The annual return of endangered coho salmon to West Marin’s Lagunitas Watershed to spawn is an annual dance of nature — only this year it seems some unusual visitors have cut in on that dance.
Biologists working among the West Marin watersheds that compose one of California’s last spawning grounds for coho have spotted two other types of salmon rarely — if ever — seen in the area.
The observers witnessed and photographed pairs of chum and pink salmon — also known as humpback salmon for their bowed backs — frolicking in the streams. Both types of fish are common in areas farther north from Oregon to Alaska but are foreigners in West Marin.
"We started getting species we really haven’t seen here before," Todd Steiner, the director of Turtle Island Restoration Network who has worked on fish issues in the area for more than two decades, said.
Steiner said he has spotted only one chum salmon in the creeks in his 25 years in West Marin. He pointed out a female chum salmon swimming beneath the Shafter Bridge near the Leo Cronin Fish Viewing Area. The male of the pair had already left and the female was guarding her nest of eggs — her tail rubbed white from sweeping sand from the nest.
"This is pretty far outside their range," Steiner observed, pressing his eyes to a pair of binoculars. "It is very unusual."
A week ago, wildlife managers with the Marin Municipal Water District spotted a pink salmon in one of the creeks. Steiner said it was the first time he’d ever heard of one visiting the watershed.
"Who knows what else could be in play," Steiner theorized of the unusual appearances, "climate change, temperatures changing, food sources moving around and these animals following their food sources."
Steiner said chum salmon have a much different life pattern than the coho salmon, whose diminishing numbers return to the watershed each winter. Once hatched, juvenile coho will spend the entire year in the creeks before making their way to the ocean. Chum salmon, on the other hand, will begin their trek to the sea soon after hatching.
The appearance of the foreign fish added a note of excitement to the beginning of the spawning season, which draws legions of visitors to the creeks scouring for any sign of the nesting fish.
"It’s probably one of the most incredible things is to see the fish when they’re jumping, and climbing up," said Liz Baylis, a San Rafael resident who stopped by the area to look for fish. "And to think how far they’ve come, coming all the way from the sea."
Steiner said the unpredictability of nature is ultimately a gift — the chance to see something new and unexpected, he said, is what makes forays outside interesting.
"Whenever I take people out into nature, it’s like we don’t know what we’re going to see," Steiner said. "And if we did know for sure, that would be boring."