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• Use of fisheries-dependent data to undertake skate distribution models. • Broader scale skate spatio-temporal distributions than previously modelled. • Varying spatio-temporal distributions highlight differing skate vulnerability. • Use of skate life history distribution models for specific protection measures. • Use of fisheries dependent data to avoid bycatch. Elasmobranchs are k-strategy species with low reproduction rate and slow growth lending to increased anthropogenic vulnerability. Specific management measures to improve the conservation of elasmobranchs can be problematic due to insufficient information on their biology and ecology. Here, three sympatric skates occupying north-eastern Atlantic waters, which have differing conservation status were studied within ICES divisions 4.c, 7.d–e, 7.f–h and 8a–b and d. Fisheries-dependent data on skate bycatch and a series of environmental variables were used to model spatio-temporal differences in habitat use between the three species. Raja undulata , the undulate ray (IUCN red listed as 'Endangered') was observed to have a coastal distribution within the English Channel and the Bay of Biscay (ICES division 7.d–e and 8.a–b). Raja clavata, the thornback ray ('Near threatened'), had a broader distribution with higher presence in the eastern English Channel and the southern North Sea (ICES division 7.e and 4.c). Raja montagui , the spotted ray's probability of presence ('Least concerned') was higher off the coast of southern Ireland (ICES division 7.g). Seasonal and life-history trait differences were also observed. From the fisheries-dependent data, wider skate distributions than previously studied were modelled. Although the species do co-occur, spatio-temporal differences between these species were observed. This study contributes to a greater understanding of skate habitat during their different life history stages, and indicates reasons for R. undulata's increased vulnerability than R. clavata and R. montagui. Information from the distribution models could be used for specific spatio-temporal management measures. Better understanding of the distribution of species can also help reduce bycatch of protected species such as R. undulata. [ABSTRACT FROM AUTHOR]

• Fisheries-dependent data can fill gaps in knowledge of data-poor elasmobranch species. • L. fullonica is distributed within an area of high concentration where size segregation is present. • Its localized distribution is within an area subject to heavy fishing pressure. • L. fullonica is most susceptible to bycatch by bottom trawl fishing gear types. • Most of the L. fullonica individuals caught are immature. Little is still known about the biology and ecology of many elasmobranchs which often inhibits species specific management measures from being implemented. The primary aim of this study was to improve the knowledge on the distribution and habitat use of the threatened and data deficient shagreen ray, Leucoraja fullonica , using fisheries dependent data. To model its distribution, we used Bayesian hierarchical modelling, taking into consideration imperfect capture from the non-random nature of fishing gear type and spatial autocorrelation. Our second objective was to identify the potential functional role of the high occurrence area by analysing spatial length segregation using a generalised additive mixed model. From five environmental variables, depth, distance to coast, and seabed sediment type were used to model its habitat. L. fullonica was found to mainly inhabit an area of high concentration between the southern Celtic Seas and the northern Bay of Biscay. Within this area, smaller individuals were found in the deeper south-western part and larger individuals in shallower waters, closer to the coast, suggesting ontogenetic shift or spawning migration. L. fullonica were mainly caught by bottom trawl fishing gears. The isolated habitat occupancy of this species may increase its vulnerability, particularly since high fishing pressure has been observed in this area. These results highlight the importance of fisheries-dependent data for data-poor species and provide valuable new information on its ecology when considering management or conservation measures at a species level. [ABSTRACT FROM AUTHOR]