August M
Rivers are the lifeblood of the American West, keeping fragile ecosystems alive against shifting weather. When those waters change, wildlife suffers.
Now, a major West Coast waterway is witnessing an alarming crisis that has left scientists completely blindsided, reports The Independent.
A deadly outbreak
Something is killing Chinook salmon in the Klamath River. Running through California and Oregon, the waterway is seeing a massive surge of a microscopic parasite called Ceratonova shasta, according to a report by The Independent. It latches onto fish gills and causes severe bleeding. Humans are not at risk.
The speed of the infection has caught researchers off guard. Usually, heavily infected fish die quickly. But in this outbreak, biologists are finding dead salmon filled with mature parasites that are ready to multiply and infect new hosts.
“It’s unusual that there’s such a severe reaction and the parasite has still been able to mature,” Sascha Hallett, an assistant professor at Oregon State University, told SFGATE.
Perfect warm storm
Nature is fueling the problem. Record-low snowpacks mean less cold meltwater is flowing into the Klamath, leaving the river shallow and warm. The Independent reported that these temperatures stress the salmon and weaken their immune systems while helping the parasite multiply.
The numbers paint a grim picture. The U.S. Fish and Wildlife Service announced that nearly half of the 700 young salmon they tested came back positive for the infection.
To help, California officials released 675,000 healthy young salmon in May. Agency spokesperson Peter Tira told SFGATE the release was timed right before regional storms arrived to cool the river.
Uncertainty ahead
But the fish may have run into trouble anyway. Oregon State University microbiologist Stephen Atkinson told SFGATE that the juveniles lingered in the area for a few days before swimming to sea, exposing them to the spores. Atkinson also detected a second parasite sickening the fish.
This outbreak arrives during a massive shift. The office of California Governor Gavin Newsom previously announced the removal of four major dams to restore 400 miles of salmon habitat.
With the dams gone, the river is transitioning, and the parasite is pushing further north than ever. “We just don’t have the complete picture yet,” Hallett told SFGATE, noting that experts will continue monitoring the river.
Sources: The Independent, SFGATE, U.S. Fish and Wildlife Service, Oregon State University, Office of the California Governor
