(CN) – The population of spring-run Chinook salmon has ebbed to the point where fish advocates, Native Americans and environmentalists are warning near-term extinction is a real possibility.
Last week, divers conducted the annual fish population survey on an 80-mile stretch of the Salmon River that winds its way near the California-Oregon border, and found the number of spring-run Chinook salmon was just 110. That figure represents the second lowest number in the 20 years of data collection.
“We knew that fish diseases practically wiped out juvenile populations in recent years,” said Nat Pennington, a board member of the Salmon River Restoration Council and the Klamath Riverkeeper. “Still it’s a shockingly low number of spring salmon.”
There has only been one time, in 2005, when fewer fish were counted: divers only managed to count 90 fish that year. Historically, hundreds of thousands of fish made the run from the Pacific Ocean upstream into the Salmon River, a 20-mile tributary of the much larger Klamath River that winds through Siskiyou County.
In 2011, the same teams of scuba divers managed to count 1,600 fish, but numbers have been on a steady, precipitous decline since.
While Pennington noted disease as a substantial factor, a recent study by the University of California, Davis, identified another culprit: climate change.
“Climate change is likely the greatest threat to the long-term persistence of spring-run Chinook salmon due to anticipated increases in summer water temperatures and decreases in availability of cold-water refuges for holding adults in summer,” scientists Peter B. Moyle, Robert Lusardi and Patrick Samuel wrote in the study titled “Salmon, Steelhead, and Trout in California.”
The study makes the case that rising temperatures make the removal of dams that block fish access to the colder headwaters of the Klamath River all the more imperative.
But other environmentalists argue a different kind of action is needed: The recognition of spring-run Chinook as a distinct species from its fall-run counterpart.
“If we can prove to Western scientists what the Karuk People have known since creation, we can finally get federal and state agencies to create a spring Chinook recovery plan for the Klamath River,” said Josh Saxon, a council member of the Karuk Tribe.
Previous efforts to list the spring-run Chinook under the Endangered Species Act have sputtered because of questions of whether the fish is genetically different from the fall-run Chinook salmon. The fall-run salmon enjoys better population numbers but is still threatened.
But without protection, the spring-run variety is likely to disappear within 50 years, the UC Davis scientists say.
““I brought my son Taydin to check out the big Salmon River survey event for the first time this year,” said Karuk tribal member Kenneth Brink. “These fish are his future, but when we see incredibly low runs like this you worry if there will be any left.”
The Yurok and Hoopa Tribes, with reservations situated along the Klamath River, received their lowest federal allotment for salmon in several years.