Tracking the trout: East Bay biologists, volunteers give spawning fish a leg up/Fish blocked for decades by concrete structure get a lift upstream
February 5, 2019
San Jose Mercury News By Joseph Geha
FREMONT — Over the roar of BART trains speeding along tracks overhead, and the rushing waters of Alameda Creek, it was almost hard to hear the screams of joy let out by a group of people in the waterway when they saw a silvery fish flash along the water line.
It was a sign that the group — a mishmash of fisheries biologists, preservationists and volunteers who waded into the Alameda Creek Flood Control Channel in Fremont Tuesday to catch, tag, and transport steelhead trout upstream — had not come in vain.
“I don’t know if it was a steelhead, it was a sizeable fish,” said Joe Sullivan, the fisheries program director for East Bay Regional Park District, who was waist-high in the channel.
“It skirted up and around our seine,” he said.
For many years, biologists and staffers from the park district, the San Francisco Public Utilities Commission, the nonprofit Alameda Creek Alliance, as well as volunteers, come to this lower creek area every winter when conditions are right for migratory fish spawning.
For decades, the steelhead trout and Chinook salmon trying to complete their instinct-driven trip upstream have been blocked by an impassable concrete structure known as the BART weir, which supports the trains overhead.
When the group catches the fish, both of which are protected under the Endangered Species Act, they can radio tag it to study its migration, and release it upstream where the fish can meet others like it and mate.
“The steelhead have this dramatic, epic lifecycle,” said Jeff Miller, the director of the Alameda Creek Alliance, who was at the creekside.
“They go out, they make this Homeric odyssey around the Pacific. They dodge orcas, they dodge fisherman, they dodge seals and sea lions, then they have to fight their way upstream, against these flows, then we put all these barriers in the way they have to get past,” he said.
“We’re just trying to make it so it’s as accommodating as possible for these migratory fish.”
By midday Tuesday, the group’s haul included just one steelhead trout, but that’s “better than nothing,” Sullivan said.
“It’s just exciting to see them at all come back to the system,” he said. Before 2017, a steelhead hadn’t been spotted in the lower creek since 2008. But for the past three years, they’ve been seen and captured to be relocated.
His hope is that the group will be able to do more captures and relocations this year through March and help boost the trout population upstream.
Within a few years, however, this capturing and relocation may not be necessary as the Alameda County Water District, in conjunction with other public agencies, is investing nearly $70 million in upgrading or replacing rubber dams and building fish ladders and screens to allow the fish to bypass the multiple barriers in the creek.
Fish ladders are essentially a series of pools that step up gradually around a rubber dam or other barrier. The water district has nearly completed a ladder upstream, close to Mission Boulevard. Construction will start this summer on a ladder to get around the BART weir and the rubber dam just beyond it.
Officials said the project will be completed by about spring 2022, after which the trout and salmon should be able to make their way upstream in a more natural fashion.
“It is kind of an interagency, coordinated effort … to ultimately help enhance the population of steelhead,” said Evan Buckland, the water district’s supply supervisor.
Miller said the trout are a good indicator of how healthy the region’s water system is.
“If we can keep the creek clean enough and healthy enough for these fish, we’re doing a good job of taking care of the ecosystem,” he said.
Big showing of American River steelhead excites anglers
February 5, 2019
Stockton Record By Dan Bacher
Large numbers of adult steelhead continue to surge into the American River, the crown jewel of the Sacramento metropolitan area, attracting plenty of anglers in the quest to hook these hard-fighting fish.
The Nimbus Fish Hatchery has trapped a total of 1,843 steelhead to date, the best showing of fish since 2013. These fish include 933 adult males, 826 adult females, 43 half-pounder males, 26 half-pounder females, four wild adult males and 11 wild adult females, reported Greg Ferguson at the Nimbus Fish Hatchery.
“We’ve taken a total of 870,814 eggs to date,” he said. “During our latest spawn on (January 29), we spawned 24 females and 47 males.”
With fish and eggs abundant this year, the hatchery staff foresees no problem meeting its production goal of 430,000 steelhead smolts for release in 2020.
Most of the steelhead showing in the river now are in the seven- to 11-pound. range, with an occasional larger fish showing. The big numbers of steelhead are also drawing crowds of anglers some days to fish the river. That was the case when Doug MacPherson of Sacramento and I fished with Jerry Lampkin of TNG Motor Sports Guide Service in his drift boat from Sailor Bar to Sunrise on January 29.
“We caught and released two adult steelhead while pulling Hot Shots yesterday,” Lampkin said before our trip. “Craig Newton, the owner of Willfish Tackle in Auburn. hooked an eight-pounder, while Jim Palmus landed a 29-incher.”
We had five takedowns from steelhead while back trolling with Hot Shots and throwing Little Cleo spoons, but none of the fish stayed on the hook.
