California, Florida fish mortality pinned to drought, climate change

The California Department of Fish and Wildlife said that “nearly all” of the endangered winter-run Chinook salmon’s juveniles might not make it through the season, according to The Sacramento Bee.


The publication reported Wednesday that a final blow, after two years of “severe mortality during the last drought,” would risk the extinction of the species — even though the agency has hauled millions of the Chinook salmon to Bay Area waters as a precaution.

Triple-digit temperatures have plagued the West, killing hundreds of people in the last major heat wave. The severe conditions have exacerbated the climate-driven “megadrought,” leading to less water and less streamflow.

“We were talking about [drought response] in January, hoping weather conditions would improve, but developing a game plan in case they didn’t,” Brett Galyean, project leader for Coleman and Livingston Stone national fish hatcheries, said in a U.S. Fish and Wildlife Service Pacific Southwest Region news release earlier this month. “We were able to release about 11.8 million fall-run Chinook salmon before river conditions turned poor because we planned ahead and used the tools in our toolbox.”

Using special trucks, the California Department of Fish and Wildlife relocated almost 17 million fall-run Chinook salmon earlier this year because of dry conditions.

Residents near California’s lower Klamath River have witnessed the change in their ecosystems firsthand. 

As toxic algal blooms in the Klamath basin’s main lank threaten the also-endangered suckerfish a month earlier than “normal,” water is in short supply and dead juvenile chinook salmon are found every day.

In addition, extra flows of water from Upper Klamath Lake that mitigate outbreaks of a parasitic disease that proliferates when the river is low are not coming this year and the parasite is killing thousands of juvenile salmon.


Sixty-three percent of fish caught in research traps near the river’s mouth have been found dead. 

“When I first started this job 23 years ago, extinction was never a part of the conversation,” Jamie Holt, lead fisheries technician for the Yurok Tribe, said of the salmon earlier this month. “If we have another year like we’re seeing now, extinction is what we’re talking about.”

Yet issues for the United States’ fish are bicoastal, as the effects of climate change continue to grip the nation. 

In Florida’s Tampa Bay and elsewhere, fish kills from red tide – and the resulting smell and potential respiratory irritation – have prompted officials to call for government aid.

NPR reported Tuesday that the Pinellas County solid waste division said around 600 tons of dead sea life have been collected throughout the county since late June.

“Red tide is destroying ecosystems in the Tampa Bay Area,” Florida’s Agriculture Commissioner Nikki Fried told The Orlando Sentinel on Monday. “Our water quality must come before politics.”

While the massive fish kills are nothing new and algal blooms are natural, NPR noted that blooms are rarely seen in the summer and the Tampa Bay area. 

Warmer waters, a change in salinity, more carbon dioxide, changes in rainfall and sea level rise all help to provide a hospitable environment for the blooms, according to the Environmental Protection Agency.

The reason for the fish kills is under debate – though Tropical Storm Elsa recently lashed Florida shores.


Scientists are looking into whether rapidly spreading red tide blooms are connected to the state’s decision to pump 215 million gallons of polluted wastewater into Tampa Bay last spring.

A Florida Fish and Wildlife Conservation Commission spokeswoman stated last week that the Piney Point discharge did not cause red tide in Tampa Bay but it may have made it worse.

The Associated Press contributed to this report.