Large Whale Entanglement Mitigation

Photo: Jerry Conway. Organization: Campobello Whale Rescue Team.

The North Atlantic right whale (Eubalaena glacialis), a species restricted to the coastal northwest Atlantic, numbers fewer than 409 individuals and has been declining since 2010 (Pace et al. 2017; Pettis et al. 2019, in prep.). Entanglement in fishing gear, especially in fixed gear like pots and gillnets, is the leading cause of human-induced mortality and serious injury, occurring at a rate that is not sustainable for maintaining a viable population. Entanglement mortalities and serious injuries consistently exceed the regulatory limits of the Potential Biological Removal rate set under the Marine Mammal Protection Act (presently less than one whale (0.9) per year is allowed to be taken by human activities; see NOAA’s 2018 Stock Assessment Report for North Atlantic right whales). In 2017, 17 North Atlantic right whales were found dead in the U.S. and Canada, compared with an annual average of 3.8 per year. As a result of this elevated mortality rate, NOAA Fisheries declared an Unusual Mortality Event for this species.  In 2018, four right whales were found dead, three as a result of entanglement. Zero calves were born that year. There were also three live entangled right whales with attached gear and one with severe entanglement injuries documented from July – Aug 2018. In 2019, there were ten dead right whales observed, nine in the months of June and July, and one in September. Four actively entangled whales were also observed, one that was seen entangled and later showed up as the tenth dead whale, and one that has since been disentangled. On June 25, 2020, the first dead right whale of the season was found. Cause of death is yet unknown. In short, to avert the near-term possibility of extinction of this species, we urgently need to eliminate the threat to these whales from entanglements in fishing ropes.

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Project PI(s): 

Scott Kraus, Tim Werner, Amy Knowlton
Research Program: 
Fishery Animal Interactions