We saw a good number of hook-ups, with some fish landed and many fish lost by the crowd of anglers fishing the river.
That was the biggest amount of anglers on the river that I’ve seen since 2013, an epic year for steelhead. Fishing buddy Rodney Fagundes and I had one of our best trips that January, hooking 14 fish and landing and releasing 9 steelhead between the two of us one day while using plugs and Little Cleos.
With the large numbers of fish now showing, we can expect to see steelhead at least into the end of March and probably into mid-April. Information: (530) 320-0994.
Big surge in Coho salmon population, but the endangered species still needs protection
February 2, 2019
San Francisco Chronicle By Peter Fimrite
The winter rains have caused the biggest surge of coho salmon in a dozen years in the celebrated spawning grounds of western Marin County, one of California’s last great strongholds for the embattled pink fish.
At least 648 coho this winter made their way against the current up meandering, forested Lagunitas Creek and its many tributaries on the northwestern side of Mount Tamalpais, according to a new census by biologists.
The coho run is the largest in the North Bay since the winter of 2006-07 and well above the long-term average of about 500 fish. It’s the sixth-largest run since systematic surveys began in 1996.
The surge of salmon is being credited to habitat restoration efforts for the endangered fish.
“Many organizations and individuals have worked tirelessly for years to improve fish habitat in the creeks of Marin County, and it’s gratifying to see so many salmon returning to those creeks,” said Eric Ettlinger, an aquatic ecologist for the Marin Municipal Water District, which conducted the count with Watershed Stewards Program, National Park Service and the Salmon Protection and Watershed Network.
“After looking at where the population was just a few years ago I’m actually quite happy that it’s grown so much,” he said.
The Lagunitas Creek migration is the largest run of wild coho between Humboldt and Monterey counties — most other river systems contain hatchery-raised fish — and one of the most remarkable. The fish swim 33 miles from the ocean into Tomales Bay and through the redwood- and oak-studded San Geronimo Valley, where half their spawning grounds are in developed areas, including the towns of Forest Knolls, Lagunitas, San Geronimo and Woodacre.
The fish, which can reach lengths of 35 inches and weights up to 36 pounds, swim through people’s backyards, lay eggs and die. Their progeny migrate to the ocean to become adults, returning to the watershed — which includes Devil’s Gulch, Lagunitas, San Geronimo, Nicasio and Olema creeks — at age 3 to repeat the cycle.
The number of coho spawning this year is a 10 percent improvement over their parent’s generation three years ago and a 30 percent gain since their grandparents spawned, Ettlinger said. Generational improvements like this are what conservationists want to see, especially in a species that has long been in decline along the West Coast.
But the coho are far from being out of danger, as a half-eaten carcass in the gravel made clear to Ettlinger recently during a survey of Devil’s Gulch Creek. The bite marks were from a river otter, one of a half dozen that frequent the watershed.
“It looks like this otter ate the heart and internal organs and left the rest,” Ettlinger said, as he cut off the head with a knife and dug into the bone and tissues, which he would later send to a laboratory for analysis.
“River otters wouldn’t be a problem for a healthy population, but they can do real damage to a small population.”
Sea lions and other ocean predators are among the many obstacles facing coho, which are also known as silver salmon.
At least 10,000 coho once swam through the picturesque valley and bred in tributaries that snaked all the way up the side of Mount Tamalpais. Silvers, chinook and other salmonids were once so plentiful that, legend has it, old-timers living along the creek used to spear them from decks overlooking the creek.
The fish continued to thrive despite rampant logging and construction of five major dams, starting in 1873. The spectacular runs finally came to a halt when Seeger Dam, which formed the Nicasio Reservoir, was built in 1961, wiping out the salmon population in Nicasio Creek.All together, the dams blocked 50 percent of the historic spawning habitat in the Lagunitas watershed.
Development, drought and habitat destruction have made things worse. In 2009, only 52 coho returned to spawn in Marin’s creeks and tributaries.
It’s not an isolated problem. Coho now make up only about 1 percent of their historic population along the coasts of California and Oregon. The species in California was listed in 2005 under the U.S. Endangered Species Act.
Biologists say a full coho recovery would require the return of 2,600 fish to the Lagunitas watershed. The best winter since biologists began keeping records in 1994 was 2004-05, when 1,342 coho were counted.
The Lagunitas surveys located a total of 324 egg clusters, known as redds, since the first big rains hit the Bay Area in late November. Since a male and female produce each egg cluster, the number of fish is calculated by doubling the number of redds.
A year ago, Ettlinger counted 110 redds, meaning there were 220 coho in the creek system, but to his astonishment 30,000 young fish, known as smolts, migrated out to the ocean.
