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Accession Number PB2013-106495
Title Marine Mammal and Seabird Bycatch in California Gillnet Fisheries in 2011.
Publication Date Nov 2012
Media Count 18p
Personal Author J. V. Carretta L. Enriquez
Abstract Bycatch of marine mammals and seabirds is reported for the California swordfish and thresher shark drift gillnet fishery and the California halibut and white seabass set gillnet fishery from fishery observer data collected in 2011. Bycatch estimates are generated using ratio estimation methods. There was no observed bycatch of sea turtles in California fisheries in 2011. Two additional fisheries (CA pelagic longline and CA small-mesh drift gillnet) were also observed in 2011 with no observed bycatch of marine mammals, sea turtles, or seabirds. Observations in the CA swordfish and thresher shark drift gillnet fishery included 85 sets during 19 fishing trips, from an estimated 435 sets fished by all vessels (19.5% observer coverage). Observed bycatch included two short-beaked common dolphins (Delphinus delphis), one longbeaked common dolphin (Delphinus capensis), one Risso's dolphin (Grampus griseus), one northern right whale dolphin (Lissodelphis borealis), and 18 California sea lions (Zalophus californianus). In addition, one minke whale (Balaenoptera acutorostrata) was reported released alive. Estimated bycatch is 10 (CV=0.69) short-beaked common dolphins, 5 (CV=1.02) long-beaked common dolphins, 5 (CV=1.02) Risso's dolphins, 5 (CV=1.05) northern right whale dolphins and 95 (CV=0.79) California sea lions. Observations in the CA halibut and white seabass set gillnet fishery included 171 sets during 47 fishing trips, from an estimated 2,123 sets fished by all vessels (8% observer coverage). Observed bycatch included six California sea lions, four Brandt's cormorants (Phalacrocorax penicillatus), and 16 unidentified cormorants (Phalacrocorax sp). Estimated bycatch is 74 (CV=0.39) California sea lions, 49 (CV=0.61) Brandt's cormorants and 198 (CV=1.03) unidentified cormorants. Observations in the CA yellowtail, barracuda, and white seabass drift gillnet fishery included seven sets during two fishing trips, from an estimated 209 sets fished (3.3% observer coverage). No bycatch of marine mammals, sea turtles, or seabirds were observed. Other fisheries observed in 2011 include the CA pelagic longline fishery that operates outside of the U.S. Exclusive Economic Zone. Sixty-eight sets were observed (at 100% observer coverage), with no bycatch of marine mammals, sea turtles, or seabirds.
Keywords Bycatch
California
Data collection
Estimates
Fisheries
Marine mammals
Sea lions
Seabirds
Ships
Turtles

 
Source Agency National Oceanic and Atmospheric Administration
National Marine Fisheries Service
NTIS Subject Category 47D - Biological Oceanography
57H - Ecology
48B - Natural Resource Management
98F - Fisheries & Aquaculture
Corporate Author National Marine Fisheries Service, La Jolla, CA. Southwest Fisheries Science Center.
Document Type Technical report
Title Note N/A
NTIS Issue Number 1314
Contract Number N/A

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