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

ICES summarizes estimates of the annual total numbers of specimens taken as bycatch and multiannual bycatch rates of endangered, threatened, and protected (ETP) species of marine mammals, seabirds, fish, and marine turtles, based on reported bycatch and monitoring data received through ICES data call.

The bycatch evaluation and assessment matrix (BEAM) process was applied for the first time to the data from ICES data calls to assess representativeness of the monitoring data. Multiannual bycatch rates and total annual bycatch estimates were subsequently calculated for 151 out of 584 combinations of ecoregion, métiers, and species for which bycatch data was available.

Annual bycatch estimates of priority species identified by DGMARE are provided for combinations of ecoregion, métier and species which passed the BEAM process. This covers one marine mammal species (short beaked common dolphin, Delphinus delphis) in two ecoregions, three species of marine turtles (leatherback, Dermochelys coriacea, loggerhead, Caretta caretta, and green turtle Chelonia mydas) in seven ecoregions and four species of fish (European sturgeon (Acipenser oxyrinchus), common skate (Dipturus intermedius), spiny butterfly ray (Gymnura altavela) and beluga sturgeon (Huso huso)) in seven ecoregions.

ICES highlights that the bycatch risk of harbour porpoise (Phocoena Phocoena) in the Black Sea turbot gillnet fisheries is higher in summer compared to spring, drifting longlines pose the major risk for bycatch of marine turtles, and bycatch of the high-priority skate and ray species occurs more frequently in bottom otter trawl, trammelnets and set gillnet. Bycatch of monk seal in set longline fisheries in the Aegean-Levantine Sea ecoregion remains a concern.

In addition to priority species, ICES notes that relatively high multiannual (2018–2022) bycatch rates (defined as individuals taken as bycatch per monitored day-at-sea) were estimated for several species. Examples of these are harbour seal (Phoca vitulina) in fykenets in the Greater North Sea ecoregion, northern fulmar (Fulmarus glacialis) in set longlines in the Icelandic Waters ecoregion, and blackbelly rosefish (Helicolenus dactylopterus) and Norway redfish (Sebastes viviparus) in otter trawls in the Oceanic Northeastern Atlantic ecoregion.

ICES reiterates that the monitoring data for many areas and métiers are insufficient, as indicated by the low proportion of ecoregion/métier/species combinations retained after the BEAM process to provide reliable bycatch estimates for most ETP species.

ICES highlights that the lack of population estimates and validated thresholds for most ETP species hampers evaluation of the population level impacts of bycatch.