Two distinct species of orcas feed and socialize in the waters of Puget Sound: fish-eating endangered southern resident killer whales and transient, or Bigg’s, killer whales, which feed on marine mammals and are more common. They seldom mix.

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.

Swarms of anchovy can be seen swimming through the South Sound.

Southern resident orcas are on the brink of extinction, while killer whales to the north are growing in numbers. The contrast exposes what’s killing Puget Sound’s orcas.

The population of endangered killer whales has hit a 30-year-low, numbering only 75 this year.

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”).