Marine mammal bycatch in the California/Oregon swordfish and thresher shark drift gillnet fishery in 2008

Details

• Personal Author:
  Carretta, James V. ; Enriquez, Lyle
• Corporate Authors:
  Southwest Fisheries Science Center (U.S.)
• NOAA Program & Office:
  NMFS (National Marine Fisheries Service) ; SWFSC (Southwest Fisheries Science Center)
• Description:
  Marine mammal bycatch is reported for the California/Oregon large mesh drift gillnet fishery, based on fishery observer data collected in 2008. Estimates of bycatch are generated using ratio estimation methods. Other fisheries observed in 2008 include a deep-set longline fishery (at 100% observer coverage), but data confidentiality regulations prevent the reporting of observer information from this fishery because only one vessel was active. Observations in coastal purse seine fisheries for squid, mackerel, anchovy, and sardine were also made in 2008 (63 observed sets) and no marine mammal injuries or deaths occurred. In the California/Oregon large mesh drift gillnet fishery for thresher sharks and swordfish, 149 sets were observed out of an estimated 1,103 sets fished by all vessels (13.5% observer coverage). Observed bycatch totals were eight short-beaked common dolphins (Delphinus delphis), five Pacific white-sided dolphins (Lagenorhynchus obliquidens), one northern right whale dolphin (Lissodelphis borealis), one Risso's dolphin (Grampus griseus), one long-beaked common dolphin (Delphinus capensis) and seven California sea lions (Zalophus californianus). All marine mammals were dead upon retrieval. Estimated bycatch is 59 (CV=0.43) short-beaked common dolphins; 37 (CV=0.70) Pacific white-sided dolphins; 7 (CV= 0.99) northern right whale dolphins; 7 (CV=0.99) Risso's dolphins; 7 (CV=1.08) long-beaked common dolphins and 51 (CV=0.52) California sea lions.
• Content Notes:
  James V. Carretta and Lyle Enriquez. ; "June 2009." ; System requirements: Adobe Acrobat Reader. ; Includes bibliographical references (page 5).
• Series:
  Administrative report LJ ; 09-03
• Document Type:
  Administrative Report
• Place as Subject:
  California ; Pacific Coast ; Oregon
• Rights Information:
  Public Domain
• Compliance:
  Library
• Download URL:
  https://repository.library.noaa.gov/view/noaa/4678/noaa_4678_DS1.pdf
• File Type:
  [PDF - 342.61 KB]
• Collection(s):
  National Marine Fisheries Service (NMFS)
• Main Document Checksum:
  urn:sha256:570d7c8e9af3af07d9e0f0e40a8879e909593bbd94a0021bc905345e1d742000