an area where such presence was previously unusual. It is not yet clear whether this pattern reflects a real increase in local abundance, a change in habitat use, or simply better detection following closer monitoring. We discuss these possibilities and their relevance for the conservation of A. bovinus and for the management of shellfish farming in the Gulf of Trieste. bull ray, mussel farm, Gulf of Trieste
SPiA: Shark Protection in Action Jenny Elliott-Bennett, Teale Phelps Bondaroff, Priyanka Iyer, Usha Ravindra Oceans Asia Zooreach
Jenny Elliott-Bennett In 2018-2019, a shark catch survey was carried out at Bahraini landing sites, fish markets and on board fisher vessels operating in Bahraini waters. 101 fishers of 7 nationalities were interviewed. 14 species of shark and ray were recorded as being caught; these species are on the Red List in the Near Threatened, Vulnerable, Endangered and Critically Endangered categories. Survey results were presented to the Bahrani government and a shark protection law was proposed, written and submitted for legal review. The shark protection plan is being absorbed into a new raft of environment protection laws for Bahrain, to be ratified this year. To make the most of this successful shark protection plan, the project has evolved into SPiA: Shark Protection in Action. SPiA makes available the shark protection law as a framework for other ECOPs, NGOs, governments, indigenous communities to use and take forward in their own locations; to effect policy changes, the adoption of legal instruments, protected species status, reductions in shark catches, stakeholder engagement and conservation outcomes. SPiA is a knowledge-sharing for replication initiative, with appropriate amendments and adaptions to suit each individual location. SPiA has applied for Ocean Decade endorsement. The first collaboration for the SPiA project has begun: Priyanka Iyer and Usha Ravindra of the Zooreach organisation in southern India will attempt to use the framework and adapt it for their specific location and species.
knowledge-sharing, framework
Microplastic ingestion by Neotrygon indica in Eastern Sri Lanka - Baseline assessment and development of a practical methodology for microplastic analysis in elasmobranchs Lize Gijs1, Jana Asselman1, Akshay Tanna2 1
Free University of Brussels (VUB), Blue Growth Research Lab Blue Resources Trust
2
Lize Gijs
Microplastic (MP) ingestion by elasmobranchs remains relatively understudied despite their diverse habitats and feeding strategies. This study established a baseline of MP ingestion in the blue-spotted maskray (Neotrygon indica) from eastern Sri Lanka while developing a practical methodology for MP analysis in elasmobranch gastrointestinal tracts (GITs). The methodology prioritised contamination control, costefficiency, safety and feasibility under limited laboratory conditions. Twenty-four N. indica GITs were collected opportunistically from fisheries landings at three sites between September and November 2025. Samples underwent potassium hydroxide digestion, filtration and density separation, followed by µFTIR analysis of the resulting filters. MPs were detected in 16 of 24 individuals (66.7%), with 186 particles confirmed. Abundance ranged from 0–89 particles per GIT (7.79 ± 18.22). Polyethylene terephthalate (PET) dominated (77.4%), while 64% of particles were <100 µm. No significant relationship was found between body size and MP abundance (ρ = 0.098, p = 0.650). The workflow proved feasible under the available laboratory conditions, but differences in specimen size, feeding ecology and GIT contents indicate that adaptations may be required between species. This study provides baseline data for N. indica in eastern Sri Lanka and an adaptable framework for practical MP analysis in elasmobranchs. gastrointestinal tract, micro-FTIR, marine pollution
A recurrent mortality pattern in Torpedo Rays (Torpedo marmorata) associated with gastric distension in the Canary Islands Gustavo Montero Hernández, Ayoze Castro Alonso, Lucía Caballero Hernández, Eva Montesdeoca Morales, Alicia Velázquez Wallraf, Antonio Fernández Rodríguez, María José Caballero Cansino
Gustavo Montero Hernández
Institute for Animal Health and Food Safety (IUSA), Veterinary School, Universidad de Las Palmas de Gran Canaria (ULPGC)
The torpedo ray (Torpedo marmorata) is a Vulnerable elasmobranch widely distributed in the eastern Atlantic and Mediterranean. This study describes a recurrent clinical and pathological pattern observed in six T. marmorata encountered in the Canary Islands between 2022 and 2025. Specimens originated from Lanzarote and Fuerteventura, with a mean body weight of 4.74 kg and mean total length of 58.6 cm. All animals were encountered alive and showed severe coelomic distension, weakness, positive buoyancy, and marked impairment of swimming and posture. Necropsy revealed large teleosts within the stomachs of all six specimens. The prey were largely undigested, with a mean length of 28.4 cm, and were associated with marked gastric distension. No other major macroscopic findings were identified that could readily explain the clinical presentation. The recurrent occurrence of large, poorly digested prey together with severe gastric distension and altered buoyancy suggests an association between ingestion of large prey and impaired locomotion. Gastric distension may interfere with normal body posture and swimming performance, potentially increasing the vulnerability of affected animals to stranding and mortality. These findings provide new information on a recurrent clinical and pathological presentation in T. marmorata in the Canary Islands and highlight the need for further investigation into the potential role of feeding-related gastrointestinal distension in torpedo rays. pathology, Torpedo marmorata, Canary Islands
