“Our results from Upper Russian Lake, together with previous research (done on Kodiak Island) suggest dramatic, multi-centennial periods of lower salmon abundance in multiple systems across a wide area of the northern Gulf of Alaska,” they reported in the peer-reviewed Journal of Paleolimnology in 2018. “Though reduced freshwater carrying capacity from increased glacial meltwater input may have played a role in the Upper Russian Lake salmon decline, the common anomaly in other clearwater lakes suggests that altered ocean conditions are a contributing factor.

“Further research into the ocean environment during these times may shed light on how climate influences salmon production in the ocean. As a working hypothesis, the climate conditions that led to significant first-millennium AD glacial advances in this part of the Kenai Peninsula (cold and/or wet conditions), may have created unfavorable ocean conditions during critical times during the marine phase of these stocks of Gulf of Alaska sockeye. Interestingly, these conditions were different from those during glacial advances in the Little Ice Age, a time for which most available sediment core data from Alaskan sites suggests high salmon abundance (including the Russian).

“Future climate projections and management strategies should focus on understanding how climate regimes not only impact prey availability for salmon at sea, but also influence local conditions for spawners and juveniles.”

The issue of “prey availability for salmon at sea” gets incredibly complex because it depends not just on the volume of prey but the competition for prey and human tampering with the ecosystem both in terms of fish harvested and fish added either via hatcheries or changes in salmon management aimed at increasing production.

A variety of studies have theorized that human manipulation to create massive numbers of smallish, short-lived pink salmon – now the most abundant salmon in the Pacific – can lead to so many little salmon devouring so much prey important to other species of both fish and birds that they can trigger what are called “trophic cascades.”

Scientists from Alaska and Australia in 2018 implicated pinks in a trophic cascade that led to wrecks of short-tailed shearwaters in odd-numbered years from 2007 to 2013. Those migratory birds winter in Australia and summer along the coast of Western Alaska where they are heavily dependent on the same prey as pinks.

Old-year populations of pinks exploded in the new millennium as Alaska and to a lesser extent Russian hatcheries began flooding the sea with hatchery pinks. Alaska harvested a record 219 million pink salmon in 2013, according to the Alaska Department of Fish and Game.

That was more than double the 100-million, all-species harvest the state considered a benchmark for a good year in the 1980s.

Since the shearwater study in 2018, a variety of other studies have pointed to pinks as a major disruptor in the North Pacific ecosystem, but they are far from the only species involved in the ups and downs in the ecological fluctuations going on there..

As the Gulf of Alaska ecosystem report for 2023 concludes, a “reduced total zooplankton biomass could be explained by lower production, potentially connected to the late and reduced spring phytoplankton bloom, or by increased top-down grazing pressure. Predators of zooplankton increased in 2023, relative to 2022, driven by large returns of pink salmon, relatively large and increasing populations of Pacific Ocean perch and walleye pollock.

“Signs of a restricted prey base include a decline from above average to average zooplanktivorous seabird reproductive success, lower body condition (weight at length) of adult pollock, below average energy density of juvenile salmon, and juvenile pink salmon diet dominated by gelatinous prey, (a) less nutritious alternative to zooplankton.”

All of these indicators point to a probable, 2022 decline in pink salmon returns in line with the historically lower numbers of pinks in even-numbered years than in odd-numbered years, but why that is remains debated.

The prevailing theory is that odd-year pinks –  which are genetically distinct from even-year pinks and have for decades been more plentiful consume so much of the available food in the Pacific that odd-year pinks suffer from a lack of nutrition.  But there is far from a total agreement on that theory.

Managing chaos

Salmon happen to be the most-studied species in the Pacific, and yet comparatively little is known about their lives in the ocean where they spend most of their time.

As for those Pacific Ocean perch now on the upswing, NOAA confesses to knowing almost nothing.

‘There is much uncertainty about the life history of Pacific ocean perch, although generally more is known than for other rockfish species,” the agency says. “The species appears to be viviparous (the eggs develop internally and receive at least some nourishment from the mother), with internal fertilization and the release of live young. Insemination occurs in the fall, and sperm are retained within the female until fertilization takes place approximately two months later. The eggs hatch internally and parturition (release of larvae) occurs in April-May.

“Information on the early life of this species is very sparse, especially for the first year of life. Pacific Ocean perch larvae are thought to be pelagic and drift with the current. Oceanic conditions may sometimes cause advection to sub-optimal areas, resulting in high recruitment variability (variable survival to majority). However, larval studies of rockfish have been hindered by difficulties in species identification since many larval rockfish species share the same morphological (developmental) characteristics. Genetic techniques using allozymes and mitochondrial DNA are capable of identifying larvae and juveniles to species, but are expensive and time-consuming.”

