Sophy R. McCully Phillips

At the inception of the ICES Journal of Marine Science, first published in 1926, elasmobranchs were largely peripheral to fisheries science. Beyond a few commercially valuable species such as basking shark and spurdog, knowledge of occurrence, life history, population structure, and trends of the ∼105 elasmobranch species occurring across the ICES area was limited. This is reflected in the fact that the first elasmobranch-focused paper in the Journal was published by Holden and Meadows in 1964. However, as commercial fisheries expanded and population declines and local extirpations were documented in the late 20th century, elasmobranchs gained increasing attention from both commercial and conservation perspectives. The ICES Working Group for Elasmobranch Fishes, established in 2003, pioneered methods for estimating removals and stock status despite significant data limitations. From issuing the first advice sheets for six “stocks” in 2005, the group now provides assessments for 56 stocks—more than any other ICES assessment group. This review traces the evolution of elasmobranch science within ICES, examining advances in data quality, assessment methodologies, and the shifting priorities that have transformed this taxon from a marginal concern to a central focus of marine conservation and fisheries management. Past and present Working Group Chairs provide perspectives on key developments, persistent challenges, and future directions for elasmobranch research and advice.

Understanding population structure from genetic analysis is crucial for species conservation and fisheries management, especially in vulnerable taxa like chondrichthyans where their life‐history can make them susceptible to anthropogenic activities. The starry smooth‐hound ( Mustelus asterias ) is a medium‐sized demersal shark which occurs in the Northeast Atlantic Ocean and the Mediterranean Sea, where dispersal patterns and spatial differences in life‐history traits suggest the presence of two or more biological stocks. This study examined the genetic diversity, haplotype distribution and genetic population structure of mitochondrial DNA from 124 individuals to investigate the existence of multiple biological stocks. A 6 kilobase pair (kbp) amplicon containing primarily coding regions was sequenced for all individuals and complemented by a 3.5 kbp amplicon of 78 specimens, containing a large noncoding section. The majority of genetic diversity was observed within sampling regions, rather than among potential biological stocks. The population structure of M. asterias was best explained by three or five genetic clusters, but these did not correlate with sample regions or potential biological stocks. Unexpectedly, individuals from the Mediterranean Sea were genetically similar or even identical to those from the Northeast Atlantic Ocean. Large gaps were present between genetic clusters, showing a unique pattern for elasmobranchs in the Northeast Atlantic Ocean. Male‐mediated gene flow, sex‐specific homing behaviour and spatial expansion following the last ice age may explain the observed population structure and previously documented spatial life‐history traits variations. Although no distinct biological stocks were confirmed, their philopatry makes M. asterias vulnerable to localized (anthropogenic) stressors.

Skates and rays (Batoidea) play a significant ecological role, contributing to ecosystem services through bioturbation and acting as vital intermediate components of the trophic chain in various aquatic environments. Despite their wide global distribution and ecological importance, batoids receive less attention than their shark relatives, resulting in substantial knowledge gaps that might impede a comprehensive understanding of their conservation status. This review addresses critical aspects of their capture, handling, tagging, and release to provide readers with crucial information needed to perform research on batoids. Protocols for analgesia, anaesthesia, and euthanasia are also discussed, taking into account the ethical and logistical considerations necessary for research involving this group of species. This information can give researchers and ethics committees the knowledge to conduct and approve studies involving batoids, thereby promoting more effective and ethical research practices.

Pelagic stingray (Pteroplatytrygon violacea) is the only species of stingray (Dasyatidae) that utilizes both pelagic and demersal habitats. It is the main bycatch species in pelagic longline fisheries targeting bluefin tuna (Thunnus thynnus) in the Gulf of Lions. In the Mediterranean Sea, their stock structure, behavioural ecology and movements are unknown. For the first time in the Mediterranean, 17 individuals (39–60 cm disc width) were tagged with pop-up satellite archival transmitting tags using a novel method of tag attachment to investigate horizontal and vertical movements. The tags were attached for between two and 60 days. Between the months of July and October, pelagic stingray occupied a temperature range of 12.5–26.6 °C, and a depth range extending from the surface to 480 m. Monthly trends in catch-per-unit-effort (CPUE) of pelagic stingray peaked in August and decreased by late autumn. Pelagic stingray may aggregate on the continental shelf during summer and move southwards in early autumn, and this movement pattern is considered in relation to the reproductive cycle and overwintering. At-vessel mortality was low, but there was varying evidence of post-release mortality, indicating the need for further work. Future work and options for bycatch mitigation are also discussed.

Pelagic stingray (Pteroplatytrygon violacea) is the only species of stingray (Dasyatidae) that utilizes both pelagic and demersal habitats. It is the main bycatch species in pelagic longline fisheries targeting bluefin tuna in the Gulf of Lions. In the Mediterranean Sea, their stock structure, behavioural ecology and movements are unknown. For the first time in the Mediterranean, 17 individuals (39 to 60 cm disc width) were tagged with pop-up satellite archival transmitting tags using a novel method of tag attachment, to investigate horizontal and vertical movements. The tags were attached for between two and 60 days. Between the months of July and October, pelagic stingray occupied a temperature range of 12.5 to 26.6°C, and a depth range extending from the surface to 480 m. Monthly trends in catch-per-unit-effort (CPUE) of pelagic stingray peaked in August and decreased by late autumn. Pelagic stingray may aggregate on the continental shelf during summer, and move southwards in early autumn, and this movement pattern is considered in relation to the reproductive cycle and overwintering. Future work and options for bycatch mitigation are discussed.