Hepatic cholangiocarcinoma with splenic metastasis in a wild Angelshark (Squatina squatina): histopathological and ultrastructural Findings Gustavo Montero Hernández1, Ayoze Castro Alonso1, Gustavo A. Ramírez2, Antonio Espinosa de los Monteros1, Alicia Velázquez Wallraf1, Lucía Caballero Hernández1 , Eva Montesdeoca Morales1, Antonio Fernández1, María José Caballero1
Gustavo Montero Hernández
1
Institute for Animal Health and Food Safety (IUSA), Veterinary School, Universidad de Las Palmas de Gran Canaria (ULPGC), Las Palmas, Spain 2 Department Ciència Animal, Universitat de Lleida, Lleida, Spain
The Angelshark (Squatina squatina) is a Critically Endangered elasmobranch whose diseases remain poorly documented in the wild. An adult male (108 cm total length, 9.3 kg) was found dead stranded at Playa Guasimeta, Lanzarote (Canary Islands, Spain). Necropsy revealed a hepatic nodule (0.5 cm) and multiple similar splenic nodules (0.5–1.2 cm), with additional coalescing lesions on the visceral surface. Histologically, the hepatic lesion consisted of an infiltrative epithelial neoplasm composed of cuboidal to polygonal cells arranged in irregular ductular, tubular and anastomosing gland-like structures supported by fibrovascular stroma. Multifocal coagulative necrosis was observed. Splenic lesions showed identical histomorphological features, supporting metastatic dissemination. Based on lesion distribution and histomorphology, a diagnosis of hepatic cholangiocarcinoma with splenic metastasis was established. Immunohistochemistry using hepatocellular, biliary and epithelial markers did not provide diagnostically useful immunoreactivity. Transmission electron microscopy demonstrated clear epithelial differentiation, with abundant cytoplasmic tonofilaments and well-developed desmosomal junctions, providing complementary ultrastructural evidence. This first report of metastatic cholangiocarcinoma in S. squatina expands the pathological baseline for a Critically Endangered elasmobranch and provides novel insight into tumor behaviour in this poorly characterized species. pathology, neoplasia, Squatina squatina
Pathological Assessment and Causes of Death in Stranded Elasmobranchs from the Canary Islands (2022–2026) Gustavo Montero Hernández, Ayoze Castro Alonso, Lucía Caballero Hernández, Eva Montesdeoca Morales, Alicia Velázquez Wallraf, Ángel Curros Moreno, Cristian Suárez Santana, Antonio Fernández, María José Caballero
Gustavo Montero Hernández
Institute for Animal Health and Food Safety (IUSA), Veterinary School, Universidad de Las Palmas de Gran Canaria (ULPGC), Las Palmas, Spain
Since 2022, the Fish Pathology Unit of the Institute of Animal Health and Food Safety (ULPGC) has conducted necropsies of 122 stranded elasmobranchs along the Canary Islands within the Canarian Network for Wildlife Health Surveillance (Red Vigía Canarias). The specimens comprised 76 angelsharks (Squatina squatina), 10 smooth hammerhead sharks (Sphyrna zygaena), 8 spiny butterfly rays (Gymnura altavela), 7 marbled torpedo rays (Torpedo marmorata), 5 Myliobatis aquila, 5 Dasyatis pastinaca, 2 Galeorhinus galeus, and 9 individuals representing additional species. Females accounted for 53.8% and males for 46.2%. Carcass condition was classified as very fresh (7.8%), fresh (6.1%), early decomposition (27.8%), advanced decomposition (36.5%), or severe decomposition (21.7%). Causes of death were classified as natural (45.5%), anthropogenic (25.6%), or undetermined (28.9%), with undetermined cases mainly associated with advanced or severe decomposition. The high proportion of decomposed carcasses highlights the importance of carcass condition when interpreting pathological findings and assigning cause of death. Systematic necropsy and pathological assessment provide valuable baseline information on mortality in Canary Island elasmobranchs. Furthermore, the programme has established a tissue bank supporting anatomical, histological, pathological, and forensic research, providing a valuable resource for future health surveillance and conservation studies. pathology, Canary Islands, necropsy
Pathological assessment of commercially important elasmobranchs from the Cantabrian Sea: a baseline for health surveillance Lucía del Carmen Caballero-Hernández1 1
Institute of Animal Health and Food Safety (IUSA), University of Las Palmas de Gran Canaria (ULPGC)
The health status of commercially exploited elasmobranchs remains poorly characterized despite their ecological and fisheries importance. Pathological surveillance can provide valuable information on the occurrence of infectious, parasitic and non-infectious conditions in wild populations. The Shark-Ray Map project aims to establish a pathological baseline for commercially important elasmobranchs from the Cantabrian Sea through systematic necropsy and histological examination. Between January and June 2025, complete necropsies were performed on 47 specimens: 34 sharks (Scyliorhinus stellaris, Galeorhinus galeus and Prionace glauca) and 13 undulate rays (Raja undulata). Mean total length and body weight were 79.9 cm/2.21 kg, 144.4 cm/13.07 kg, 149.7 cm/10.79 kg and 74.5 cm/3.43 kg, respectively. Parasites were the most frequent finding, detected in 34.04% of specimens, mainly nematodes affecting the digestive tract and gills. Most parasitic infections were not associated with relevant histopathological lesions, although granulomas related to parasite migration were observed. Multifocal calcifications occurred in 19.15% of specimens, while circulatory alterations were detected in 12.77%. These findings provide a pathological baseline for commercially important elasmobranchs from the Cantabrian Sea and highlight the value of systematic pathological assessment for detecting relevant pathological conditions and improving health surveillance of fisheries-derived elasmobranchs. pathology, histology, fishery
