As Alaskans turn their attention to yet another forecast of a low return of sockeye salmon to the waters lapping at the shore of the state’s largest city, Canadian scientists are out with a new examination of food competition between salmon at sea.
It would appear to contain nothing but bad news for the shrinking population of the most popular fish in the most popular fishery in the most popular area of the h49th state.
Pink salmon – “humpies” as Alaskans tend to call them – are now far and away the most abundant salmon in the Gulf of Alaska, and the study would indicate they compete for food with sockeye in a big way.
“The highest diet overlap across the North Pacific was between pink and sockeye (46.6 percent), followed by chum and pink (31.8 percent), and chum and sockeye (30.9 percent),” according to the study – “Meta-Analysis of Salmon Trophic Ecology Reveals Spatial and Interspecies Dynamics Across the North Pacific Ocean” – published in the journal Frontiers in Marine Science.
Food competition between salmon at sea has become an increasing topic of discussion among scientists pondering whether the North Pacific has reached its salmon carrying capacity.
Their conclusion has been universally accepted by other fisheries scientists, and so, too, their observation that about 70 percent of the fish are humpies.
While working on an update to that 2018 estimate last summer, Ruggerone messaged that “2019 was exceptional too. Nothing compares to the back-to-back large (pink) runs in ’18 and ’19.”
Three years ago, Ruggerone told the American Fisheries Society that “there is growing evidence that this high abundance, especially pink salmon, is impacting the offshore ecosystem of the North Pacific and Bering Sea.
“This impact may be contributing to the decline of higher trophic species of salmon….”
Sockeye (red), coho (silver) and Chinook (king) salmon are chief among those higher trophic species, and returns of those species have for years been spiraling downward in Cook Inlet, the waterway that stabs into the state’s gut like a thumb poking at Alaska’s urban core.
Correlation is not causation, as Bill Templin, the head of fisheries research for the Alaska Department of Fish and Game has repeatedly observed, but the correlation between big Alaska humpy runs and sockeye declines in Cook Inlet has become dramatic.
Commercial catches in the Inlet averaged 4.4 million sockeyes per year in the 1980s, according to Fish and Game data. The average fell to 3 million for the first decade of the new millennium. And though there looked for a brief period to be a turnaround to this trend coming in the 2010s, the decade ended with a somewhat deceptive average of 2.4 million.
One good year
The Inlet in 2011 witnessed an unusual and unexplained return of about a third more sockeye than forecast by state biologists. That led to a harvest of 5.3 million of fish in 2011, the largest harvest in the past 20-plus years and the fourth largest in Inlet history.
The only harvests larger came in a brief period between 1985 and 1993 when the Inlet was at the peak of sockeye productivity. If the 2011 catch is removed from the decadal count for the 2010s and the other nine years are averaged, the annual catch in the Inlet drops to just a hair over 2 million.
Some commercial fishermen contend sport and personal-use dipnet catches have cut into the commercial harvest since the ’80s, but those catches don’t begin to account for the decline that largely coincides with booming pink salmon runs.
In 1993, for the first time in state or territorial history, Alaska found itself nearing an unheard of harvest of 200 million salmon only to fall 7 million short.
Two years later, however, the catch would top 200 million, and that feat would be repeated again in 1999, 2007 2013, 2015, 2017 and 2019. It is worth noting all those years have something in common; they end in odd numbers.
Odd years are when pink salmon are generally dominant in the North Pacific, and Canadian scientists who published a peer-reviewed paper in the Transactions of the American Fisheries Society in 2014 indicated that dominance is increasing, though they weren’t sure exactly why.
University of Washington researchers, meanwhile, have identified even-year and odd-year pinks as genetically distinct populations. They are so different that odd-year pinks spawning in creeks far apart are more alike than the odd-year and even-year pinks that spawn in the same stream.
Pinks spend only 18 months at sea, and in Alaska the fish spawned in one odd year and destined to return in the next odd year swamp their even year relatives.
Alaska commercial fishermen harvested 59.4 million pinks in 2020, an even year, according to state records. That amounted to about 46 percent of the 129.1 million harvested in 2019, an odd-numbered year.
Some fisheries biologists theorize that odd-year pinks have become so prolific and have such a large impact on the Pacific ecosystem that they leave in their wake food shortages that suppress the productivity of even-year pinks.
The theory is hard to prove, but if true could have big implications for sockeyes, cohos and kings which spend years at sea instead of months as pinks do.
The hand of man
Alaska salmon hatcheries have played a major role in helping create this plentitude of pinks. The state record catch of 280 million salmon in 2013 was 80 percent pinks and 40 percent of those – or about 88 million humpies – were directly attributed to hatchery production.
How many more of the fish might have been linked to hatchery-origin parents who decided to spawn wild upon their return to Alaska is unknown, but hatchery strays have been found in most of the streams in Prince William Sound, now the humpy and hatchery capital of Alaska.
A variety of studies conducted in streams along the North American West Coast have concluded that hatchery-origin salmon that chose to spawn in the wild produce fewer young than wild spawners, but overall production is inherently a numbers game.
