What we know and don’t know about killer whales

This week’s report about Puget Sound’s endangered killer whales contained little new information, but the intent was not to surprise people with important new findings. The report (PDF 14.3 mb), published by the Northwest Fisheries Science Center, was a nice summary of 10 years of research and ongoing efforts to unlock the secrets of the mysterious Southern Residents.

NOAA also released the video, at right, which sums up the report with great visuals. Make sure you go full-screen.

On Wednesday, I participated in a telephone conference call to link reporters with killer whale experts in our region. On the line were Lynne Barre, Mike Ford and Brad Hanson, all with NOAA Fisheries out of Seattle. I’ve been wrapped up with other reporting assignments, so the Kitsap Sun’s editors chose to run a solid story by Associated Press reporter Phuong Le. See Kitsap Sun, June 25.

Let me make a few quick observations:

Lynne Barre said one of the greatest mysteries, to her, is why killer whales suddenly go missing. It’s a vexing problem, and I always get a little nervous when the whales return in the spring. One year, six of the Southern Residents failed to show up. It was a real blow to the close-knit orca community and to the struggling population, and I’ve never forgotten the dismay of everyone who cared about these animals.

Healthy killer whales seem to go missing as often as elderly or sick ones. Only a few bodies ever wash up on the beach. Even when one is found, the cause of death often remains uncertain, as in the case of L-112, found to have died of “blunt-force trauma” from some unknown object.

Much more needs to be learned about disease in the animals, Lynne said. Future research could involve more tissue biopsies and breath samples in an effort to identify early signs of disease.

For Brad Hanson, another mystery is the whales’ seemingly unpredictable behavior and their “fundamental relationship with prey.” We all assume that their primary goal in life is to find fish to eat, but how good are they at this essential task? Pretty good, I would guess. Often before we learn that chinook are abundant off the Washington Coast, we find out that the killer whales are already there.

Maybe the reason the whales have been spending so much time away from Puget Sound the last couple years lies in the lower returns of Fraser River chinook, which pass through the San Juan Islands in the summer. Scale and fecal samples have shown that Fraser River chinook are the most consistent prey of the resident orcas.

In previous conversations, Brad has told me that he would love to communicate with the whales, to find out who is in charge and why a group of animals may suddenly turn around and go in the opposite direction. Howard Garrett of Orca Network recalls a time when all three Southern Resident pods were in the Strait of Juan de Fuca heading into Puget Sound. Suddenly K and L pod turned back, while J pod continued on. Howie says it was as if they knew there were not enough fish for the entire population, so J pod went on alone, saying, “See ya later.”

Mike Ford wants to know why the population has not increased more than it has. Could it be some limitation in the ecosystem, such as the fact that other marine mammals — such as seals and sea lions — have been increasing and taking a sizable bite out of the available salmon population? We know that Northern Residents, who also eat fish, don’t overlap territories much with the Southern Residents. Living up north, the Northern Residents have better access to some salmon stocks — including those that originate in Puget Sound. If the Northern Residents get to them first, the fish are not available for the Southern Residents — or so goes one hypotheses. The Northern Resident population has tripled in size, while the Southern Residents have stayed about the same.

Oddly enough, this potential competition for chinook salmon reminds me of exactly what is taking place with regard to commercial fishing enterprises. Washington fishermen complain that the Canadians are taking salmon that should get back to Washington. Canadian fishermen complain that Alaskans are taking salmon bound for Canada. Only Alaskan fishermen — and those who go to Alaska to fish — can catch a portion of the salmon going into Alaskan rivers as well as some destined to travel south.

One of the new things that did come up in Wednesday’s conference call was a renewed effort for U.S. killer whale biologists and managers to work with their counterparts in Canada. “We will be partnering with them on issues of salmon fisheries and how that may affect the whales,” Lynn said, adding that other cross-border efforts could involve vessel regulations and targeted research efforts.

During Wednesday’s conference call, nobody talked about the potential effects of military activities and the possible injury from Navy sonar until a reporter brought up the issue. The question was referred to NOAA Fisheries headquarters in Silver Spring, Md., where officials review the Navy’s operations and issue incidental take permits. That was the end of that discussion.

I know the Navy is conducting research in an effort to reduce harm to killer whales and other marine mammals. I get the sense, however, that more could be done immediately if connections were made between knowledgeable killer whale researchers in our region and those making decisions on the opposite side of the country.

SouthernResidentKillerWhalePhoto

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