The electrosensory system of elasmobranchs from the Canary Islands: morphological diversity and a baseline for future environmental assessment Lucía del Carmen Caballero-Hernández1 1
Institute of Animal Health and Food Safety (IUSA), University of Las Palmas de Gran Canaria (ULPGC)
The ampullae of Lorenzini are a specialized electrosensory system that enables elasmobranchs to detect weak electric fields involved in prey detection and orientation. This study characterized the morphology, pore distribution and histological organization of the ampullary system in seven elasmobranch species from the Canary Islands: five sharks, Sphyrna zygaena, Sphyrna lewini, Mustelus mustelus, Centroscymnus coelolepis and Centroscymnus owstonii, and two rays, Dasyatis pastinaca and Taeniurops grabatus. Heads were stained with 0.02% methylene blue, and pore distribution was quantified using image analysis. Histological sections were examined to characterize the ampullary system. Marked interspecific differences were observed in pore abundance and spatial distribution. Counts ranged from 775 pores in C. coelolepis to 1.988 in M. mustelus, which showed a pronounced ventral predominance, whereas S. zygaena displayed a predominantly dorsal distribution. Batoids showed high pore numbers distributed across the head and towards the pectoral fins, revealing a distinctive organization compared with sharks. Histologically, all species showed the characteristic ampullary organization, while T. grabatus presented a distinctive thick connective tissue layer around the canals. These results provide species-specific baseline data for Canary Island elasmobranchs and may support assessment of anthropogenic pressures, including offshore marine infrastructure, on the electrosensory system. lorenzini ampullae, morphology, electroreception
Vertebral age estimation in elasmobranchs: species-specific variability, methodological effects and observer uncertainty Lucía del Carmen Caballero-Hernández Institute of Animal Health and Food Safety (IUSA), University of Las Palmas de Gran Canaria (ULPGC)
Age estimation is essential for understanding elasmobranch population dynamics, but vertebral band interpretation may vary among species, visualization methods and observers. We evaluated age estimation in 47 individuals of Galeorhinus galeus (n=15), Scyliorhinus stellaris (n=10), Prionace glauca (n=9) and Raja undulata (n=13). Theoretical ages were derived from body length using the inverse von Bertalanffy function. Vertebrae were examined unstained and after crystal violet and silver nitrate staining. Agreement was assessed by Bland–Altman analysis, while estimation error and inter-observer variability were evaluated using Mean Absolute Error (MAE) and coefficients of variation. Vertebral ages tended to be underestimated in G. galeus, S. stellaris and R. undulata, whereas P. glauca showed closer agreement with length-derived ages. Visualization method affected estimates, with significant differences between crystal violet and unstained vertebrae, while crystal violet and silver nitrate did not differ significantly. Observer variability was substantial, with coefficients of variation of 30.81% to 53.51%. These findings demonstrate substantial species-specific variability in vertebral age estimation and show that both visualization method and observer interpretation contribute to variability in age estimates. The results support the need for species-specific validation of vertebral ageing methods and standardized criteria. ageing, vertebrae, methodology
Sharing the waters: behavioural responses of juvenile smooth hammerhead sharks (Sphyrna zygaena) to snorkel tourism and provisioning in an Azorean nursery Linn Mansson1 1
Okeanos - Institute of Marine Science, University of the Azores
Linn Mansson
Considering the rapid decline of shark populations globally, protecting essential habitats such as nurseries is an important step in shark conservation. Off the coast of Faial Island in the Azores, juvenile smooth hammerhead sharks aggregate regularly in surface waters during summer in a well identified nursery area. The easy and reliable access to the nursery has led tourism operators to start offering commercial snorkelling trips, as the first place in Europe where tourists can book this activity. Despite providing both economic potential for the region and educational potential about the species, scientific data of the anthropogenic impact on the juvenile sharks are largely missing. We used Unmanned Aerial Vehicle to collect behavioural data of smooth hammerhead in the aggregations off Faial Island, during summer 2026. Their behaviour was collected in relation to four treatments: 1) Control (no humans or bait provisioning); 2) Stressor only (snorkelers); 3) Attractor only (bait provisioning); 4) Stressor and attractor (snorkelers & bait provisioning). This study thus aims to assess the impact of shark-tourism by quantifying energetic proxies and movements in a before-and-after-control-impact experimental design using computer vision YOLO models in TRex. The resulting information could further be used when constructing a code-of-conduct for shark-diving tourism activities and informing management strategies towards a sustainable tourism. shark nursery, ecotourism, UAV monitoring