If streams that generally have small numbers of wild spawners attract hatchery strays that become an addition to the wild number, any extra production is a plus up to the point the hatchery fish interfere with the wild fish.
State fishery researchers are still trying to sort out the dynamics of this situation, but overall, Sam Rabung, the state’s Director of Commercial Fisheries, said they have yet to find any indication the hatchery pinks have hurt wild-pink numbers.
And it goes without saying that the Sound has become an industrial-style, pink-salmon factory. The Sound’s portion of that record 2013 catch totaled more than 91 million pinks, according to Fish and Game.
That is more than three times the harvest of the 26.2 million pinks, chums, sockeyes, coho and Chinook caught in all the waters of Alaska in 1975.
In a wide-ranging discussion earlier this month, Rabung pointed to the private, non-profit (PNP) hatcheries run by commercial fishermen in the Sound as a huge fishery management success and criticized those – Ruggerone and Irvine among them – who have suggested the production of hatchery salmon is altering the Pacific ecosystem.
University of Alaska scientist Alan Springer joined by colleagues in Australia and researcher Gus van Vliet in Juneau in 2018 went so far as to blame an over-population of pinks for starving shearwaters – birds that winter in Australia and spend their summers in the Aleutian Islands where they compete with pinks for food.
“Pink salmon in the North Pacific Ocean have flourished since the 1970s with growth in wild populations augmented by rising hatchery production,” that team of researchers wrote in a peer-reviewed study published in the Proceedings of the National Academy of Sciences of the United States of America. “As their abundance has grown, so too has evidence that they are having important effects on other species and on ocean ecosystems.”
Rabung echoed that view and argued that declines in Gulf of Alaska sockeye, coho and Chinook populations appear to be due to the nearshore deaths of juveniles rather than losses due to competition with pinks at sea.
There is no doubt that the ecosystem of North Pacific is, as Templin pointed out to the Fish Board, a mind-boggling tangle of interactions between hundreds of species of life from phytoplankton, bacteria and microzooplankton at the bottom of the food pyramid to humans and whales at the top.
But there is also no doubt that the state agency charged with managing wild fish has long looked at the hatchery issue through the wrong end of the telescope for decades given a state constitutional mandate to utilize and conserve “all natural resources belonging to the state, including land and waters, for the maximum benefit of its people.”
Hatchery salmon are not a natural resource; they are a manmade resource. And thus the onus on the Department of Fish and Game should be to show that hatchery production doesn’t harm wild fish rather than the other way around.
The way the system has worked to date is tantamount to the U.S. Army Corps of Engineers permitting development of the controversial Pebble Mine unless someone can prove it will pollute the Iliamna Lake watershed. That is, of course, impossible to prove because it is possible Pebble mining could be conducted in a way that doesn’t pollute.
Pebble has been subjected to an exhaustive process of environmental impact studies to try to determine whether mining can be done without significant harm to other resources. Alaska salmon hatcheries have never been required to file a single environmental impact statement, though there is no doubt they amount to nature tampering in a significant way.
On average, Templin told the Board of Fish, “private, no-profit hatcheries (now) account for a third of the (state’s) commercial harvest.”
With big harvests comes big money, which helps to buy political influence. And the hatcheries in the state that banned fish farming in 1990 have gained big influence.
They are now the economic bread of life in the Sound where the historic catch from 1951 to 1979 averaged but 3 million fish per year.
That was destined to change radically after Alaska voters approved more than $56 million in bonds for hatcheries and the state began pouring what would eventually amount to more than $210 million into Fish and Game’s Fisheries Research and Enhancement Division (FRED) with an eye toward supplementing “wild stocks through production until a total goal of 100 million fish was reached,” according to a review completed for the Alaska Senate’s Special Committee on Domestic and International Commercial Fisheries in the early 1990s.
FRED was eliminated at about the same time, and most of its hatcheries were transferred to the PNPs. The official Fish and Game history now describes what happened this way:
The report to the Senate prepared by University of Alaska Fairbanks economists outlining the status of FRED hatcheries paints a different picture of why the facilities were essentially given to the PNPs.
“As part of this review, a cost/benefit analysis of the state’s enhancement program for salmon was performed,” it said. “The main results are that the additional producer’s surplus generated by the pink and sockeye hatchery programs are estimated to be less than the costs of running these programs.”
Simply put, the hatcheries were a money loser for the state. The problem was solved by turning them over to the PNPs, allowing the PNPs to assess a fee on commercial fishermen to help cover hatchery costs, and when that failed to move the hatcheries into the black, permitting them to harvest and sell salmon for “cost-recovery” purposes.
This private trafficking in what is still legally described as a “common property,” public resource has been hugely successful. It boosted the annual harvest in the Sound from 3 million salmon per year to 45 million salmon per year, creating an industry most recently valued at $125 million per year.
No attempt has ever been made to determine what, if anything, this might have cost other fisheries, although researchers have been warning since the 1990s that there could be costs.
