Results on main elasmobranch species from 2001 to 2021 Porcupine Bank (NE Atlantic) bottom trawl surveys

Abstract

This working document presents the results of the most significant elasmobranch species caught on the Porcupine Spanish Groundfish Survey (SP-PORC-Q3) in 2021. Biomass and abundance index, distribution and length frequency information is presented for Galeus melastomus (blackmouth catshark), Deania calcea (birdbeak dogfish), Deania profundorum (arrowhead dogfish), Scymnodon ringens (knifetooth dogfish), Scyliorhinus canicula (lesser spotted dogfish), Etmopterus spinax (velvet belly lantern shark), Dalatias licha (kitefin shark), Hexanchus griseus (bluntnose sixgill shark), Dipturus nidarosiensis (Norwegian skate), Dipturus batis (common skate), Dipturus intermedius (common skate), Leucoraja circularis (sandy ray) and Leucoraja naevus (cuckoo ray), Squalus acanthias (picked dogfish), Raja clavata (thornback ray) and Raja montagui (spotted ray). In 2021 the biomass of G. melastomus, D. calcea, S. ringens, D. licha, S. acanthias, L. naevus, L. circularis and D. batis increased, whereas it decreased for D. nidarosiensis, H. griseus, S. canicula and E. spinax. Signs of recruitment were found for G. melastomus, D. calcea, S. ringens, D. licha, D. nidarosiensis and D. batis. Only a few specimens of R. clavata, R. montagui, Centroscymnus coelolepis, Oxynotus paradoxus, Centroscymnus crepidater, Apristurus laurussonii, Galeus murinus and Centrophorus squamosus were caught. The species Centroscyllium fabricii and Neoraja caerulea were captured for the first time in the survey. The species D. profundorum and D. intermedius, with regular presence in the historical series, were not found in 2021 survey.