Optimizing BRUV surveys in the deep sea: lessons learned from a case study in the Azores 1
Judit Nieto Martín, Diana Catarino1, Pau Robles1, Jade Guérillon1, Eva Giacomello1,2, Gabriel Gonçalves1, Laurence Fauconnet1 1
Okeanos - Institute of Marine Sciences, University of the Azores IMAR - Instituto do Mar, Azores
2
Judit Nieto Martín
While BRUVs have long been used to study sharks, their application in the deep sea remains scarce and limited, and not always the same procedures apply. In the Azores, Portugal, research efforts have been developed in the recent years to deploy deep-sea BRUVs, with the objectives to test the effectiveness of this non-invasive tool to monitor deep-water sharks elasmobranch and to study their behavior in different contexts. While working in the deep sea creates additional challenges, they provide valuable insights into these little-known data-poor species. Over 150 BRUVs videos, totaling 500 hours of bottom recording time, have now been collected enabling us to observe 18 species of deep-sea sharks, 3 rays, and 2 chimeras in their natural habitat. For some species that are not, or rarely, caught by local fishing gears and scientific surveys, BRUVs provide invaluable information on their distribution and relative abundance. Deployments also allowed us to find the nursery area of one rare deep-water shark species. The current ongoing work aims at testing AI tools to fasten and ease the processing of BRUV videos. This presentation will explain these progress, main achievements and best guidelines identified to use BRUVs in the deep sea. deep-sea BRUVs, best guidelines, elasmobranchs
Drivers of relative abundance of coastal sharks recorded on baited remote underwater videos (BRUVs) in the Cayman Islands, Western Caribbean Agathe Moreau1,2, Dr Johanna K. Kohler1 1
Cayman Islands Department of Environment Université Côte d’Azur
2
Agathe Moreau
Understanding the drivers of shark relative abundance is essential to inform effective shark conservation. In the Cayman Islands, the ecological drivers of coastal sharks remain unidentified despite long-term monitoring. This study investigated the drivers of relative abundance for the Caribbean reef shark Carcharhinus perezi and Atlantic nurse shark Ginglymostoma cirratum using baited remote underwater videos (BRUVs, n = 562) and generalised linear models on data from 2015–2018. Findings revealed that (1) both species pointed towards higher abundance outside Marine Protected Areas (MPAs), (2) C. perezi relative abundance increased with depth around both islands, while G. cirratum increased with depth in Grand Cayman but was not influenced by depth in Little Cayman, (3) C. perezi relative abundance varied across years and increased with fish species richness, while G. cirratum was significantly higher in summer, on non-reef coastal habitats, and increased with fish biomass in Little Cayman. The results suggest that (1) both species may range beyond protected areas, (2) anthropogenic disturbances may influence responses, particularly in Grand Cayman, and (3) seasonal, habitat and prey availability influence species differently. The findings emphasise the need for island and species-specific conservation measures, for the holistic protection of sharks and their prey communities and habitats, and for the assessment of anthropogenic impacts on sharks in Cayman’s coastal waters. shark relative abundance, ecological drivers, Marine Protected Areas (MPAs)
Comparing sensory deterrents as a bycatch reduction method for Raja clavata: a behavioural analysis Kaat Paepen, Sven Sebastian Uhlmann, Enya Kvaratan 1
Vrije Universiteit Brussel Flanders Research Institute for Agriculture, Fisheries and Food
2
Kaat Paepen Elasmobranchs are negatively impacted by the fishing industry, as they are often caught incidentally as bycatch. In Belgium, the most economically valuable species are common sole and European plaice which are caught mainly by beam trawling. This non-selective fishing method leads to high numbers of bycatch. Several bycatch reduction methods have been tested, but due to the similar size and shape of elasmobranchs, specifically rays, it is difficult to mitigate capture of endangered, threatened and protected elasmobranchs without economic losses. Investigations into sensory deterrent devices are emerging since elasmobranchs can detect weak electromagnetic fields with specialized pores: Ampulla of Lorenzini. In this study, the repellent capacity of two deterrent devices Sharkbanz® Zeppelin, a rare-earth magnet and Fishtek Marine Sport® Sharkguard, a device emitting electrical stimuli, was evaluated on juvenile Raja clavata. For both devices a significant reduction in passage rate was found indicating the possibility of a repellent effect. There was no significant difference in bait avoidance probability between active device and placebo treatments. However, estimations on behavioural duration and probability of occurrence suggested that the electrical deterrence of the SharkGuard was slightly more suited for repelling R. clavata. Overall, devices seemed to have immobilized animals rather than triggering a flight or evasion reaction when approaching the active devices.