Then University of Alaska researcher Richard Cooney and the National Oceanic and Atmospheric Administration’s Richard Brodeur in 1998 modeled salmon foraging in the Gulf of Alaska and reported that the annual volume of food consumed by Sound pinks “rose from less than 100,000 metric tons prior to 1976 to more than 300,000 metric tons after 1988 when hatchery production began dominating adult returns. Food demand was distributed nearly equally between survivors and nonsurvivors, and most of the food consumption occurred in the oceanic rather than coastal environments.”
They went on to warn of possible “serious consequences for both wild and hatchery populations.”
There are no indications Sound pinks ever suffered any consequences, and possible consequences for Inlet sockeye, coho and king salmon have not been studied.
But scientists looking for lingering damage from the Exxon Valdez oil spill in the Sound four years ago stumbled on evidence linking Sound hatcheries to declines in Copper River sockeye salmon.
“All sockeye salmon stocks examined exhibited a downward trend in productivity with increasing PWS hatchery pink salmon returns,” the researchers wrote in a peer-reviewed study published at PLOS One. “While there was considerable variation in sockeye salmon productivity across the low- and mid-range of hatchery returns (0–30 million), productivity was particularly impacted at higher levels of hatchery returns.
“We do not know if possible deleterious interactions between hatchery pink salmon and wild sockeye salmon in this study are from predation or competition, or whether they occur in nearshore or offshore areas. Pink salmon feeding may cause a general depletion of prey availability that could impact sockeye salmon without tight spatial overlap of these two species. In this regard, the apparent impact to sockeye productivity may reflect a general increase in pink salmon abundance across the northeast Pacific rather than increased abundance of hatchery pink salmon to PWS in particular.”
Somehow the Forest Service overlooked the fact the Copper River and its salmon are environmental resources in the Chugach National Forest when conducting the Main Bay EIS.
Three of the scientists involved in Exxon Valdez study were Alaska state fisheries biologists, but the state agency has officially ignored the study. Rabung suggested it is just as likely the Sound hatcheries boost the production of other species of salmon, given that pink salmon fry are prey for many other fish, as it is that they depress the populations of other species of salmon.
State fisheries biologists have stayed largely silent on the question of food competition since the PLOS One study. Discussions of the topic have been largely left to Canadian, Pacific Northwest and international scientists.
Eighty-year-old Canadian Dick Beamish, a salmon research icon, has been spearheading new efforts to learn more about the life of salmon in the ocean, which up until this time has been largely a black box.
That there is a problem in the ocean has been well documented by Canadian David Welch and his associates at Kintama Research Services in British Columbia.
In a peer-reviewed study published in Fish and Fisheries late last year, they documented a 65 percent, coast-wide decline in Chinook numbers that showed fish in wild Alaska streams struggling as badly as the salmon of the much-dammed Columbia River.
“The abundance of salmon in the North Pacific has reached record levels,” the Kintama researchers conceded “However, most of the increase is in the two lowest valued species (pinks and chums) in far northern regions, at least in part due to ocean ranching.
“In contrast, essentially all West coast North American Chinook populations including Alaska are now performing poorly with dramatically reduced productivity.”
Little was learned before Parnell’s successor, former Gov. Bill Walker largely defunded the research. Walker was indebted to commercial fishing interests for his election.
A state report issued in March of this year indicated that a good share of the funds earmarked for king-salmon research were spent on social science studies aimed at acquiring local and traditional knowledge about subsistence harvests.
Subsistence is the Alaska term for catching fish for food. Subsistence users were another key Walker constituency.
Among the subsistence findings in the state report was the discovery that Cordova-based commercial fishermen are becoming slightly better at keeping track of what is called “home pack,” the fish they keep to eat rather than sell.
“In 2003, the survey estimate was 1,119 Chinook salmon retained from commercial harvests for home use, 64 percent higher than the 681 kings reported on harvest tickets,” the report said. “In 2014, the Chinook Salmon Research Initiative study year, household surveys estimated 790 Chinook salmon home pack and harvest tickets reported 490 Chinook, a 61 percent difference.”
Commercially caught kings disappearing without being recorded on so-called “fish tickets” has been the subject of much debate in the state with kings in short supply in recent years, but those harvests – even if the most widely speculative estimates are used – do not appear big enough to be a game-changer.
The real problem would appear to be where Kintama found it: at sea. And the real meaning of what is going on there is hard to tell.
It could be, as Ruggerone has suggested, that Alaska – a world superpower in the production of hatchery fish – has set up a system that essentially trades high-value sockeye, coho and king salmon for low-value humpies.
Or it could be that global warming has so altered the North Pacific prey base that the ocean is now better suited for ranching pink salmon than for any other purpose.
Or it could be that it’s all really nothing but a blip on the radar screen of global time being viewed by people who judge the ecological functions of the world on the basis of the human lifespan.
Still, there is no denying the 1.5 billion or so little salmon Alaska hatcheries dump in the ocean each year amounts to nature tampering on a massive scale.
Alaska Department of Fish and Game data