By Lynda V. Mapes

27 October 2017

(The Seattle Times) – Orca whales are on a path to extinction within a century unless they get a big increase of chinook salmon to eat, and significantly quieter seas in which to find their food, a new study has found.The research, published in the journal Scientific Reports, evaluated the relative importance of known threats to the survival of southern-resident killer whales, the salmon-eating whales that frequent Puget Sound.An international team of scientists reviewed 40 years of data and the threats of lack of food, pollutants, and excessive noise under different future scenarios.A clear finding emerged: lack of food, specifically chinook salmon, was the orcas’ biggest threat to long-term survival, so much so that a 30 percent increase in chinook above average levels is needed to recover the orca population. That increase could be cut to 15 percent if vessel noise also is reduced by half.Otherwise, the populations will continue to decline and there is a 25 percent chance the whales will be lost within 100 years, the scientists found. […]“The very first thing we should be doing is holding the line, and not increasing threats and harms that are already there, clearly we don’t want to be adding to the problem,” said Paul Paquet of the Raincoast Conservation Foundation in Sydney, B.C., a lead author on the paper.“There is an urgency here that is not well-appreciated; they are certainly in jeopardy,” he said of the orcas. “There is no doubt about that.”Bob Lacy, a conservation biologist with the Chicago Zoological Society, and another lead author on the paper, said the southern residents are “just holding on; the population is too fragile to withstand any increased threats.“It is not a cheerful story, but it is a wake-up call.”Lynne Barre, Seattle branch chief of the Protected Resources Division at NOAA Fisheries West Coast Region, said the agency is well aware of the orcas’ predicament, as their population — at the lowest numbers since the 1980s — continues to drop. They are listed as endangered under the Endangered Species Act.“We are moving in the wrong direction,” Barre said. The agency is looking for partners at every level — local, state, federal and across the border in Canada, to ease threats to orca survival she said. [more]