electroreception, bycatch reduction, behaviour
From hooks to DNA: exploring Cape Verdean shark diversity through sport fishing and citizen science Chiara Pani, Simone Di Crescenzo1,2, Simone Maresca3, Marco Martinez4, Antonio Pucci5, Umberto Scacco4, Rita Cannas1 1
Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy National Interuniversity Consortium for Marine Science (CoNISMa), Rome, Italy 3 Department of Sciences, Roma Tre University, Rome, Italy 4 Italian Institute for Environmental Protection and Research (ISPRA), Rome, Italy 5 Department of Ecological and Biological Sciences, Tuscia University, Civitavecchia, Italy 2
Chiara Pani
Effective fisheries management and conservation rely on accurate species identification, particularly for taxa vulnerable to exploitation and bycatch. Cabo Verde hosts a remarkably diverse shark assemblage, with over 50 species recorded, nearly two-thirds of which are threatened. Despite its importance for chondrichthyan conservation, recent information on local shark diversity remains limited. In the present study, we applied a DNA barcoding approach to identify shark specimens caught on Boa Vista (Cape Verde) during a sport fishing trip by using mitochondrial DNA markers. In particular, we produced new molecular data for 4 putative species present in the area, morphologically identified as Carcharhinus brevipinna (Müller & Henle, 1839), Carcharhinus limbatus (Valenciennes, 1839), Paragaleus pectoralis (Garman, 1906), and Rhizoprionodon acutus (Rüppell, 1837). Furthermore, tissue samples were collected from fins and jaws retrieved in local shops and fish markets and then analysed to identify them at the species level. According to preliminary morphological identification, fins and jaws belong to at least six different genera (Carcharhinus, Galeocerdo, Isurus, Negaprion, Rhizoprionodon, Sphyrna) recorded in the area. This study expands the molecular data available on Cape Verdean sharks by providing new sequences for endangered species and their local populations, many of which have little genetic data available for the Cape Verdean archipelago. Cabo Verde, sharks, conservation
Mapping the global distribution of oviparous Chondrichthyes: identifying hotspots and conservation priority areas Rhiannon Plant1 1
Bangor University
Rhiannon Plant
One third of chondrichthyes are at risk of extinction. Around 40% are oviparous and lay eggs in spatially discrete egg nurseries. However, their global distribution remains poorly understood. This study presents the first global analysis of the distribution of oviparous chondrichthyes, identifying areas of high biodiversity to aid future research and conservation. Spatial data was obtained from the IUCN and global patterns in species richness, threatened species richness, rarity-weighted richness, and taxonomic distinctness were analysed and compared among taxonomic groups and across depth zones. Overlap with fully no-take Marine Protected Areas (MPAs) was assessed. Overall findings were that oviparous chondrichthyes occurred along continental margins with only 6% found deeper than 3000m. Distribution patterns were spatially hetergenous and hotspots were distinct to those of non-oviparous chondrichthyes. Hotspots were not spatially congruent between biodiversity measures or across taxonomic groups. This indicates that species richness alone is insufficient in determining all areas of potential importance for these species and hotspots are taxa-specific meaning important areas could be obscured when aggregating groups. Less than 1% of the total range of threatened oviparous chondrichthyans overlapped with fully no-take MPAs, highlighting gaps in strict protection against fishing pressure. Chondrichthyes, oviparity, biodiversity hotspots, egg nurseries
Communicating regulations to support sustainable fisheries: Shark Trust Fisheries Advisories for regional fisheries management organisations Jack Renwick1, Ali Hood1 1
Shark Trust, Plymouth, UK
Jack Renwick
Elasmobranchs are encountered by mixed and directed fisheries on a global scale. The Shark Trust has produced commercial Fisheries Advisories for the fishing industry and enforcement agencies since 2010. The Trust engaging with fisheries enforcement agencies and the fishing industry to provide materials and advice supports and promotes sustainable fisheries. Until now, while available in several languages, these advisories were exclusively designed to give rapid access to the current legislative status of sharks, skates, and rays for UK and EU vessels in the Northeast Atlantic. This year, we have developed Fisheries Advisories for the International Commission for the Conservation of Atlantic Tunas (ICCAT). This Regional Fisheries Management Organisation (RFMO) is responsible for the management and conservation of tuna and tuna-like species (including sharks) in the Atlantic Ocean. Oceanic sharks are encountered by fishing vessels in the high seas of the Atlantic, and many of these species are exceptionally threatened by overfishing. Within the management framework of ICCAT, some shark species are prohibited to target and retain, whereas other species can be caught and sold, with a range of different management measures in place. A need for Fisheries Advisories has been identified in this context; to enable fishers and managers to quickly and easily determine which management measures apply to which species, and in which hemisphere. This poster will showcase the ICCAT Fisheries Advisories, their development, and how they can help to achieve sustainable fisheries. Working in partnership with RFMOs, we will continue to create more Fisheries Advisories for additional areas. bycatch, discards, fisheries
Catch and discard reporting: addressing shortfalls for elasmobranchs Jack Renwick1 1
Shark Trust, Plymouth, UK
The challenges for shark and ray populations are intrinsically linked to the strength of the fishing industry and the often inadequate and inconsistent approaches to fisheries management. Overfishing is driving a third of shark species toward extinction (Dulvy et al., 2021).
