Greenland’s new pink salmon colonies/Arctic Science 2024
The all-conquering pink salmon
While Alaska fisheries biologists have been fretting about whether pink salmon straying from the state’s ocean-farming ranches could damage the genetics of wild, 49th-state pinks, the feral progeny of the species has been busy staging a takeover of northern latitude waters around the hemisphere, according to a new study.
The study by scientists from Canada, Russia, Norway, the United Kingdom, the United States, Ireland and Finland also warns that the nations of the world need to address “the invasion potential of pink salmon (and) interactions among pink salmon and other species” as the salmon Alaskans call “humpies” continue to expand.
Whether the humpy explosion is a good thing or a bad thing is an individual value judgment. Though the Scandinavian countries and the UK are now treating pink salmon as invasive species that need to be controlled, there are those on the other side of the hemisphere who believe newly arrived pinks should instead be treated as a renewable and harvestable resource.
She conceded as “understandable” Norway’s official policy of trapping humpies in-river before they spawn to prevent competition with”vulnerable Atlantic salmon, sea trout, and Arctic char populations that underpin Norway’s wild fisheries,” but said this ignores a “commercial opportunity.”
“A new series of research trials financed by the Norwegian Seafood Research Fund point to a more proactive, and possibly profitable, solution: targeted marine capture,” she wrote. “In three separate trials this summer…fishermen deployed various net techniques, including modified gillnets, land seines and purse seines, to intercept pink salmon offshore.
“The early results are promising: high-quality catch, low bycatch of protected native species and effective gear designs that reduce mortality rates when releasing unwanted fish.”
In her glass-half-full view of the situation, a new commercial fishery could “be a rare case where industry, science and environmental protection aren’t at odds, but aligned. It might even offer the north Norwegian fleet a future beyond decline.”
There is only one problem with this rosy view: New fisheries invariably create new constituencies that lobby for the continuance and often the expansion of those fisheries.
The Alaska experience
If you want to know what happens, just ask any angry, commercial salmon fisherman in Cook Inlet.
For those unfamiliar with Cook Inlet, it is the 180-mile-long bay that slashes into the underbelly of the 49th state to lap at the shores of Anchorage, the state’s largest city and the anchor for the sprawling Anchorage metropolitan area that is home to half to two-thirds of the Alaska population.
These people comprise what Kenai commercial fishermen consider the urban horde trying to seize the Inlet sockeye, Chinook and coho salmon that the commercial fishing industry took away from the Native Alaska population in the late 1800s and considered its own for more than 100 years.
Then came the development of sport fisheries for Chinook, the fish Alaskans called “king salmon,” on the Kenai River; the start of a tourism industry built on the backs of those and other Kenai salmon; a federal “subsistence” law dictating that feeding rural Alaskans with wild resources was a government priority; and a subsequent demand from urban Alaskans that their “food security” should be treated in the same as subsistence through “personal use” fisheries.
All of this created constituencies wanting a share of the fish that commercial fishermen long-believed belonged to them, and “fish wars” have now raged in the Inlet for decades. But this is far from the only place in the 49th state where shifting fishery constituencies have altered the management of Alaska salmon.
Enter the lowly humpy.
This was not by accident. It was thanks in part to significant production from the large hatchery operations controlled by commercial fishing interests and the efforts of the Alaska Department of Fish and Game to manage wild pink salmon for maximum sustained yield – MSY as it is called – despite indications that the high-volume production of low-value humpies is now suppressing the production of high-value Chinook, coho and sockeye salmon in some areas of the state.
Part of the problem here is that salmon management success has come to be measured in volume rather than value, and Alaska has become a volume monster. Where a statewide, all-species harvest of 100 million salmon was once considered a good season for commercial fishermen, it is now considered a bad season.
The new standard for good hovers around an all-species harvest close to 200 million, especially so in odd-numbered years when humpies rule.
Returns of pinks in even-numbered years are significantly smaller, although – thanks largely to the state hatcheries – they now approach the range of the odd-year, average harvests of 70.8 million back in the 1980s. Over the past 10 years, even-year harvests of humpies have averaged 50.8 million.
This is 18.2 million more than the even-year average for the 10 years prior to 2009, but still almost 20 million shy of the 70 million salmon processors asked for in 2010. They that year penned an “Open Letter to Alaska Hatcheries” noting the decadal averages harvests of a mere 32.6 million hatchery pinks “in even years and 55.9 million in odd years – in both cases about 40 percent of total (statewide) pink returns.
“We would like production to increase to 70 million in both even and odd years over the next five years, which would bring hatchery production to roughly 50 percent of that total.”
