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Health, Science, Environment
California salmon are back, but for how long?
Life is pretty boring if you’re a salmon growing up in the Nimbus Fish Hatchery. After being incubated in a tray, you spend six months in a plastic tub surrounded by 70,000 fish just like you. Then, it’s graduation day. You’ll be scooped into a tanker truck and dumped into the Sacramento River. But for now there’s nothing to do but eat, and the only thing you see all day are the people who feed you, like D.J. Gervin.
Gervin is a technician with the California Department of Fish and Game, and he feeds a lot of fish at work each day – four million of them. Gervin’s job is to get the fish up to size, which means 10 feedings a day. He tosses handfuls of pellets that look like coffee grounds into long plastic troughs filled with inch-long baby fish. He says you have to watch your fish.
"You just observe how they react – if you walk up to ‘em and they’re skitzin’ away from you, they’re pretty full. But other times you throw in a little bit of feed, and they’ll run right at you."
The Nimbus Hatchery sits at the base of a dam 15 miles east of Sacramento. It was created for California fishermen when the dam was built in 1955 – to make up for the salmon that lost their spawning grounds.
It wasn’t supposed to be this way. In Gold Rush times, two million Chinook spawned and died each year in Central Valley rivers. When California’s dams went up in the ‘40s, ‘50s and ‘60s, they destroyed 70% percentof the flowing freshwater habitat wild salmon used to spawn.
"The promise was made at that point by the dam builders, by the water people, they promised the fishermen that we can do better than nature," says Peter Moyle, a fisheries biologist at UC Davis. "It doesn’t matter that the dams are there because we can build hatcheries, and these hatcheries will do so well that they’ll more than sustain the fishery. And that’s a promise that has really not been kept.
Overfishing, water diversions, agricultural runoff, and urban pollution took their toll. So officials decided to engineer the salmon’s survival. Stuffed with synthetic bio-feed, vaccinated against disease, and implanted with a tracking tag, the modern hatchery system leaves nothing to chance – not even birth.
"You can see our spawning pans up here,' says Nimbus Hatchery manager Bob Burks. "These are actually what we spawn fish into, they’re just a plastic pan … and that’s where these eggs go into." Burks holds up a spaghetti strainer he says he got from Target.
"That female is spawned into a colander so what’s called the ovarian fluid goes out and we can rinse the eggs. At that point there’s a male next to there," Burks continues. "We actually slide the boy across and expel milk, that is sperm, into the eggs."
But growing up in a hatchery doesn’t guarantee you’ll survive long enough to see that plastic pan. Let’s say you’re six months old now – a toddler in salmon years. And you’re sent from your well-fed, climate-controlled life into, well, basically the Pacific Ocean. There are salmon sharks there, and other fish competing for your food. It’s dangerous and confusing, and your survival instincts have been dumbed down by swimming around in the only home you’ve ever known: a big plastic tub.
Sad to say, scientists say you have a one percent chance of reaching adulthood and returning to spawn as a three-year-old. A decade ago, more than a million fall-run salmon just like you were caught in the ocean or spawned upstream. Those numbers dropped to 41,000 by 2009.
Biologist Peter Moyle says even though the salmon have been replenished, the die-off is going to happen again. He said salmon have been going out to sea, hitting bad ocean conditions, and not coming back.
Ironically, Moyle says, California’s network of hatcheries is part of the problem. Today, they pump out more than 90 percent of the fall-run Chinook in the ocean. In other words, it would be hard to find a salmon that wasn’t farm-raised. It’s likely that most of the fish we think are wild salmon are at most two generations removed from a hatchery.
The mass production has led to a gene pool in which fish from one stream are indistinguishable from fish in another. That makes the whole pool more vulnerable when, say, there’s not enough food in one part of the ocean.
"These are not very good wild fish," Moyle says. "They go out to sea and they do the same thing. Well, if conditions are bad where they happen to be, they all die."
But that’s not all. Moyle says hatchery fish have less experience avoiding predators at a young age than wild salmon do, and their brains are less developed, too. Wild salmon aren’t hatched on a schedule, and their diversity makes them more resilient.
But in today’s fishery, does it really matter whether the salmon are wild or not?
“I don’t really think fishermen care," says Jim Anderson, a second-generation salmon fisherman out of Pillar Point Harbor in Half Moon Bay. "I think fishermen are looking for a nice, healthy fish that they can enjoy and catch and eat. I think that’s what the fishermen want."
Like other skippers here, his income was devastated when the season was shut down for three years. The prospect of pulling in some fat, healthy Chinook, again, is a huge relief. But no one knows how long it will last, and another bad season could push plenty of fishermen, suppliers and processors out of the business for good.
According to Anderson more of the boats are falling by the wayside; a lot of the fishermen that used to be fishermen aren’t.
A week before the season opener on May 1, fishermen got busy sanding and painting their boats, loading the gear they’ll need to catch the salmon. When they do, their catch will be advertised as “wild.” Will consumers mind that they probably weren’t born on a riverbed? Anderson doesn’t think so.
"By the time that they’ve left the hatchery, gone through the gauntlet to get back in the ocean, have survived in the ocean for two, three, four, or five years, and then returned back to the hatchery, that is as wild a fish and as natural a fish as you’re ever going to need to have," says Anderson.
The spring and winter Chinook runs are already listed under the Endangered Species Act, but fishery managers have yet to admit that the hatcheries’ boom times masked a disturbing decline in wild fall-run salmon, too. Seen through history’s lens, questions of where fish were hatched may start to matter. The future of this ancient species depends on it.