Jack Renwick
Comprehensive fisheries management is required to prevent overfishing of elasmobranchs. Achieving widespread compliance with legislation, regulations, and management is challenging for regulatory bodies. Poor compliance undermines the effectiveness of management measures, and widescale failures to adhere to mandatory bycatch and discard recording requirements are key limitations to informed decision making. This presentation will showcase the Shark Trust’s project to unpack and address the barriers to achieving accurate catch and discard recording and reporting in fisheries where elasmobranchs are caught. The outcomes of the Sharks International Workshop “Overcoming Challenges to Achieving Compliance with Fisheries Legislation” will be included in this presentation, outlining the findings that relate to catch and discard recording legislation. As part of this project, we have engaged with fishing industry representatives and government practitioners, exploring the challenges faced in different fisheries under varying management conditions. The desired outcome of this project is to gather possible solutions and identify methods to overcome the recognised challenges in achieving compliance, and determine how global practitioners can assist each other in this endeavour. These results will be used to advocate for better fisheries management for elasmobranchs. fisheries, sustainable management, communication
An oceanic archipelago with potentially key habitat for four mobulid ray species in the Eastern Atlantic Alicia Rodríguez Juncá1 1
Universidad de la Laguna, Canary Islands, Spain
Despite ongoing direct and indirect fishing pressures across the West Alicia Rodríguez Juncá African coastline, knowledge of manta and devil rays (mobulids) in the Eastern Atlantic remains limited. As highly mobile species, these vulnerable elasmobranchs are difficult to study; however, aggregations associated with oceanic archipelagos provide unique opportunities for research. Here, we synthesize evidence on reproductive activity and life-history stages of 4 mobulid species in the Canary Islands using historical records and citizen science observations. Pregnant females were recorded for Mobula tarapacana (n=26) and M. birostris (n=1). Healed mating scars were observed in M. tarapacana, consistently on the right pectoral fin, and fresh mating wounds in M. mobular, indicating recent copulation events. Courtship behaviour of M. mobular was directly observed (n=3). Early life-history stages were also recorded, with juveniles of M. birostris (n=15) and M. thurstoni (n=4). Large aggregations were documented, reaching up to 56 M. tarapacana and 18 M. thurstoni individuals. The cooccurrence of juveniles, pregnant females, mating-related evidence and aggregations suggests that the Canary Islands support multiple phases of the mobulid life cycle. This oceanic archipelago may function as a refuge within the distribution range of these species, providing a potential oasis in offshore waters exposed to fishing pressure and highlighting its importance for the conservation of mobulids in the Eastern Atlantic. Mobula, reproductive ecology, Canary Islands
Joining forces for Angelsharks: tracking and satelite tagging Squatina squatina in a unique hotspot in Greece Nikoletta Sidiropoulou1, Kalliopi Lazarou1, Martina Ciprian1, Eva K.M Meyers2,4, David Jimenez Alvaro3,4, Tomas Baneras3,4, Pablo Villafranca4, Ioannis Giovos1 1
iSea Environmental Organisation for the Preservation of the Aquatic Ecosystems, Kritis 12, 54645, Thessaloniki LIB,Museum Koenig Bonn, Leibniz Institute for the Analysis of Biodiversity Change, Bonn, Germany 3 IU-ECOAQUA, Universidad de Las Palmas de Gran Canaria, Las Palmas, Spain 4 Angel Shark Project, Islas Canarias, Spain 2
Angelsharks (Squatina spp.) are among the most threatened shark families worldwide, with all three Mediterranean species listed as Critically Endangered by the IUCN Red List. In June 2026, Angel Shark Project (ASP) Greece and ASP Canary Islands joined forces on Lemnos Island for a ten day campaign implemented under the 5-year ELSP project "Reviving Lemnos," aiming to expand knowledge of angelsharks around Lemnos, a recently identified key area for the species, while also launching a new Shark Conservation Fund project on angelshark conservation in Greece and the Canary Islands. A multi-method survey combined specialised training in adult satellite tagging, applied to individuals incidentally caught as bycatch by local fishers, with underwater visual censuses, BRUVS deployment, and night snorkelling surveys on sandy beaches targeting potential nursery areas. The first individual, a 90 cm female caught as bycatch over Posidonia oceanica meadows at 20 m depth, was fitted with a LOTEK PSATFLEX pop-up satellite tag (4 month duration), the first shark satellite tagging in Greek waters and one of the few conducted for the species globally. Four further deployments are scheduled, with tag durations of 6 to 12 months. Satellite tracking, combined with visual census and fisheries monitoring data, will inform movement patterns and habitat use around Lemnos, supporting conservation of one of the Mediterranean's most threatened sharks. angelshark, Squatina squatina, satellite tagging
Bridging science and community: the first specieslevel elasmobranch landings baseline for Angola Ana Lúcia Furtado Soares, Rima W. Jabado, Carmen van-Dúnem dos Santos Ludwig-Maximilians-Universität München, Munich, Germany Angola Elasmo Project IUCN SSC SSG, Elasmo Project, P.O. Box 29588, Dubai United Universidade Agostinho Neto, Faculty of Sciences, Av. 4 de Fevereiro 71, Luanda, Angola
Ana Lúcia Furtado Soares
