Bycatch of protected, endangered, and/or threatened species of marine mammals, seabirds and marine turtles, and selected fish species of bycatch relevance

ICES summarizes new bycatch information on marine mammals, seabirds, marine turtles, and fish in 2021, based on reported bycatch data received through the ICES data call.

ICES reiterates that current bycatch monitoring activities and sampling design in most cases do not yet allow for robust and unbiased estimations of numbers of sensitive species caught incidentally in fishing activities.

In the absence of estimations of absolute numbers, multiannual average bycatch rates are used to highlight species, métiers, and ecoregions where bycatch may be of particular concern. This information can be used to prioritize species or fishing métiers for monitoring and management measures. In 2017–2021, the highest bycatch rates for mammals were observed for harbour seals and harbour porpoises in set gillnets in the Icelandic Waters ecoregion, for grey seals in set gillnets in the Celtic Seas ecoregion, and for common dolphin in pair trawls in the Bay of Biscay and Iberian Coast ecoregion. For seabirds, the highest bycatch rates were observed for common guillemot and northern fulmar in set gillnets and longlines in the Icelandic Waters ecoregion and northern fulmar in longlines in the Greater North Sea ecoregion. From the three turtle species reported, the highest bycatch rates were found for the loggerhead sea turtles caught by drifting longline fisheries in the Azores ecoregion and in the Adriatic Sea.

ICES advises on other species and areas of bycatch concern which are currently not well represented in the bycatch monitoring data due to their rarity, including species with evidence of low or declining abundance and/or high susceptibility to bycatch. This includes the Baltic Proper subpopulation of harbour porpoise in the Baltic Sea ecoregion, the leatherback turtle subpopulation in the Oceanic Northeast Atlantic, Azores, and Bay of Biscay and Iberian Coast ecoregions, and the Balearic shearwater in the Western Mediterranean Sea and the Bay of Biscay and Iberian Coast ecoregion. It also includes several fish species, namely the European sturgeon in the Bay of Biscay and Iberian Coast and Greater North Sea ecoregions; Atlantic sturgeon in the Baltic Sea ecoregion; common blue skate/flapper skate in the Barents Sea, Norwegian Sea, Greater North Sea, Icelandic Waters, and Celtic Seas ecoregions; angel shark in the Celtic Seas ecoregion; basking shark in the Greater North Sea, Celtic Seas, and Bay of Biscay and Iberian Coast ecoregions; and great white shark in the Bay of Biscay and Iberian Coast ecoregions and in the Western and Central Mediterranean Sea, Ionian Sea, Adriatic Sea, and Aegean-Levantine Sea.