It's a rare sight in Vancouver's False Creek, but a pod of orcas was spotted swimming the city's most inner waterway on Wednesday.

One whale-watched said it appeared to be a mother orca with a large dorsal fin and three to four young orcas.

Researchers say their absence is a stark reminder that the orcas are slowly starving to death because there is not enough Chinook salmon to sustain them.

Southern resident killer whales made their first appearance in the Salish Sea on Canada Day after more than two months with only a brief sighting off the west coast of Vancouver Island.