Despite an increase in the number of Chinook salmon in California this year, some fishers are worried that methods to truck and barge hatchery fish will lead to long-term problems for the restoration of ecosystems and fisheries.
by Alastair Bland
LAST SPRING, THE outlook for California’s 2017 Chinook salmon fishing season was dire. Years of drought had taken a toll on the rivers where salmon spawn, reducing them to lukewarm trickles. As a result, the number of adult fish was seriously depleted, reported scientists with the Pacific Fishery Management Council. They estimated just 230,000 Sacramento River Chinook to be swimming in the ocean off the central California coast. In good years, local fishers catch at least that many salmon while hundreds of thousands more of the fish swim upriver to spawn.
As fishers braced for a disappointing season, they found quite the opposite – thanks, it turns out, to some changes in fisheries management practices. But while this should be good news, some fishers are concerned there could be negative implications for long-term efforts to restore river ecosystems.
An Abundant Season
This season there were salmon everywhere, with massive schools gathered along the coast, feasting on krill and anchovies in the midst of sea lions, birds, humpback whales and, very quickly, an armada of fishing boats.
Due to the forecast of poor salmon numbers, regulators imposed unusually strict restrictions on commercial anglers but not on recreational fishers. For the latter, the spring and summer of 2017 wound up being one of the best fishing seasons in recent memory. Jared Davis, operator of the Salty Lady charter fishing boat in Sausalito, says his boat’s customers – anglers who pay about $100 a day for the chance to catch coveted Chinook salmon – caught their two-fish daily limits on almost every trip. Not once, he says, did his boat return to harbor empty-handed after a day of fishing.
“That hasn’t happened in years,” says Davis, who described the fishing in 2017 as “phenomenal.”
Trent Slate, captain of the party boat Bite Me, based in San Rafael, reported a similarly productive 2017 season, with clients catching all the salmon they legally could bring home every day for weeks on end.
“It was spectacular – they were calling for a very low fish count, and it was nothing like that,” Slate says.
The successful fishing caught fishers by surprise, especially after the drought conditions and sloppy management of reservoir outflows killed millions of fertilized salmon eggs in 2014 and 2015. There was every reason to expect a generational gap in the adult salmon population.
So, what happened? Where did the Chinook salmon of 2017 come from?
It turns out that the California Department of Fish and Wildlife, which operates several fish hatcheries in the Central Valley, modified its practices in key ways that dramatically increased the survival rates of young fish, which are released into the wild at several months of age.
For one thing, the timing of the releases was adjusted – specifically, they were made less predictable in a successful effort to reduce losses to predators, such as birds and striped bass. Historically, releases of young salmon – which are often trucked to the lower Sacramento-San Joaquin River Delta or San Francisco Bay to move them past dangerous irrigation pumps in the Delta – would occur over a period of several days. Bill Smith, the manager of the Department of Fish and Wildlife’s Mokelumne River Hatchery, says that after two or three days of pumping fish from tanker trucks into the water, most of the finger-sized salmon were being eaten by gatherings of predators.
“It was like ringing a dinner bell – there would be tons of striped bass waiting for the fish,” he says.
So in the spring of 2016, his hatchery changed things up, releasing 5 million salmon smolts on a two-days-on-five-days-off regime that Smith says seems to have effectively foiled the predators.
John McManus, executive director of the Golden Gate Salmon Association, which advocates for habitat restoration and improved fishery management, says the new release protocol could end up being a key strategy for ensuring abundant salmon populations in the future.
“This is big, really big, because this is a measure that we can easily scale up,” he says. “Without a doubt, millions of fish benefitted from going to two days on, five days off.”
The same release schedule was used in 2017. This, combined with heavy rainfall and high springtime river flows that probably helped naturally born salmon successfully escape the Sacramento River system, will likely mean good fishing next year.
“Without a doubt, we’re going to have a lot of two-year-old fish in the ocean in 2018,” says McManus, whose organization has helped fund the salmon transport programs that release the fish downstream of the Delta.
Fishery managers are experimenting with other improvements over existing release strategies for their young fish. For example, the Mokelumne hatchery has been sending experimental batches of young salmon to San Francisco Bay for release in a barge instead of in trucks. The barged fish are kept in tanks of recirculated river water, and the slow boat journey seems to be less stressful for them than highway transport. Tagging experiments involving tiny coded wires inserted into young salmon’s noses before release have shown that the barged fish survive to become adults at a higher rate than trucked salmon. Tag recovery data also indicates that nearly all juvenile salmon released into the river system, especially in dry years, die before becoming adults – probably somewhere in the Delta.
“So far, the barging experiment is outperforming all our other releases,” Smith says.
Fish Without a River
While enhanced efforts to produce salmon in hatcheries are proving successful, Smith warns that they don’t solve the underlying issues that have made the Sacramento River – once an astoundingly productive Chinook salmon river – such a hostile environment for small fish.
Frequent water shortages, driven by human demand, have compromised upstream spawning habitat, while in the middle reaches of the Sacramento River system, farmers have converted critical floodplain habitat, where fish find food and refuge, into orchards and fields. In the southern Delta, powerful pumps that send large volumes of water to farms and cities have contributed to the decline of numerous native fish species, according to scientists. The pumps sometimes reverse river flows so that young salmon trying to reach the sea end up lost in remote backwaters instead, where they are often eaten by predators. In fact, research has shown that few naturally born salmon escape the river system most years.
“Barging is just a band-aid,” Smith says. “The river still has to flow in the right direction.”
He says “a fine line” separates solutions to the problems plaguing the state’s salmon fishery and the forces – mainly related to human water use – that threaten it.
“It’s a double-edged sword,” he says. “If you promote the barging as the way to have a productive fishery, the water agencies might feel they can take more water. We have to keep in mind that the barging doesn’t make a healthy river again.”
Davis, skipper of the Salty Lady, likewise worries that artificially maintaining the Sacramento’s Chinook could undermine long-term river conservation goals.
“There are water districts that use the Sacramento’s water who are likely to say that we’ve figured out how to produce salmon without water, and they might say, ‘Hey, we can take all the water we want now,’” he says.
Commercial fisher Mike McHenry is more optimistic. He owns the purse-seining squid boat that has been used since 2012 to barge young salmon to San Francisco Bay.
“I see a bright future here,” he says. “Hopefully, we can now have our salmon, and [the farmers] can have their water, with some restrictions on how much they take.”
Originally appeared on NewsDeeply.com