Mapping fish die-offs in warming waters

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This article first appeared in High Country News.

This year’s brutal heat and drought have meant grim news for the West: cataclysmic wildfires in Washington, contaminated drinking water in California, and the disappearance of Lake Mead, to name but a few Mad Max-like symptoms.

No one, however, has it worse than fish. Fish, as you are perhaps aware, need water, which is exactly what the West doesn’t have. On the Olympic Peninsula, the Washington Department of Ecology has had to pay crews from the Jamestown S’Klallam tribe to dig out channels and construct diversion dams so that salmon can reenter the Dungeness River. In the Russian River this spring, biologists were forced to rescue baby coho blocked from reaching the ocean by low flows.

The water that remains is often too hot to support salmon and trout. In the Columbia River Basin, where salmon grow stressed at 68 degrees and cease migrating at 74, Al Jazeera reported that some tributaries had warmed to 76 degrees by late July, when a quarter-million sockeye perished. The heat wreaks havoc on the juvenile fish rearing in rivers, too — meaning that the worst impacts might not be felt for years, when wiped-out runs fail to return.

High temperatures also mean more diseases like gill rot, which is as nasty as it sounds. That’s both because stressed-out fish are more susceptible, and because warm waters are more conducive to the spread of pathogens. In the Klamath Basin, elevated temperatures and low flows appear to be at least partly responsible for outbreaks of Ich, a parasite called “the Ebola of salmon.”

Add it all up, and you’ve got fish catastrophes of epic proportions: The near-extinction of the Delta Smelt. Dozens of unprecedented fishing closures in Oregon and Washington. Precipitous declines in California salmon runs. And, of course, the alarming Columbia sockeye die-off. Name a West Coast river, stream or creek, and its finned inhabitants may well be suffering. "We're going to be losing most of our salmon and steelhead if things continue," UC Davis professor emeritus Peter Moyle recently told the LA Times. While Moyle was referring to California's fish, biologists in Oregon and Washington aren't feeling much more confident themselves.

Making the situation even bleaker is that drought doesn’t occur in a vacuum. Many populations have already been pushed near their breaking points by dams, water withdrawals and habitat loss. Throw in a tablespoon of water shortage, and you have the recipe for ecological peril.

To document these unfolding crises, High Country News put together an interactive map depicting a few major trouble spots for the West’s fish. Click on the dots for more information about each situation. If they missed any emergencies (and surely they did), make note of it in the comments, or on social media, so they can add it to the map.

And don’t worry — there’s still time to take up warm-water bass fishing!


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About the Authors & Contributors

Ben Goldfarb

Ben Goldfarb

Ben Goldfarb is a correspondent for High Country News, covering wildlife science, fisheries management and Northwestern resource politics.