The most common pod of southern resident killer whales who migrate to the Salish Sea during the summer have not been seen for than 100 days, marking a highly unusual absence from their historic summer hunting ground, according to researchers.

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.

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

Multiple groups of transient killer whales were spotted in the waters off Vashon Island Friday, according to the Vashon Hydrophone Project’s Ann Stateler (“Orca Annie”).