Fears of some state fisheries biologists that turning Prince William Sound into one big salmon ranch might threaten the remaining wild stocks there gained some weight this week. Oregon researchers reported in the journal Proceedings of the National Academy of Sciences that the genes of steelhead trout -- a close relative -- appear easily altered in a hatchery.
Mark Christie, lead researcher on the work done at Oregon State University, painted a portrait of "evolution at warp speed" in the sterile, environmentally controlled trays of a hatchery.
Whether the 11,000-square-mile Sound -- smeared by the Exxon Valdez oil spill in 1989 -- should be home to piscatorial wolves or dogs has been a subject of debate for years now between the Alaska Department of Fish and Game and the Prince William Sound Aquaculture Association (PWSAA).
"Our obligation to manage wild (salmon) stocks in Prince William Sound is very challenged at current levels of population," state scientists warned in an April 2010 memorandum. "Department … studies suggest that at current (hatchery) production levels, hatchery salmon straying may pose an unacceptable risk to wild salmon stocks."
Essentially every wild salmon-spawning stream in the Sound has now been infiltrated by straying hatchery salmon. Contrary to popular perception, salmon don't all return to their natal streams, and pink salmon -- one of the major species ranched in the Sound -- are famous for straying. Pinks made the news this fall when a huge school of them showed up unexpectedly in the Pacific Northwest.
The fish "are outdoing themselves this year with record numbers of the salmon being counted at the lower Columbia river's Bonneville Dam," The Columbia Basin Bulletin reported. "State fishery officials aren't aware of any resident pink salmon populations in the Columbia River basin," which is to say there aren't any. Or at least there weren't. Pink salmon are clearly trying to change that.
"A total of 979 pink salmon have been counted as they climb up and over the Bonneville's fish ladders," the Bulletin reported in September. "That easily surpasses the previous high count." By the time the strays finally quit coming, almost 4,000 of them had gone up that fish ladder.
No one knows how many hatchery salmon have strayed and invaded Prince William Sound creeks and streams, but most biologists seem of the opinion that it would be fair to say tens of thousands or more. To which, the PWSAA -- a private, nonprofit in the business of producing money despite the "nonprofit" label -- says so what? In a February letter to Fish and Game, the organization, which again wants to increase the number of immature salmon it dumps in the ocean, scoffed at state concerns.
"PWSAC addressed the Department's concerns regarding the most recent estimates of hatchery origin salmon straying into adjacent streams in our July 7, 2010 letter," wrote David Reggiani, the company's general manager. "In return, the department acknowledged that there is no research that clearly demonstrates genetic impact from Alaska pink salmon enhancement programs like PWSAC conducts. This then leaves the concern of any potential impact to the genetic integrity of PWS wild stocks to theoretical speculation."
Like fish out of water
The speculation has now become a lot less theoretical.
After a genetic analysis of Hood River steelhead going back 20 years, Christie concluded that unintentional natural selection -- what he called "domestication selection" -- was producing hatchery fish less adapted than their wild cousins for survival in the wild. Obviously, this is a bigger problem for species like steelhead, which are raised to smolt stage in the hatchery before being dumped in the sea. Pink salmon, on the other hand, are deposited in the ocean as fingerlings.
One theory on the steelhead is that overcrowding of fingerlings in rearing pens as they are raised to smolt size selects for fish that tolerate extreme overcrowding, not those with the best attributes to survive in the wild. But there could be any variety of things going on.
The hatchery is a climate-controlled facility. The flow of water over eggs and alevins is stable, as is the temperature of that water. No fish are lost due to flooding or frozen river beds. "In the wild, up to 85 percent of the eggs do not survive to the fry state," notes a U.S. Fish and Wildlife Service publication promoting a federal hatchery. "Hatchery loss to the same fry stage is about 10 percent, potentially greatly increasing the number of returning adults."
Maybe on both counts. It is a well-known fact that the returns from hatchery ranching projects vary widely, and there has been speculation that this might be due to hatchery-spawned fish being less-well equipped than their wild cousins to compete in the violent oceanic ecosystem. The vast majority of both hatchery-spawned and wild fish die in the stomachs of other fish, seabirds or marine mammals.
It would be tempting to say it's a fish-eat-fish world were there not so many other critters also eating fish, or simply catching them, killing them, and dumping them back in the ocean, as is the case with the trawlers that strip-mine the North Pacific in order to serve up fish sticks or frozen fish fillets.
Meanwhile, it can’t be ignored that improvements in survival, from 85 percent dead to 90 percent living, amounts to a whole lot of tinkering with natural selection. Genetics used to be thought of a whole lot like salmon homing. Plants and animals were created with a specific genetic blueprint, and they stuck to it. New research has shown it isn't quite that simple.
Scientists have discovered that early in the development of some organisms, the environment has the ability to activate certain genes. Or not. A gene that isn't "turned on" is like an electric light in a room with the power off; it's useless. It could well be that in the controlled environment of the hatchery, genes that prepare salmon for survival in the wild aren't activated.
End-goal for hatcheries: Environment or economy?
Christie didn't deal with the issue of strays in his paper, but he was moved to suggest that the data on the genetic changes spawned by hatcheries does raise questions about the idea of trying to save wild salmon runs by supplementing them with hatchery fish. The goal of the PWSAC, of course, has never been to save wild salmon runs but to save a segment of the Alaska economy. In that, the organization has been a huge success.
