Mortality determinations for Baleen whale stocks along the Gulf of Mexico, United States east coast, and Atlantic Canadian provinces, 2008-2012
The Northeast Fisheries Science Center (NEFSC) developed criteria to evaluate reports of human-caused mortality to baleen whales. The criteria minimize the likelihood of incorrectly assigning whale mortalities t o human causes and provide a minimum count of human-caused events. This report describes...
Main Authors: | , , , , , |
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Format: | Text |
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U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Northeast Fisheries Science Center
2014
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Online Access: | https://dx.doi.org/10.7289/v5jw8bvd https://repository.library.noaa.gov/view/noaa/4801 |
Summary: | The Northeast Fisheries Science Center (NEFSC) developed criteria to evaluate reports of human-caused mortality to baleen whales. The criteria minimize the likelihood of incorrectly assigning whale mortalities t o human causes and provide a minimum count of human-caused events. This report describes determinations made for reports received from 2008 - 2012 involving North Atlantic right (Eubalaena glacialis), humpback (Megaptera novaeangliae), fin (Balaenoptera physalus), sei (B. borealis), blue (B. musculus), minke (B. acutorostrata), and Bryde's (B. edeni) whales observed in United States waters in the Gulf of Mexico, along the US eastern seaboard and in the Atlantic Canadian provinces. We confirmed a total of 3 00 mortalities: 60 (20%) caused by human interaction, 14 (5%) because of natural causes, and 236 (75%) which lacked sufficient evidence to determine cause of death. Of the human-caused mortalities, 32 were due to entanglement and 28 were vessel strike. These mortality numbers are minimum counts because of a low probability of detecting events and inadequate documentation to determine cause of death for the majority of events that are detected. Despite the minimum values, the mean annual confirmed human-caused mortality rate exceeds the Potential Biological Removal (PBR) value for 4 of the 7 stocks examined, including North Atlantic right, humpback, sei, and Bryde's whales. The true level of anthropogenic mortality to these stocks is greater than these minimum values, but the amount greater is unknown. |
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