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Keywords:

  • entanglement;
  • entanglement risk;
  • mortality;
  • fisheries;
  • bycatch;
  • gear type;
  • North Atlantic right whale;
  • Eubalaena glacialis;
  • humpback whale;
  • Megaptera novaeangliae

Abstract

Interactions between marine mammals and fishing gear are an issue of global concern. Entanglements in the western North Atlantic are a major source of injury and mortality for endangered large whales. In this study, entanglements of 31 right whales (Eubalaena glacialis) and 30 humpback whales (Megaptera novaeangliae) were analyzed to determine the types and parts of gear involved. When gear was identified, 89% (n= 32) of the entanglements were attributed to pot and gill net gear; however, a wide range of specific gear types were implicated. Despite gear recovery, gear type was not identified in 20% (n= 9) of the cases. Although pot gear was recovered from both species equally, gill net gear was less frequently retrieved from right whales (n= 2) than humpback whales (n= 11). When gear part was identified, 81% (n= 21) involved entanglements in buoy line and/or groundline. For right whales, the most common point of gear attachment was the mouth (77.4%); for humpback whales, the tail (53%) and the mouth (43%) were common attachment sites. Four right and three humpback whales in this sample were known to have died subsequent to entanglement. However, when identified, the gear types and parts involved in lethal cases were not substantially different from entanglements with non-lethal outcomes. Large whales can become entangled in a wide variety of fishing gear types and parts, and additional insight will depend on continued efforts to document entanglements and recover associated gear.