Salmon Running in San Leandro Creek
Chinook salmon have recently been spotted running on local waterways around Castro Valley, which is a good sign that the fish habitat is healthy, even if more could be done to protect it, say members of the Friends of San Leandro Creek.
Salmon returning to freshwater streams from the salty ocean are counted every year during the spawning season, which runs from August through January. East Bay Municipal Utility District (EBMUD) reported the salmon run on the Mokelumne River is the most successful return in more than 80 years.
“We’ve been hearing about the big salmon run this year, and we’ve been hearing rumors about seeing them in San Leandro Creek. We have recently spotted them and got photos,” said FSLC member Susan Levenson.
Levenson added that the Chinook in the photo is a cousin of the Rainbow Trout, with the same family and genus, and both are considered salmonids. Both are anadromous fish, meaning they live in fresh and salt water. The California Coastal Chinook is a threatened species and has been off-limits to commercial fishers since the 1990s.
The coloration of the fish in the photo, which is spotty white, shows the damage to the skin from its epic journey.
By the time the exhausted fish reach this final stage of life, they are single-minded in their instinct to spawn, Levenson said. After entering fresh water, they no longer eat and begin physically deteriorating. They are, therefore, not palatable to humans.
It is estimated that only 10 percent of salmon are born in the wild. The rest are born and raised in hatcheries. Hatchery fish are different than their wild cousins because their adipose fins (a small fin near the back of the fish) are clipped.
Members of the FSLC say they are thrilled and somewhat surprised to see these salmon because, in the downtown stretch of the creek, many human-made obstacles (couches, tires, etc.) have substantially blocked the flow of water.
“Seeing the tenacity of these native fish to reach spawning grounds upstream should stress the importance of not using our creek as a dump,” said Levenson. “While humans have inhabited its banks for thousands of years, it is only within the last 150 that our waters were not met with reverence and respect.”
While the return of water levels after last year’s big storms has brought the fish back, Levenson says, salmon are a delicate species and are affected by pollution, water temperature, and stresses.
“Our creek is indeed a natural habitat and should be treated as such,” she says.