Shark predation on North Atlantic right whales (Eubalaena glacialis) in the southeastern United States calving ground

摘要

Aggregations of North Atlantic right whales (Eubalaena glacialis) can be found seasonally in one of five known habitats in the western North Atlantic: Bay of Fundy, Roseway Basin, Cape Cod Bay, Great South Channel, and the southeastern United States.A portion of the population including pregnant females, migrates to the southeast calving ground during the winter months.Leading contributions to mortality in right whales are entanglement in fishing gear and vessel collision (Knowlton and Kraus 2001, Moore etal. 2004). Determining the cause of death is more challenging for calves than for adults, and the majority of neonate necropsies are inconclusive (Moore et al. 2004). Undetected calf mortalities are likely far greater than documented cases, further under-representing mortality sources in this demographic (Browning et al. 2010). Predation pressure had not previously been considered a threat.