Environmental characteristics of north Atlantic right and fin whale habitat in the lower Bay of Fundy, Canada

Characteristics of right whale (Eubalaena glacialis) and fin whale (Balaenoptera physalus) habitat in the lower Bay of Fundy were identified by quantifying physical and biological habitat variables and comparing them to the distribution of whales during the summer and autumn of 1989. Right whales were generally distributed over the Grand Manan Basin, where the bottom topography is relatively flat and the water column was stratified. Calanus finmarchicus, the principal prey species of right whales, was the predominant copepod taken in zooplankton hauls, and the depth-averaged density (mean 1139/m(3)) was significantly greater where right whales were present. Fin whales were distributed mainly in shallower areas with high topographic variation that were likely well mixed or contained frontal interfaces between mixed and stratified waters. Herring (Clupea harengus) and euphausiids, both known prey of fin whales, were relatively abundant on echosounder traces in areas where fin whales were present. The habitats of both whale species were primarily characterized by high densities of principal prey species and the physical conditions that facilitate the accumulation of these prey.