The Eastern Central Atlantic sustains intensive, poorly documented elasmobranch fisheries, and regional populations have declined since the 1970s. Angola remained a conspicuous gap: no species-level landings data existed on its coast, precluding assessment, national listing and evidence-based management. The Angola Elasmo Project was established to close this gap, building the first landings baseline jointly with the communities that depend on the resource. We monitored three landing sites in Namibe Province over five survey periods, 2021–2025. Cooperative members granted access to the catch and Angolan students were trained to collect data. Some 50,000 elasmobranchs were enumerated, 13,485 measured for length, sex, maturity and gear, and 83 fishers interviewed. Twenty-eight species were recorded, 64% threatened on the IUCN Red List. Three taxa comprised 53% of individuals, led by Mustelus mustelus (22%) and Squatina oculata (16%). Most individuals were immature at capture; gravid females occurred in 13 species (n = 1,209), with parturition-associated landings beginning in September and rising from 2023 to 2025. Squatina oculata, considered possibly extirpated in Angola, was recorded regularly with yolk-sac neonates. We recommend a precautionary September–December closure, locally calibrated size limits, and national listing of Critically Endangered species. Sustained sampling and local acceptance both depended on returning data to the cooperatives and training in-country. participatory monitoring, Squatina oculata, Eastern Central Atlantic
Transforming citizen observations into conservation data: RedPROMAR, a standardized monitoring platform for elasmobranchs Héctor Toledo-Padilla1 1
RedPROMAR, Gobierno de Canarias
Héctor Toledo-Padilla
Reliable information on elasmobranch populations remains a major challenge for conservation, particularly in oceanic regions where conventional monitoring is spatially and temporally limited. The Canary Islands Marine Observer Network (RedPROMAR), promoted by the Government of the Canary Islands, provides a standardized citizen science framework for collecting, validating and analysing marine biodiversity observations. Species-specific reporting forms, standardized metadata, photographic evidence and expert validation transform opportunistic sightings into robust biodiversity data. The platform currently contains more than 6,000 elasmobranch records, including over 600 standardized shark and ray observations collected through the dedicated Elasmobranch Monitoring in the Canary Archipelago project. These data have improved knowledge of species distributions, identified recurrent occurrence areas for different life stages, documented incidental captures, supported the confidential management of sensitive locations, and contributed to monitoring protected species and detecting distributional changes. This case study demonstrates that standardized citizen science can generate high-quality ecological datasets that complement conventional monitoring while providing evidence to support research, spatial conservation planning and the adaptive management of threatened elasmobranch populations in the Canary Islands. marine biodiversity, data validation, participatory research
Non-invasive visual assessment of body condition in blue sharks from the northwestern Mediterranean Alejandra Lopez Valentin1 1
Sotamar Shark Research Association
The blue shark is one of the main pelagic predators in the Mediterranean Sea. Alejandra Lopez Valentin This shark has experienced a severe decline, being listed as critically endangered by the IUCN. Assessing the body condition (BC) of individuals is essential to evaluate the potential effects of the factors driving this decline. In this study, BC was assessed in wild blue sharks using non-invasive underwater image analysis. Between 2022 and 2025, 230 shark sightings were recorded. 131 of these were selected for morphometric analysis after they presented whole animal suitable images. Total length (TL, in meters) was measured in each case using a dual-laser photogrammetry system. Twelve body measurements (6 lengths including TL, 2 heights and 4 widths) were obtained from lateral, ventral and dorsal photographs in pixels, and subsequently converted into metric units considering TL. Several biometric ratios were calculated, and the most robust and practical indices were selected. These indices were used to compare apparently healthy sharks with individuals showing injuries or parasite infestations, testing the hypothesis that affected sharks would exhibit lower BC. This study provides new insights into the potential impact of sublethal stressors on blue sharks, contributes to the development of non-invasive tools for monitoring the BC and health of wild pelagic sharks, and lays the basis for the next coming automatized BC assessment system. Blue Shark, body condition, photogrammetry
Population genomics of the spinytail skate (Bathyraja spinicauda) in the Northeast Atlantic Rosalinde van Ooijen1 1
Institute of Marine Research Norway
Many elasmobranchs have K-selected life-history traits, such as slow Rosalinde van Ooijen growth, late maturity and low reproductive rate, making them vulnerable to overfishing and climate change. Deep-sea skates are an understudied group within elasmobranchs; although historically inaccessible to most fisheries, fishing efforts are expanding into deeper waters, further endangering them. The spinytail skate (Bathyraja spinicauda) is Near Threatened, with a suspected population reduction of 20–29% over the last 70 years. Knowledge of population structure is necessary for conservation, particularly given the role of skates in deep-sea ecosystem functioning. Individuals were sampled along the coasts of Norway and Greenland and in the Barents Sea between 2010 and 2023 through bottom trawling research cruises. Single-nucleotide polymorphisms (SNPs) were used to assess population structure, and a seascape genomics approach was applied to identify loci potentially under environmental selection. Bayesian clustering and DAPC analysis of 4302 SNPs from 30 individuals revealed two distinct genetic clusters, separating Greenland skates from Norwegian skates. Some substructure was also observed between the Norwegian Continental Slope and the Barents Sea. Four loci were associated with environmental variables including current velocity and dissolved oxygen. Future research should include samples from the Faroe Islands to broaden understanding of population structure across the North Atlantic. seascape genomics, deep-sea skates, conservation
