Vital Signs | Orcas

PUGET SOUND VITAL SIGNS

Measures of ecosystem health and progress toward Puget Sound recovery goals

Orcas

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Killer whales, also called orcas, are among Puget Sound’s most distinctive and charismatic inhabitants. They occupy an important niche at the top of the food web and support a multi-million dollar whale-watching industry in Puget Sound. Southern Resident killer whales are a unique population of orcas that ranges in the Salish Sea and the West Coast. While the “transient” or Bigg’s killer whale populations in Puget Sound prey on marine mammals, Southern Resident killer whales primarily eat fish, and depend heavily on Chinook salmon for food.

VITAL SIGN INDICATOR	PROGRESS	STATUS

VITAL SIGN INDICATOR	PROGRESS	STATUS

Key Vital Sign Messages

Point Robinson, Maury/Vashon. By Marla Smith.

Year-round, Southern Resident killer whales depend heavily on Chinook salmon for food, thus linking orca recovery with that of Chinook salmon. Chinook salmon are a threatened species, whose numbers are designated in the Puget Sound Vital Signs as dangerously low and categorized as “not improving”.
Southern Resident killer whales spend a considerable portion of the year outside the Salish Sea, where they eat Chinook salmon from Puget Sound and other regions of Washington—including the Columbia Basin—and from other areas, like the Fraser and Klamath rivers. Therefore, improving prey availability outside Puget Sound is also fundamental to the resident orca recovery.
When Southern Resident killer whales can’t find enough to eat, they must burn their own fat—releasing harmful pollutants picked up from the Salish Sea and elsewhere into their tissues. Science suggests that poorer body condition increases the orcas’ vulnerability to disease and hinders reproduction.
In the Salish Sea, underwater noise and disturbance from commercial and recreational vessels force Southern Resident killer whales to forage longer for dwindling and smaller prey, compared to decades past. Recent studies show that reducing noise and improving access to prey are crucial for orca recovery.