Summary
This study investigated and summarized trends in US marine mammal bycatch from 1990-2017. Total annual bycatch was estimated to be 4296 ± 1789 individuals, and the vast majority occurred in gillnets; 52% of marine mammal bycatch consisted of pinnipeds, while the other 48% was cetaceans. Total marine mammal bycatch in US fisheries declined from 1990 to 2002 following the passage of the MMPA in 1972, but there was no change in total bycatch from 2002 to 2017, suggesting that US bycatch mitigation measures have had some success. While bycatch levels declined through 2017 in the Atlantic-Gulf of Mexico-Carribbean region, reductions either halted or increased in the Pacific in Atlantic regions by 2006.