More is known about species such as salmon, halibut and herring, which have been harvested and studied for their economic importance for more than a century. But even there much is unknown.

Chinook salmon, or kings as Alaskans usually call them, have been declining in number in the Gulf of Alaska for decades, according to Canadian researchers, and have crashed in the Bering Sea.

No one really knows why.

A 2022 NOAA assessment of “What We Know” as to the situation in the Bering Sea is actually an assessment of what scientists “believe” could be happening. It is couched with the ” pretty good relationship(s)” researchers see between numbers of young and mature salmon, the things scientists “suspect,” the observation of environmental conditions “that may have something to do with this,” and the “potential factor(s)” influencing changes in salmon numbers.”

Presenting the best available evidence as to what is happening as a definitive known comes across to some as little more than propagandizing which, in turn, helps fuel an alternative belief that declines of both chum and Chinook salmon in the Kuskokim and Yukon rivers, the two biggest North American rivers draining into the Bering Sea, are really the result of bycatch in the $1 billion pollock troll fishery.

There is no solid evidence to support this alternative, but it has been backed by Rep. Mary Peltola, Alaska Native tribal leaders from Western Alaska and some halibut and salmon fishermen.

“Alaska’s Fisheries Are Collapsing. This Congresswoman Is Taking on the Industry She Says Is to Blame,” Politico headlined in March.

The story below highlighted the “inequality” between restrictions on fishermen in crab, halibut and salmon fisheries in decline and the profitable pollock fishery wherein “trawlers, some as long as a football field, which drag vast nets along the sea bottom, also scoop up millions of pounds of species they don’t actually want, and they throw most of it overboard no matter how valuable it might otherwise be.”

The story went on to challenge the official position of NOAA scientists, which is that – at least when it comes to salmon – bycatch represents “less than 3 percent” of the removal of Yukon River Chinook and even less of Yukon River chum.

Genetic studies of chum have shown “most of the chum salmon caught as bycatch in commercial groundfish trawl fisheries in the eastern Bering Sea are either hatchery fish from Asia or fish from the Eastern Gulf of Alaska/Pacific Northwest, the southern stocks including Southeast Alaska, British Columbia and the lower 48.  Considerably fewer chum salmon are from Western Alaska,” according to NOAA.

The data would indicate that if anyone should have a complaint about this by-catch, it is the Japanese, who’ve invested heavily in chum salmon hatcheries; the Russians and, to a lesser extent, commercial fishermen in Alaska’s Panhandle who have also made significant investments in chum hatcheries.

” …In 2021, of the 545,883 total chum salmon taken as bycatch, 67.6 percent of these fish were from Asia. Around 9.4 percent (51,510 fish) were from Western Alaska, which includes the Yukon, Kuskokwim, and Nushagak rivers and areas in Norton Sound and north. Because of natural mortality at sea, not all of those western Alaska salmon would have returned to their natal rivers to spawn or been available to in river fisheries.”

Do the math

If all of those fish made it back to the Yukon, Kuskokwim and Nushagak rivers – the biggest chum producers in the region – the trawl harvest would have comprised about 13 percent of the returns to those rivers in 2021, a dismal year for chum salmon throughout the region.

But there is a big problem in looking at the issue this simplistically.

A report to the North Pacific Fisheries Management Council, the federal group responsible for managing at-sea fishery harvests beyond three miles from the Alaska coast, reported that “an estimated 690,000 Western Alaska chum salmon were harvested in the June Area M fishery” in 2021.

What is commonly called the Area M fishery is what the state of Alaska officially calls its “South Alaska Peninsula Management Area.” A salmon intercept fishery targeting adult salmon trying to slip through the east end of the Aleutian Island chain when returning from the Gulf of Alaska to Bristol Bay and the Bering Sea has operated there since the 1900s.

The fishery has become increasingly controversial in recent years. In 2021, the worst year on record for chum returns to the Kuskokwim, the Area M catch of mature chums bound for Western Alaska spawning grounds was more than 13 times larger than the trawl bycatch of salmon of all ages.

If the Area M removals are added to the returns to the Yukon, Kukskowim and Yukon to get a better idea of actual chum abundance, the trawl bycatch of chum for 2021 falls to less than 5 percent of the total return of Western Alaska chum in that year.

