Submitted by the Orca Behavior Institute.

The endangered Southern resident killer whales, known for frequenting the inland waters of Washington state and British Columbia during the spring and summer months, have been absent from the Salish Sea for an unprecedented eight weeks spanning all of June and most of May.

Traditionally, May through September has been known as the peak season for seeing these salmon-eating whales. The Southern residents used to be present on a near-daily basis during these months, leading both the United States and Canada to designate the inland waters as their critical habitat. But in recent years, things have radically changed. The reason? It all comes back to prey.

“The lack of Southern residents in the Salish Sea for the entirety of June reflects a fundamental shift in the behavior of this population,” said Michael Weiss, a scientist with the Center for Whale Research. “Dramatic changes in the distribution of Chinook salmon, particularly due to the ongoing decline of Fraser River stocks, have increasingly forced these whales to abandon an area that was once their core habitat.”

In 2007, Orca Network proclaimed the first annual Orca Month in June. “Historically by the end of June, the Center for Whale Research would have had a chance to see and survey all three pods of the Southern Resident orcas, and know of any births or deaths,” explained Susan Berta of Orca Network. “Over the two decades we have collected sightings through our Whale Sighting Network, the date for the final survey has been later and later in the summer. …The total absence of Southern Resident orcas in the Salish Sea during June is a disturbing sign of the drastic changes in prey availability.”

The assumption is that J, K, and L pods are all on the outer coast somewhere, hopefully finding a more reliable source of salmon than the Fraser River. “Their finding food is, of course, more important than our being able to see them,” said Monika Wieland Shields, president of the Orca Behavior Institute. “But it’s important to acknowledge both the loss we humans feel in their absence, and what their not being here is telling us about the health of the Salish Sea.”

Whitney Neugebauer, director of Whale Scout, agrees. “The absence of Southern residents tells us that the ecosystem is out of balance. We should be listening and responding appropriately. If the whales can’t make a living in our inland waters, we, too, are in trouble.”

Meanwhile, mammal-eating Bigg’s killer whales are thriving, and continue to be seen in the Salish Sea in record numbers. “We’ve been seeing Bigg’s orcas most days this entire season and so many of their families have young calves,” said Jeff Friedman, president of the Pacific Whale Watch Association. “The Bigg’s orcas are showing us that these animals will thrive with abundant food. Unfortunately, this isn’t the case for their fish-eating cousins, the Southern residents. Our hope is that policymakers in the U.S. and Canada are taking note of the opposite directions these populations are taking.”

“Unless immediate, dramatic action is taken to recover these vital salmon populations, this won’t be the last June without Southern residents in our waters,” said Weiss.

As for when the Southern residents will return, at this point, it is anyone’s guess.