Estimates of cetacean and pinniped bycatch in Northeast and Mid-Atlantic bottom trawl fisheries, 2008-2013

• Main Author: Lyssikatos, Marjorie
• Format: Text
• Language: unknown
• Published: U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Northeast Fisheries Science Center 2015
• Subjects: Bycatches Fisheries > Atlantic Coast New England; Bycatches Fisheries > Atlantic Coast Middle Atlantic States; Trawls and trawling > Environmental aspects > Atlantic Coast New England; Trawls and trawling > Environmental aspects > Atlantic Coast Middle Atlantic States; Balaenoptera acutorostrata; Northwest Atlantic; Phoca vitulina; Phocoena phocoena
• Online Access: https://dx.doi.org/10.7289/v5348hb4; https://repository.library.noaa.gov/view/noaa/5041

This report provides bycatch mortality estimates for 10 species of small cetaceans and pinnipeds caught in Northeast (NEBT) and mid-Atlantic (MABT) bottom trawl fisheries during 2008-2013. Mean annual serious injuries and mortalities from the NEBT fishery were 1.40 (coefficient of variation [CV]=0.58) minke whales (Balaenoptera acutorostrata), 46.48 (CV=0.17) short-beaked common dolphins (Delphinus delphis), 0.43 (CV=0.79) Risso’s dolphins (Grampus griseus), 24.74 (CV=0.15) long-finned pilot whales (Globicephala melas), 3.10 (CV=0.50) harbor porpoise (Phocoena phocoena), 69.60 (CV=0.13) Atlantic white-sided dolphins (Lagenorhynchus acutus), 3.96 (CV=0.63) offshore common bottlenose dolphins (Tursiops truncatus), 30.76 (CV=0.14) gray seals (Halichoerus grypus), 1.40 (CV=0.69) harp seals (Phagophilus groenlandicus), and 2.64 (CV=0.38) harbor seals (Phoca vitulina concolor). Mean annual serious injury and mortality in the MABT fishery were 179.81 (CV=0.14) shortbeaked common dolphins, 38.28 (CV=0.28) Risso's dolphins, 15.71 (CV=0.42) offshore common bottlenose dolphins, 28.06 (CV=0.39) gray seals, and 11.40 (CV=0.40) harbor seals. Mean annual serious injury and mortality estimates for 8 species described in this report are below their respective potential biological removal (PBR) levels. The 2 exceptions are gray and harp seals that have unknown PBRs. There was evidence of acoustic deterrent devices being used on bottom trawl gear primarily in the MABT fishery, resulting in higher bycatch rates for offshore bottlenose dolphin and Risso's dolphins when pingers were used. Observer reports show no evidence of continued use of pingers on bottom trawl gear since 2012. However, uncertainty exists on the use of pingers and their effect on bottom trawl bycatch rates given nonsystematic data collection by fisheries observers on pinger usage in NEBT and MABT fisheries in the Northwest Atlantic region.