Whether that removal is justified to support a catch of 1.3 million metric tonnes of pollock in in the same year can be debated, but a harvest of this size falls far short of Politico’s suggestion that it was to blame for the collapse of Western Alaska chum fisheries in 2021 when, for unknown reasons, large numbers of four- and five-year-old chum failed to make it back to their spawning streams as expected

Politico also claims “evidence is growing from government agencies including the National Oceanic and Atmospheric Administration, conservation groups and fisheries scientists that the trawl industry is causing greater damage to marine habitat than previously assumed and that the removal of vast quantities of pollock, an important source of food for other species such as fur seals and Steller sea lions, is causing disruptions to the larger ecosystem,” but cites no studies with any data to back up that claim.

It does, however, quote from and link to a report by NOAA scientists saying the nets used for mid-water trawls for pollock do too often hit the bottom of the Bering Sea, which could explain part of the decline in crab stocks there.

According to the report, “how often pelagic trawl gear is contacting the seafloor in the Bering Sea – can be, and has been, studied empirically” – and all indications are it regularly contacts the seabed, but the scientists added that they wanted “to make clear that the direct and indirect impacts of pelagic trawling, or trawl gear in general, is not presumed to be the sole driver of the decline in the Bristol Bay red king crab stock that has been ongoing since around 2007 and has recently come to a head with the closure of the 2021/22 directed fishery.

“Trawling that contacts the seafloor is assuredly one of the factors that challenge the (crab) stock; other factors to account for include directed crab fishing, the effect of other groundfish gear types, and (crab) stock dynamics as influenced by the changing ecosystem.”

The Politico story left out these qualifiers as to the damage done by trawls hitting the bottom, and they do do some damayage. The NOAA report offered some suggestions to the Council on modifications to trawl gear or area fishing closures that could make the trawl fishery fish cleaner along with options for replacing trawls with other sorts of gear that fish cleaner.

A big, near-invisible business

Such changes would, however, run into strong opposition from the Seattle-based companies with big investments in trawlers, and as the Politico story accurately pointed out, “conflicts of interest are built into federal fisheries management and have become entrenched. Industry representatives or commercial operators with ties to the trawl fleet frequently serve on the North Pacific Fishery Management Council, the regional NOAA body which regulates the industry, and vote on policy that affects their sector.”

One former member of the self-described Council “family” that doles out the rights to harvest about $2 billion worth of fish every year once described the whole Council system established by the Magnuson-Stevens Fisheries Conservation and Management Act as “legalized corruption.”

Despite this, the biologists and other analysts involved in advising the Council on the management of North Pacific fisheries have done an admirable job of keeping the train of harvest on the tracks of sustainability

Low numbers have forced restrictions in harvest in some fisheries in all years and closures in other fisheries other years, as is the case with a variety of crab and salmon fisheries now, but the fish stocks themselves have remained in a generally health state.

Unlike the problematic situation along the West Coast of the lower 48 states, no Alaska stocks are at this time considered “threatened” let alone “endangered” in the ocean that continues to support the nation’s largest commercial fishery harvests.

NOAA’s most recent report on “Fisheries of the United States” records the waters in and off Alaska account for 60 percent of the country’s wild seafood catch with the Alaska port of Dutch Harbor the most important in the nation. 

Landings in Dutch were more than twice those in any Lower 48 port in 2020 with “other Aleutian Island” ports ranked second for landings and Kodiak third in the nation, according to the report.

Dutch did, however, drop to third for value as NOAA noted “Alaska pollock hit a new five-year low (price) as did chum salmon, sockeye salmon, and herring. The reduction for some of these species is greater than the overall landings for some states.”

The Alaska salmon industry has been hard hit by competition from salmon farmers who produce can produce fresh fish year-round. Given that Americans, on average, annually consume about four times as much fresh or frozen seafood as canned seafood, the farmers have a significant marking advantage over producers who can a lot of their fish.

That is especially so when one takes into consideration the fact that Alaska canned salmon competes with canned tuna in the marketplace and the former, according to the NOAA data, outsells the latter by more than six to one.

Salmon canneries were once a mainstay of the Alaska fishing industry, but they have steadily faded away over the years with increasing numbers of salmon being processed into more valuable, frozen filets. But still most processors are struggling to maintain the profits that keep them in business.

The Alaska commercial fishing industry isn’t going to go away. There will always be money to be made given that wild salmon cost nothing to grow, but the future for those involved in the commercial fisheries looks to be almost as chaotic as the North Pacific ecosystem itself.