“The number was far greater than what people thought this watershed could still produce, so that was very encouraging,” Ettlinger said. “We now know that tens of thousands of young fish can survive and go out to the ocean and that restoration efforts in the watershed are working.”
Chinook salmon also have been seen in the creek, and the steelhead trout run, which peaks in February, is on track to be one of the largest on record, he said.
He credited a community-wide habitat restoration program — including school work parties — and limits on creekside development. Future generations of coho will also benefit from a just completed project by the Salmon Protection and Watershed Network, or SPAWN, to build new floodplains on a mile-long stretch of land next to Samuel P. Taylor State Park where the community of Tocaloma once stood.
Still, only about 2 percent of the coho that left for the ocean over the past two years have returned to spawn, a well-below-average survival rate.
“This is still a critically endangered species,” Ettlinger said. “Salmon are going to be impacted by climate change and ongoing development, so the population could take a nose dive again if we are not very careful.”
It’s been a great year for coho in the Lagunitas Creek watershed and it continues to be great for steelhead
February 1, 2019
Marin Municipal Water District by Eric Ettliinger
The coho spawning season typically runs from November through January, and this year’s run is ending on schedule. Only nine spawned-out coho were seen last week and no coho were seen this week. For the season, surveyors from the Marin Municipal Water District, Watershed Stewards Program, National Park Service, and the Salmon Protection and Watershed Network counted 324 coho redds, making this the sixth-largest run since systematic surveys began in 1996. This run was 10% larger than their parent’s generation, 70% larger than their grandparent’s, and 400% larger than the run of their great-grandparents (back in 2009-10). Such sustained generational growth is a very hopeful sign for the population.
The steelhead run continues to be on track to be one of the largest on record. So far we’ve counted 65 steelhead redds, which is a record for the end of January. February is peak spawning time and we’re hoping that this weekend’s rain will encourage a lot of spawning activity. Spotting these fish isn’t easy, as the photo below shows. Even though they can be up to three feet long, they’re cryptic, prefer to spawn in fast water, and don’t stay on their redds very long. Your best bet for catching a glimpse of one is as they jump or swim through shallow water. If you’re a local, check out the Inkwells at the mouth of San Geronimo Creek on Sunday, when flows should be receding.
Salmon populations may adapt their eggs to survive in degraded rivers
January 31, 2019
Science Daily from University of Southampton
A University of Southampton study suggests that the membrane of salmon eggs may evolve to cope with reduced oxygen levels in rivers, thereby helping their embryos to incubate successfully.
The research, funded by the Environment Agency and published in the journal Royal Society Open Science, has found that differences in the structure of the thin film surrounding a salmon embryo affects its ability to absorb dissolved oxygen from river water.
Atlantic salmon are in decline in their natural habitats and it's thought this is partly due to a reduction in the quality of the water in which they spawn. Sediments washed off the land can starve rivers of oxygen by encouraging more organic matter to grow and by silting up the gravel beds where salmon lay their eggs in nests (redds). The eggs rely on a sufficient flow of oxygen across their membranes to successfully incubate and this latest study examines how the structure of these membranes vary in different salmon populations.
The researchers took a range of measurements from membranes of eggs at a fish farm in Scotland and from conservation hatcheries in four different UK rivers; Dorchart, Tilt, South Tyne and North Tyne. They were chosen for their varying levels of sediment and oxygenation. The results showed membrane thickness, porosity and permeability varied according to each location.
Further tests on eggs in laboratory controlled conditions showed that those with less permeable membranes were less likely to survive low-oxygen conditions -- in other words, the thicker the membrane, the more likely the egg will be starved of oxygen and perish. Conversely, greater permeability means a greater chance of survival.
Lead author Jack Bloomer from Tyne Rivers Trust, who undertook the research while a PhD student in the School of Geography and Environmental Science at the University of Southampton, comments: "Our findings tell us that the permeability of salmon egg membranes differ according to their location and that their structure affects how efficiently they can receive oxygen from the water around them.
"What we can't say for certain yet is whether populations are surviving by evolving a specific membrane structure to suit the particular conditions of the river they are hatching in -- although the evidence points to this as a strong possibility and we hope future studies will provide further evidence."
Professor David Sear, also of Geography and Environmental Science at Southampton, was the lead supervisor on this research working with colleague Professor Paul Kemp of the School of Engineering. Past research by Professor Sear examined how fine sediments from soil erosion, farm run-off, road verges and eroding river banks can accumulate in the nests of Atlantic salmon and other benthic spawning fish.
He comments: "We've previously shown that reduced oxygen supply to the incubating embryo, due to increased fine sediment accumulation in spawning gravels, contributes to the decline in fish numbers in UK and European rivers.
"This new research explores the biological factors that might make populations of Atlantic salmon more or less susceptible to a low oxygen environment. With further work, it could have important implications for the management and rearing of salmon populations."