Mediterranean smoothounds: little-known threatened shark species potentially effective predators against the invasive blue crabs Nicolas Ziani1, Terry Carbon1, Nithika K P1, Marceau Begon1, Mathis Bernard1, Elina Bouchet1, Benjamin Laforet1, Alessandro De Maddalena2, Patrick L. Jambura3, Hakan Kabasakal4 1
Groupe Phocéen d'Étude des Requins (GPER) , 118 rue du Rouet 13008 Marseille, France, Shark Museum, Simon’s Town, Cape Town, South Africa 3 University of Vienna, Department of Paleontology, Austria 4 Hydrobiological Research Association, Gökçeada, Çanakkale, Türkiye 2
Three species of the genus Mustelus are known in the Mediterranean Sea: M. asterias, M. mustelus and M. punctulatus. Despite the research effort spent in past decades, still several gaps are present in the current knowledge of their life history. Regional bycatch of these species poses a severe threat to Mediterranean populations. Mustelus. spp. is a durophagous mesopredator that is specialized preying especially on crustaceans. We report preliminary evidence of Mustelus spp. feeding on the blue crab Callinectes sapidus in Corsican waters, suggesting a potential regulatory role on this invasive crustacean. Based on direct field observations and photographic/video evidence from Corsican waters, individuals of Mustelus spp. were observed consuming C. sapidus, providing the first preliminary evidence of predation. The high fecundity of the smoothhounds could represent a strong advantage for the resilience of the declined populations. Our observations highlight the importance of conserving Mediterranean smoothhound populations. Although the available evidence is preliminary, predation on C. sapidus suggests that healthy smoothhound populations may contribute to the natural regulation of invasive blue crab populations and potentially mitigate their ecological impacts in Mediterranean coastal ecosystems. Beyond their conservation value, these observations emphasize the potential functional importance of smoothhounds as native predators within Mediterranean coastal food webs. Smoothounds, predator, invasive blue crab
New unpublished specimens of great white sharks historically recorded in the north-western Mediterranean (France) Nicolas Ziani1, Marceau Begon1, Elina Bouchet1, Nans Vidal1, Sophie Guibert1, Benjamin Laforet1, Mathis Bernard1, Titouan Piaumier1, Nithika K P1, Terry Carbon1 1
Groupe Phocéen d'Étude des Requins, 118 rue du Rouet 13008 Marseille, France
The great white shark, Carcharodon carcharias (Linnaeus, 1758) (Lamniformes: Lamnidae), is one of the largest species of coastal and oceanic macro-predatory sharks. Six genetically distinct and geographically isolated philopatric populations have been identified worldwide: Australian, South African, Northwest Atlantic, Northeast Pacific, Japanese, and Mediterranean. The Mediterranean population is identified as genetically distinct. C. carcharias has been categorised as vulnerable in the Mediterranean since 1996 and is currently classified as critically endangered (CR, IUCN). Data on the global population size of the great white shark are insufficient, and only approximate estimates are available for the conservation of this species in dangerous decline. The historical census of the species indicates that 789 records of its presence have been documented across the Mediterranean to date. Historically, the species has been recorded only sporadically in the Gulf of Lion since the 16th century. Here we report new historical specimens for 2026, consisting of complete sets of jaws and their measurements, as well as unpublished reports from French municipal archives describing new specimens that were previously unknown or poorly documented. White Shark, unpublished historical data, Gulf of Lions
Microplastics: beyond the gut Where the questions begin Kelsey-Michelle O'Shaughnessy1 1
Newquay University Centre
Microplastic pollution is now recognised as a global threat to marine ecosystems, yet our understanding of what happens after ingestion remains limited, particularly in sharks. This short documentary follows the journey of an undergraduate research project investigating suspected microplastic occurrence in the stomach and liver of the small-spotted catshark (Scyliorhinus canicula) from southwest England. Combining laboratory methods and microscopy with cinematic storytelling, the film explores how 28 suspected microplastics were recovered from shark tissues, with particles detected in 22.2% of liver samples in the first known assessment of hepatic occurrence in this species, raising questions that extend beyond ingestion alone. Rather than focusing solely on results, the documentary places the research within the wider context of contaminant accumulation, fisheries, consumer awareness, and the importance of understanding how pollutants move through marine food webs. By combining accessible science communication with original research, Beyond the Gut demonstrates how undergraduate research can contribute to emerging questions in marine pollution while encouraging audiences to think differently about the hidden pathways of microplastic contamination and why they matter for sharks, marine ecosystems, and the people who depend on them. Elasmobranchs, microplastics, ecotoxicology