Amazing Smolt and Faint Glimmers of Salmon Hope
Photo courtesy of the Monterey Bay Salmon and Trout Project
By Mark C Anderson, August 5, 2024
Salmon smolts do amazing things. Full stop.
Even after 16 years studying salmon and similar species, partly through his role as director of the Monterey Bay Salmon and Trout Project (MBSTP), Ben Harris still marvels at their dramatic feats.
“As they migrate from freshwater to the ocean, the smolt go through an amazing transformation.Their kidneys change! They go from seeking salt to being able to repel it! Their scales harden!” he says. “It’s a much, much bigger change than human puberty. It’s really quite amazing.”
He’s got a point.
When exposed to salt water, normal freshwater fish’s cells, and the fish, shrivel and die. Smolts develop specialized chloride cells in their gills to tolerate saltwater.
Meanwhile they transition from darker shades that hide them in shadowy rivers to silver that camouflages them in the sea. Rapid size increases also happen. Sensitivity to environmental cues like temperature, river flow and day length helps them time the migration. Their tails grow thinner and longer, and their movements get more streamlined and coordinated with schools that aid survival.
The whole time they’re covering as many as 12 miles a day, and—vitally—imprinting on the chemical composition of their native stream, which allows them to navigate back to the same location years later to spawn.
Those adaptations prove impressive. But they’re also not enough.
In addition to nature’s obstacle course of predation and starvation, huge human-created hurdles await, including dams and reservoirs—20 of them in the Central Valley system alone—which have taken away hundreds of miles of traditional habitat.
Climate disruption adds another challenge, with several years of drought conditions leaving the rivers warmer and drier than ever before.
Smolt can’t swim 12 inches, let alone 12 miles, in dry river beds. And they don’t survive well in warm water, especially when filled with predators like invasive bass.
This is where the idea of trucking smolts from up river to the ocean was born, to help improve survivability.
The Monterey Bay Fisheries Trust has outlined the challenges facing West Coast salmon in depth, reporting on the closure of 2023’s salmon season, “Disaster Can Be…Good.”
We also highlighted solutions like the “Three Hs”: improved habitat, hatcheries and hydrology” as advocated by the Golden State Salmon Association, one of the most active and coordinated groups working to change water policy to protect and restore salmon here. (More on the hatcheries in a second.)
Smolt being released into the Monterey Bay. Photo courtesy of the Monterey Bay Salmon and Trout Project
The aforementioned Salmon and Trout Project ranks among their champions, and has been fulfilling its mission to “restore and resuscitate” the native salmon and steelhead runs of the Monterey Bay Area since 1976. The MBSTP’s activities include captive broodstock programs, smolt releases, juvenile stranding rescues and education outreach.
Its work came into renewed focus of late with two recent releases of Central Valley-raised smolt on either side of Monterey Bay.
Harris helped manage the June 2 release of thousands from Monterey’s commercial wharf and a June 3 unloading of thousands more in Santa Cruz. That came in support of California Department of Fish & Wildlife (CDFW) and its chinook salmon rehab efforts, including the Ocean Salmon Enhancement program.
While the Project navigated permits and coastal access, the CDFW trucked in smolt from the Mokelumne River Hatchery near Clements, California, using specially designed tanker trailers carrying smolt in Mokelumne River water—now well imprinted on the fish since they hatched. That water is also lightly salinated to simulate the brackish estuary waters they’d encounter naturally to ease the juveniles’ transformation.
The trailers carry more than fish on the 170-mile ride. They carry hopes of boosting the recovery of a calamitous salmon fishery and overall stock abundance by preventing mortalities in rivers compromised by diversion to ag fields.
It also comes as the fishery itself has been closed for two years in a row, while fishermen still wait on the disaster relief payments from 2023.
“The fish that MBSTP releases will go a long way toward restoring an ocean salmon fishery for the Monterey Bay region and the entire state,” Harris writes in the most recent MBSTP newsletter, observing each fish is individually tagged, and analysis of previous tagging data shows that the ocean release of juvenile salmon benefits fisheries all along the coast. “After living at sea for two years, many of the fish released by MBSTP will be full-grown adult Chinook, fish so prized by anglers they long ago earned the common name ‘king’ salmon.”
The Trust’s Director, Melissa Mahoney, just participated in a June 27 panel on KQED Forum called “Bay Area Fisheries Working Against the Tide of Shortened or Canceled Seasons.” (Part of the discussion covered how hatcheries have helped the Chinook hang on, even as hatchery politics have gotten increasingly complex.)
San Francisco Bay fisherman/fishmonger and author of The Sea Forager's Guide to the Northern California Coast, Kirk Lombard, also took part. “There’s no replacing king salmon,” he said. “It’s our beautiful prize of…California.”
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Given the smolts’ amazing adaptability, it makes poetic sense that the folks at MBSTP have endured harrowing challenges themselves.
Its headquarters and hatchery near Davenport narrowly survived the 1989 Loma Prieta Earthquake, multiple winter floods over decades, the 2009 Lockheed Fire and 2020 CZU Lightning Complex wildfire that burned through MBSTP’s Kingfisher Flats hatchery.
“Trying to save an endangered species is challenging enough,” Harris says. “It gets more compelling when you think about overcoming wildfire, government shutdowns and drought. We’ve endured and we’re still here.”
As the Trust outlines in the 2023 salmon season closure report, there are a number of actions salmon-conscious citizens can take.
Those include truly understanding how many factors contribute to population health (well beyond fishing) and supporting restoration with the likes of MBSTP and Golden Gate Salmon Association.
It also means seeking out other local fish (and hitting the dock sales and devoutly Monterey Bay-based fish purveyors like H&H Fresh Fish in the Santa Cruz Harbor or Sea Harvest and Woodward Marine in Moss Landing.
“As far as replacing king salmon,” Lombard told KQED, adding him and his wife’s community-supported fishery includes recipes to make things like sablefish incredible on the plate. “We’re really focusing on what we have: halibut, black cod, rockfish.”
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While the salmon situation remains bleak, Harris doesn’t see surrender as an option.
He offers two key things to consider.
One, a collapse hasn’t happened yet.
“There are a lot of projected models, and with natural and human systems the capacity for change is where things can happen,” he says. “With the conservation of habitat, and emissions under control, we can have a logarithmic recovery trajectory. There is a cause for optimism on that aspect. We can change our ways and do a lot more good in less time.”
Besides, Harris adds, look at progress made in revising “our forefathers’ mistakes” when it came to gold mining, early ag development, reservoir management—and most dramatically—a revolutionary dam removal at the Northern California-Oregon border.
“Some say it’s hopeless, but look at the Klamath-Trinity River System!” he says. “Salmon have had a rough 200 years at the hands of humans. It doesn’t mean it has to continue.”
Two, even if he and his team agreed there’s no rationale for optimism—they definitely do not—they wouldn’t quit anyway.
“We can give up on this species or struggle to save it,” he says. “I’d rather struggle and come up short than give up.”