Summary
This study is based on seventeen years of fishery observer data collected aboard drift gillnet vessels fishing for swordfish and sharks in the California Current (United States). Since use of acoustic pingers began in 1996 (source level ∼135 dB RMS, re: 1 Pa @ 1 m, frequency 10–12 kHz, pulse duration = 300 ms, pulse interval = 4 s), there have been no beaked whale entanglements through 2006, in comparison to 33 entanglements from 1990-1998. 260 cetaceans representing 12 other species were observed entangled in the fishery from 1996-2006.