Home Biologist Endangered salmon return to Marin Creek after a decade away

Endangered salmon return to Marin Creek after a decade away


National Park Service biologists say they have counted the highest number of young coho salmon in Pine Gulch Creek on the Point Reyes National Seashore in more than 20 years – an encouraging sign that the fish once thriving, but now on the way of disappearance, could return to its former stronghold after more than a decade of absence.

National Park Service biologists reported finding 300 juvenile salmon in the creek this summer, which they say is the highest number since it began regularly monitoring the creek in 2001.

“Those that survive through summer and winter will migrate out to sea next spring as smolts,” park service staff wrote in an update this month. “I hope many will return as adults to keep the coho population alive on Pine Gulch.”

This is the second year in a row that park staff have found coho salmon in the creek after they disappeared more than a decade ago. The park service says historical accounts indicate the 7-mile creek that follows Highway 1 and empties into Bolinas Lagoon was one of many strongholds of salmon along the Marin coast. By the 1970s, seasonal dams, water diversions, and the major drought of 1976-77 had disappeared from most courses at Pine Gulch Creek and others throughout the county.

Coho salmon were not found again in Pine Gulch Creek until 2001. However, the population declined between 2006 and 2009 due to low numbers and environmental pressures. No more salmon returned after the winter of 2008-2009.

It wasn’t until the winter of 2020-2021 that park biologists came across the carcass of a coho salmon laying next to its eggs. When they returned in July, the researchers found a baby coho swimming in the same spot.

Coho salmon have a three-year life cycle. After hatching, young salmon spawn in their freshwater homes for about a year and a half before swimming out to the ocean. After another year and a half, they return to the stream where they were born to spawn and then die. Park staff said it’s likely that salmon that have spawned in Pine Gulch Creek the past two winters were born in Lagunitas Creek or Redwood Creek but strayed into Pine Gulch.

While park staff have said the return of salmon to Pine Gulch Creek is encouraging, expectations about the long-term viability of this migration should be tempered.

“For coho to regularly recolonize Pine Gulch would require regional salmonid migrations to remain strong, increasing the likelihood of more fish straying into this watershed,” the staff wrote. “Yet, if climatic conditions remain favorable for rearing juveniles and high survival in the ocean, we may well see members of this cohort return to spawn at Pine Gulch again in three years.”

Conditions at Pine Gulch Creek have improved through a partnership between local farmers and the Marin Resource Conservation District. As part of the program, three farms in Bolinas have agreed to forgo their summer diversions of water from the creek starting in 2018.

In return, the farmers received permission to store water in four ponds during the peak winter months. The extra water in the creek benefits young breeding coho when flows can drop to dangerously low levels in dry years.

“These fish now have their own water rights,” said district executive director Nancy Scolari. “Our hope is that it works. It’s encouraging to see that there are numbers coming back.

Peter Martinelli’s Fresh Run Farm is one of three participating farmers and said the project has brought mutual benefits to both the fish as well as the fruits and vegetables he grows. Before the project, a dry winter meant he would probably not be able to pump water in the summer to irrigate his crops. Martinelli said the ponds now provide a safer source of water during dry spells.

Growing up seeing coho in the creek as a child, Martinelli said he always wanted to see them come back in large numbers.

“Hopefully that’s the basis for building a track here,” Martinelli said.