Near-extinct salmon show promising return to Bay Area Creek


Researchers from the Marin Municipal Water District said significant rainfall late last year eased drought conditions and may have helped boost the coho salmon population at Lagunitas Creek, a 24-mile creek. miles into Marin County where the fish spawn every winter.

Eric Ettlinger, an ecologist with the agency, told the Marin Independent Journal that the creek has seen one of the largest salmon migrations in a decade and fish surveyors have found 330 nests of coho eggs – the second highest number recorded during this period. Three hundred and seventy nests were counted during the winter months of late 2018 and early 2019.

“For the public, it was an incredible year because [salmon] were all over the watershed,” Ettlinger told the outlet. “People were seeing them at popular spots like Devil’s Gulch and Leo T. Cronin Fish Viewing Area and spawning over a long period of time. They said they hadn’t seen so many salmon in years and this year was the best sighting they had ever seen.

The news comes after Salmon Protection and Watershed Network (SPAWN) biologist Ayano Hayes spotted the shiny red tail of a coho salmon in the nearby waters of Montezuma Creek in Forest Knolls earlier this year. Hayes told SFGATE it was the first recorded sighting of the species since 2004.

Although Hayes considers the species’ return to Lagunitas Creek encouraging, he said the “sudden drought” that followed heavy rains in January and February left him worried about the survival of emerging fry or fry. small salmon just beginning to leave their gravel nest.

Coho salmon have been in “severe decline” since the mid-20th century, according to the California Department of Fish and Wildlife, and sandbanks blocking the fish due to drought conditions have been a major factor in their demise.

However, subsequent light rains that fell in March and April gave the species respite, replenishing parts of the waterway and allowing younger salmon to move to safer sections of the stream downstream amid continued risk. such as warming temperatures.

“Right now we’re still seeing schools of juveniles feeding in pools and scurrying all over streams in the watershed, more than I’ve seen in years,” Hayes said in an email. .

An image of a coho salmon jumping over a dam in Isaaquah, Washington.

Kevin Schäfer/Getty Images

While thousands of coho salmon once visited the Bay Area, only a few hundred return each year, according to SPAWN. Hayes said biologists carefully observe the quality and temperature of the stream’s water – conditions to which the salmon are “extremely sensitive”.

But for now, “it’s reassuring to see these numbers of juveniles because it gives a greater chance of survival for this cohort,” said Hayes, adding that the rain also helped 22,000 smolt-stage salmon migrate to the ocean. This was the second highest number of emigration populations since SPAWN began monitoring it in 2006.

“We’ve been very lucky this year with the rain just at the right time,” said Hayes. “We won’t see these fish return until they are adults ready to spawn in the winter of 2023-24, but hopefully ocean conditions are favorable and this cohort will continue to grow with each return.”


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