Authors: Morkunas, Julius; Morkūnė, Rasa;Rouxel, Yann ;

Bycatch – the incidental capture of non-target species in fisheries – has been identified as one of the major threats affecting seabird populations worldwide. In the Baltic Sea, a globally important area for wintering seabirds, bycatch in gillnets represents an important cause of human-induced mortality for seabird species. Countries are required by European law to report official bycatch data, mostly done in a very irresponsible way. This study presents data collection improvements on the total seabird bycatch in the small-scale coastal fishery for the entire Lithuania, in the Baltic Sea, during the winter period from 2015–2020. An average of 19.3% of the total fishing effort were observed each winter season, resulting in observations of 909 bycaught birds from 15 species vs 6 bird in official data. Two species comprised two-thirds of the total bycatch, Long-tailed Duck, Clangula hyemalis (42.1%), and Velvet Scoter, Melanitta fusca (35.4%). We estimate that between 1,500 and 3,000 seabirds were bycaught annually in the Lithuanian small-scale coastal fishery during the study period. Our study highlights deficiencies and inadequate the country’s current bycatch reporting. Alongside improved data collection, effective ways to mitigate seabird bycatch should be developed, starting from alternative fishing gears or mitigation.