THE IMPACT OF ENTANGLEMENTS ON 2 SUBSTOCKS OF THE WESTERN NORTH-ATLANTIC HUMPBACK WHALE, MEGAPTERA-NOVAEANGLIAE

Increased use of fishing gear in the marine environment can be detrime ntal to animals such as cetaceans, particularly through entanglement. Examination of the impact of such mortality on two substocks of the we stern North Atlantic humpback whale, Megaptera novaeangliae, indicates that when entanglement losses are added to natural mortality estimate s and subtracted from birth rate estimates, annual mortality may be as high as 5.4% in the Newfoundland and Labrador population and 4.8% in the Gulf of Maine population. More effective entanglement reporting an d assisting systems are needed in the Gulf of Maine and increased effo rts are needed to decrease entanglements, entanglement mortalities, an d damages to fishing gear. We conclude that monitoring of the size of humpback populations needs to continue, given their particular vulnera bility to coastal fishing and the potential impacts of entanglement mo rtality.