Skates (Rajidae) include species of conservation and commercial importance, but there is limited information regarding their ecologically important habitats, including spawning and nursery areas, in northern European seas. Data on the distribution, relative abundance and length composition of skates were collated from scientific trawl surveys, and based on length‐frequency information, length‐at‐hatching and length‐at‐maturity, skates were allocated to length‐based categories representing early‐juvenile stages (EJS) and mid‐juvenile stages (MJS). Citizen science data were used to inform on the occurrence of eggcases. The Great Eggcase Hunt (starting in 2003) citizen science recording project collects georeferenced data for elasmobranch eggcases, primarily from around the British Isles. This provided verified species‐specific data for a total of 227,407 specimens from 11 skate species. Purse Search Ireland (starting in 2005) provided a further 2491 records of 10 skate species from around Ireland. The most frequently observed skate eggcases were from the genus Raja and occurred around much of the British Isles. The EJS and MJS of such species were observed most frequently in inshore waters. Data for EJS were more limited for Raja microocellata and Raja undulata, indicating that the EJS of these species occur in shallower (Leucoraja occurred further offshore. Only the eggcases of Leucoraja naevus were recorded regularly, with the eggcase of Leucoraja fullonica described here. The data collated here provide an overview of skate spawning and nursery areas, thus informing fisheries management and marine spatial planning, including the identification and delineation of Important Shark and Ray Areas (ISRAs).

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements.

Angel sharks (Squatinaspp.) are distributed in warm temperate to tropical waters around the world. Many species occur in shelf seas and exhibit seasonal inshore–offshore migrations, moving inshore to give birth. Consequently, there can be high spatial overlap of angel shark populations with fisheries and other human activities. Their dorso‐ventrally flattened body shape, large size (most species attain >100 cm total length,L_T) and demersal nature means that they may be taken in a variety of demersal fishing gears from birth. Available data indicate that angel sharks typically have a biennial reproductive cycle, with litter sizes generally c. 20–30 cm. The biological characteristics of angel sharks render them susceptible to overexploitation, as exemplified by the decline ofSquatina squatinafrom many parts of its former range in the north‐east Atlantic and Mediterranean Sea. Currently, half of the 22 recognized extant species of angel shark are classed as Threatened on the International Union for Conservation of Nature (IUCN) Red List (with a further three classified as Data Deficient). Given the biological vulnerability of angel sharks, and that many species are data‐limited, the current paper provides a review of available biological information and fisheries data pertaining to this family.

Commercial landings of starry smooth-hound Mustelus asterias in northern European seas are increasing, whilst our knowledge of their ecology, behaviour and population structure remains limited. M. asterias is a widely distributed demersal shark, occupying the waters of the southern North Sea and Irish Sea in the north, to at least the southern Bay of Biscay in the south, and is seasonally abundant in UK waters. There are no species-specific management measures for the northeast Atlantic stock, and the complexity of its population structure is not yet fully understood. To address this issue, we deployed both mark-recapture and electronic tags on M. asterias to gain novel insights into its horizontal and vertical movements. Our data suggest that the habitat use of M. asterias changes on a seasonal basis, with associated changes in geographical distribution, depth utilisation and experienced temperature. We report the first direct evidence of philopatry for this species, and also provide initial evidence of sex-biased dispersal and potential metapopulation-like stock structuring either side of the UK continental shelf. Investigations of finer-scale vertical movements revealed clear diel variation in vertical activity. The illustrated patterns of seasonal space-use and behaviour will provide important information to support the stock assessment process and will help inform any future management options.

The stomach contents of 640 starry smooth‐hound Mustelus asterias from the north‐east Atlantic were examined. The diet was dominated by crustaceans (98.8% percentage of index of relative importance, %IRI), with the two main prey species being hermit crab Pagurus bernhardus (34% IRI) and flying crab Liocarcinus holsatus (15% IRI). Ontogenetic dietary preferences showed that smaller individuals [20–69 cm total length (L_T) n = 283] had a significantly lower diversity of prey than larger individuals (70–124 cm L_T, n = 348); however, 18 prey species were found exclusively in smaller individuals and eight prey taxa were found exclusively in larger individuals. Larger commercially important brachyurans such as edible crab Cancer pagurus and velvet swimming crab Necora puber were more prevalent in the diet of larger individuals. Specimens from the North Sea ecoregion had a lower diversity of prey types for a given sample size than fish from the Celtic Seas ecoregion. Whilst cumulative prey curves did not reach an asymptote, this was primarily due to the high taxonomic resolution utilized and 95% of the diet was described by just seven crustacean taxa. The trophic level (TL) was calculated as 4.34 when species‐level prey categories were used. This fine‐scale taxonomic resolution resulted in a TL estimate close to a whole level above that estimated using wider taxonomic groupings. This large bias has important methodological implications for TL studies based on categorized prey data, particularly those of predatory fish.