Despite the best efforts of Prince William Sound hatchery operators, who have played a major role in dictating salmon management in Alaska since the turn of the century, the processors never quite saw their wish fulfilled.
Even-year and odd-year harvests never reached equilibrium, and ocean-farmed hatchery pinks never reached the goal of making up 50 percent of the pink harvest. But hatchery and wild pinks combined did become the far and away most common salmon in the Pacific.
Pink salmon, almost all from Alaska and Russia, are now calculated to make up 60 to 70 percent of adult, Pacific salmon in any given year, with researchers reporting the species “more abundant now than ever.”
A humpy bonanza
The annual average harvest of Alaska pink salmon over the past 10 years, counting both even and odd harvests, stands at 71.3 million, slightly above what those Seattle-based processors wanted in 2010.
Unfortunately, the low-value of pinks – the jug wine of the salmon business – and the variability of harvests, which makes it hard to plan for efficient processing-plant staffing, hasn’t worked out all that well for those humpy-hungry processors.
While they were pushing Alaska’s ocean-salmon ranchers to produce large volumes of small salmon best put into cans or pouches, net-pen farmers in Norway, Chile, Scotland and elsewhere were steadily upping the production of the big, fat, net-pen farmed Atlantic salmon consumers wanted.
NOK 124.7 billion works out to approximatly $12.3 billion. The known value of Alaska’s 2025 salmon harvest is, at this time, is $541 million, according to the state. But that figure is based only on what commercial salmon fishermen were paid for the fish they caught, and the value of this Alaska harvest increases after the fish are processed.
The so-called “first wholesale value” of salmon moving into the retail product stream is usually somewhere around three times the value of the salmon fishermen sold to processors. So the Alaska harvest was probably worth somewhere around $1.6 billion or somewhat more than an eighth of the value of the salmon produced by Norway.
Norway is a small Scandinavian country with a world-leading commercial salmon industry. Alaska is a U.S. state four to five times larger than Norway with a commercial salmon fishing business now in chaos.
Climate change
Some of this can be blamed on climate change, even though the 49th state has benefited greatly from a warming North Pacific Ocean.
The only problem was that the big increase in numbers was largely due to the harvest of those smallish – 3- to 3.5-pound average weight – and low-value pinks now worth only about 75 cents per fish, and especially due to market floods of pinks in odd-numbered years.
Odd-year and even-year pinks are genetically distinct fish, according to scientists, and the odd-year fish appear to have developed to best take advantage of warmer ocean waters. There are now more pinks in the North Pacific Ocean than at any time in human history, and thanks (or not) to humans, they are flourishing in the Great Lakes and expanding in the Atlantic Ocean.
The ICES study describes them as “invading the Barents Sea and Atlantic Ocean across Europe and into eastern North America from the introduced Russian source population. In Europe, and especially in Russia, Norway, and Finland, the numbers of pink salmon present in rivers in odd-numbered years has increased rapidly since 2013, with surprisingly large increases with every subsequent generation beginning in 2015.
“Successful spawning has now been documented in Norway, northern Finland, northern Scotland, and western Iceland. In northern Norway, the abundance of pink salmon far outnumbered native Atlantic salmon in 2021 and likely also in 2023.”
As noted above, those countries are treating pinks as an invasive species and trying to control their numbers, but as is often the case with invasive species, control is not easy.
“Pink salmon have several attributes that make them successful colonizers, and their rapid range expansions emphasize their adaptive potential,” the study notes. “The high relative abundance of pink salmon and a 10 percent straying rate in wild populations combined with short freshwater residency and generation times allow pink salmon to access, establish, and adapt quickly to new environments.”
Pinks have now begun showing up in streams on the East Coast of North America with a suggestion of new colonies there, and they have proven an interesting experiment in genetic adaptability in the Great Lakes, to which they were accidentally introduced in 1956.
That introduction came in Lake Superior, the most western of the five Great Lakes, and within 23 years, comprising 12 generations of humpies, the fish were resident in all of the lakes and rapidly developing new behaviors.
“Within 18 years (9 generations) in these freshwater ecosystems, some pink salmon in the Great Lakes began spawning as 3-year-olds as a potential response to cold temperatures and/or low productivity, a major deviation from their usual 2-year and saltwater-dependent life history,” the ICEs study says.
“In the time since their introduction, these pink salmon have been reported to be spawning at any time between one and four years of age. Pink salmon in the Great Lakes had low genetic diversity following the introduction, but exhibited rapid genetic adaptations, which made them physiologically better suited to their new environment.
