• gray whale;
  • Eschrichtius robustus;
  • prey;
  • feeding patterns;
  • habitat;
  • Vancouver Island;
  • oil


Habitat utilization and prey species of Vancouver Island gray whales were investigated by (1) summarizing 26 yr of distribution and feeding data and (2) conducting intensive observations in Clayoquot Sound, Vancouver Island, from 1989 to 1996. Whale distribution and movements were monitored from March to November through systematic boat surveys and whale-watch sighting programs. Prey species were collected by suction hose and plankton net or determined through analysis of fecal samples. Gray whales utilized virtually all of the southern west coast of Vancouver Island over the 26-yr observation period. Distribution, prey species, and feeding behavior showed marked variability during any one season and between years. Some feeding areas were used on an annual basis, others with >10-yr intervals between use. Feeding occurred in shallow sand or mud bays, eel grass beds, kelp beds, in the open water column, and at the surface. Young whales appeared to utilize habitat and prey species differently than adults. Main prey species included herring eggs/larvae (Clupea harengus pallasi), crab larvae (Cancer magister megalops, Pachycbeles spp. zoea), mysids (Holmesimysis sculpta, Neomysis rayii, Acanthomysis spp.), amphipods (Ampelisca spp., Atylus borealis), and ghost shrimp (Callianassa californiensis). The definition and relative importance of specific feeding grounds and the study of human impacts on this population are complicated by its broad and variable use of habitat and prey species.