Marine mammal and sea turtle bycatch in the California/Oregon swordfish and thresher shark drift gillnet fishery in 2009.

Marine mammal and sea turtle bycatch is reported for the California/Oregon large-mesh drift gillnet fishery, based on fishery observer data collected in 2009. Estimates of bycatch are generated using ratio estimation methods. One other fishery, the deep-set longline fishery, was observed at 100% observer coverage during 2009, but data confidentiality regulations prevent the reporting of observer information from this fishery because only one vessel was active. In the California/Oregon large-mesh drift gillnet fishery for thresher sharks and swordfish, 101 sets during 17 fishing trips were observed out of an estimated 761 sets fished by all vessels (13% observer coverage). Observed bycatch included one short-beaked common dolphin (Delphinus delphis), two Pacific white-sided dolphins (Lagenorhynchus obliquidens), and five California sea lions (Zalophus californianus). All marine mammals were dead upon retrieval. Estimated bycatch is 7 (CV=1.11) short-beaked common dolphins, 15 (CV=1.02) Pacific white-sided dolphins, and 37 (CV=0.83) California sea lions. In addition to the observed marine mammal bycatch, there was one leatherback turtle (Dermochelys coriacea) released alive in this fishery in 2009.