“Similarly, established odd-year pink salmon stocks in their introduced range in northwest Russia have been documented to display adaptive changes compared to their source population, including shifts in genetic character, phenological adaptations, altered morphology, and increased body weight and fecundity. Taken together, this evidence suggests that pink salmon are well-suited to colonizing new habitats both within and outside their native range.
“Despite their potential as colonizers and history of successful introductions, it is only recently that global concern about the impacts of pink salmon on species and ecosystems has greatly increased. In the North Pacific Ocean, during recent years of naturally higher pink salmon abundances that were amplified by industrial-scale hatchery releases, there has been evidence of widespread impacts of pink salmon on other salmon species and top-down effects of pink salmon on numerous pelagic species, food webs, and ecosystem function.”
An Alaska debate
The official, state of Alaska position on those “top-down effects” is that the correlation between increases in pink salmon due to both hatchery production and MSY management cannot be proven to have caused declines in other salmon species or shrinkage in the size of those salmon.
This is true if one applies the criminal court standard of proof beyond a shadow of a doubt.
But it is equally true that it cannot be proven beyond a shadow of doubt that the efforts of Alaska to maximize the production of pink slamon hasn’t caused declines in the size and number of sockeye, coho and especially Chinook salmon, the biggest of the species.
All along the West Coast, from the dammed rivers of Oregon and Washington to the still wild watersheds of Alaska, kings have been in a 50-year decline, and this decline just happens to coincide with the boom in Alaska pink salmon numbers.
The Russians, who witnessed Alaska hatchery success with pinks and copied it, are also a big producer of pinks, but their hatchery fish primarily use the pastures of the far eastern Gulf of Alaska and the Bering Sea.
Alaska pinks stick to the central and eastern Gulf where they compete for food with and sometimes dine on other species of salmon that originate from streams and rivers in the Pacific Northwest, Canada and Alaska.
Here it must be recognized that salmon at sea live and die in a war zone where they are never sure where their next meal will come from or who might kill them.
If you’re a young Chinook struggling to survive, your worst nightmare is running into a big, hungry school of pink salmon. And the same applies to a young pink in a school of young pinks encountering a predatory king or coho salmon.
Beneath the ocean surface, lurks a violent, fish-eat-fish world where the vast majority of all species of salmon – 90 percent or more – are destined to die. The salmon that makes it back to its natal stream to spawn is a rarity even in the best of years.
And the numbers game now gives plentiful and adaptable humpies a long-term survival advantage in the same way the numbers gave our species an advantage over the more than 20 hominin species that once roamed the planet.
The best known of those are the Neanderthals, and the science now shows that as the population of homo sapiens grew, the population of homo neanderthalensis shrunk.
Studies clearly show some interbred with homo sapiens until their offspring were so fully absorbed by our species that only genetic fingerprints remain to show their link to all non-Africans. Other Neanderthals appear to have held out as isolated populations until their lack of genetic diversity, due to inbreeding in their shrinking populations, rendered them incapable of adjusting to shifting natural, social and cultural environments.
Over the course of tens of thousands of years, this led to the Neanderthals’ extinction.
There is, as yet, no real sign that humpies could similarly absorb and render extinct other species of salmon, but there is a hint of this possibility.
In the Great Lakes, humpies have now found to be breeding with Chinooks to produce cross-breeds known as “pinooks.” And researchers in Norway have successfully crossed pink salmon with Atlantic salmon.
Atlantic salmon have been struggling throughout their range for decades, and most populations are now considered threatened if not endangered.
That constitutes a global population of Atlantic salmon less than 70 percent the size of the 5-million-plus sockeye salmon that returned to Alaska’s Kenai River last year. And the Kenai is but one Alaska rivers that sees massive returns of sockeye or pink salmon.
Kenai kings are, however, in a decline as are kings in many Alaska streams and rivers. The Deshka River, a tributary to the Susitna River just north of Alaska’s largest city, was reguarly welcoming returns of 14,000 to 24,000 kings per year in the early 2010s.
Fewer than 1,700 returned last year, and the year before that the fewer than 3,500 Chinook that came back were lost among a flood of 44,000 pinks. This presents prime conditions for possible interbreeding, but to date, there have been no pinooks reported anywhere in the Pacific.
And even if regular hybridization were to start this year, it would likely take tens of thousands of years or more for the ever-growing population of pink salmon to absorb the ever-shrinking population of Chinook.
This could be considered either good news or bad news, depending on your personal views of the various species of salmon. When a large run of pinks hit Puget Sound in August, Seattle residents didn’t hesitate to flock to the beaches to meet them in the same way Alaskans who scoff at pinks swarm to the Kenai to net sockeyes or catch them with hook and line.