"PWSAC played a critical role in the recent economic recovery of the Alaska salmon industry," claimed a study released this spring. "Since 2006, PWSAC has produced 1 in 4 of Alaska's commercially caught pink salmon. Large harvests of PWSAC pinks have provided the industry with the volume and economies of scale needed to fulfill demand."
Over the five years from 1995 to 2010, the Sound produced 43 percent of the pink salmon caught in Alaska, and nearly all of them were hatchery fish. Commercial fishermen might be adamantly opposed to fish farms, but they do love their hatcheries. It’s no surprise; hatcheries put money in the pockets of Alaska commercial fishermen. In fact, hatcheries once produced so many pink salmon they blew up the market for the fish. Just eight years ago, commercial fishermen and hatcheries appealed to the state for permission to strip pink salmon roe -- the most valuable part of the fish -- and dump the carcasses.
Thankfully, that practice now appears to have been relegated to the dust bin of Alaska's history of wasteful fishing activities. The PWSAC-funded economic study of salmon noted a "shift from canned to frozen production had a major impact on the wholesale value of pink salmon products, which in turn increased the ex-vessel price for pinks. The wholesale price of frozen pinks climbed 37 percent to $1.27 per pound." At that price, carcasses become worth saving either to sell as frozen fillets or in cans.
That, coupled with a national and international salmon marketing plan funded with significant financial help from both state and federal governments, has encouraged, again according to the PWSAC-backed economic study, "more health-conscious consumers ... to (buy) wild salmon to meet their needs for alternative sources of protein.
"Consumers are more aware of the environmental impact of their spending choices -- the state's emphasis on responsible and sustainable resource management satisfies these requirements."
The state goes to considerable lengths to promote its "wild fish" -- even if many Alaska salmon might more accurately be considered "free range" than wild. "Why Alaska Seafood?" asks the website of the Alaska Seafood Marketing Institute, a significantly government funded organization promoting the sale of Alaska fish.
"Wild-caught Alaska salmon, whitefish varieties and shellfish mature at a natural pace, and swim freely in the pristine waters off Alaska's rugged 34,000-mile coastline."
Swim freely they do, though tens of millions of them are bred, hatched and initially reared in hatcheries before being turned loose in the sea. It has been, overall, a good thing. The value of the Alaska salmon catch has grown steadily from a value of about $1.3 billion in 2004 to $1.7 billion last year. It has been an especially good thing for the Sound and its fishermen. The salmon harvest there historically averaged less than 10 million fish per year. It averaged more than 45 million a year -- a more than four-fold increase -- over the past decade thanks to the hatcheries.
Sound fishermen might like to whine about how man's tampering with the environment, in the form of the Exxon Valdez oil spill, damaged them. But they have been a huge beneficiary of man's tampering with the environment, in the form of the massive fish spills from the PWSAC hatcheries that each year return a bounty of salmon. This has been good for the fishermen. This has been good for the communities that depend on the fishermen. Christie's research, however, raises this question:
Is it also good for the salmon?
The Chicken Littles in the environmental community, and there is no shortage there, would reflexively say "no." But the PWSAC has a point when it claims "that there is no research that clearly demonstrates genetic impact," because there is no such research. And there might never be. What Christie's research would appear to show, above all else, is that salmon are a species able to readily adapt to their environment.
Put them in a hatchery, and the genetic signature of fish best adapted to hatchery life quickly shows. There’s no reason to believe this wouldn't work exactly the same in the wild. Put the fish back in the wild, and in a generation or two the genetic signature of the fish best adapted to life in the wild would again show itself. There have been no indications that natural returns of salmon to Sound streams have fallen because of the infiltration of hatchery fish. If anything, they appear to have increased.
Christie's work might suggest raising biological escapement goals for wild streams, on the premise that the progeny of the hatchery fish will survive in lower numbers in the wild than the progeny of the truly wild fish. But then again, no one knows when the genetic changes in these salmonids take place. Is it possible the eggs spawned from a hatchery fish in a wild stream become the makings of a wild fish as they go through the winter of development in the gravel of that stream?
It's an interesting question and one worth further scientific study, because in Alaska a bargain has been struck. Hatcheries are now viable businesses helping to support key segments of the commercial fishing industry, a key state business. As William Smoker, a respected federal scientist and university professor once observed, "I don't think we've done any damage to the ecosystem in Prince William Sound. It's pretty hard to detect any ecological effect. ...The main thing we have done is create an economy."
Before hatcheries arrived in the Sound, there weren’t enough salmon to prosecute a fishery there in one out of every five summers. Every fifth summer was -- for lack of a better comparison -- an Exxon Valdez summer, with fishermen ordered to stay in port.
"You can't have an economy based on salmon fishing if every fifth summer you have to shut down," Smoker said.
No, you can't. The hatcheries in the Sound, it could be argued, might not have saved any fish, but they sure saved a fishery. Looked at that way, Christie's research looks a little different. The wolf is a wonderful animal, but the natural environment -- even under the best of circumstances -- won't support all that many of them. The dog, well, the dog didn't earn the sobriquet "man's best friend" because of its rarity, that's for sure.
Contact Craig Medred at craig(at)alaskadispatch.com.