Ecosystem management

A young salmon with a grim future/Katrina Mueller, NOAA

Are disappearing Yukon River king salmon collateral damage?

Conservation biologists have been talking for decades now about something called “ecosystem management,” but it is hardly ever practiced.

Politics fueled by money, good intentions of varying flavors or who knows what else invariably get in the way. Thirty years ago, good intentions basically brought an end to wolf control in the 49th state. Now good intentions are fueling a limited war on wolves.

In the first case, the good intentions were aimed at “saving” a much-maligned wild predator. In the second, they are aimed at feeding Alaskans with the meat of moose and caribou.

Turning now to the Bering Sea – a far more complicated ecosystem than even the most complicated of Alaska terrestrial ecosystems involving wolves, grizzly and black bears as predators, and moose and caribou as prey – both good intentions and economics are in play.

The finger of blame for possible human tampering in the decline of Yukon kings has so far been pointed at by-catch in trawl fisheries and global warming.

Alaska scientists Kathrine Howard and Vanessa von Biela theorized that the latter could be a major issue confronting the largest of the Pacific salmon and the Alaska state fish.

The big heat

“Over the past two decades, parents that experienced warmer water temperatures and lower discharge in the mainstem Yukon River produced fewer juveniles per spawning adult,” they wrote in a paper published in peer-reviewed Global Change Biology in January. “We propose the adult spawner life stage as a critical period regulating population dynamics.”

The theory is basically that adult salmon weakened by battling their way upriver through waters sometimes warm enough to be nearly deadly to the fish fail to spawn or weaken their eggs and sperm.

As a result, there are fewer eggs, fewer of the eggs hatch, and fewer of the king fry survive the long journey down the river to the Bering Sea. It’s a plausible theory, but there is no good background data on Yukon king egg or fry survival to buttress it, and salmon fry often have very high mortality rates.

Egg-to-fry survival rates, according to the National Oceanic and Atmospheric Administration, have been estimated from a low of 9 percent to a high of 90 percent.

The survival rates for Chinook going from the fry to smolt stage at which they enter the ocean are less well documented, and much of the research has been done has focused on Lower 48 river systems highly modified by agriculture and dams. It’s generally agreed that dams take a turbine-size bite out of the survival of young salmon trying to migrate to sea.

A Canadian study conducted in the 1990s did put the fry-to-smolt survival rate at 3 to 34 percent but conceded the calculation was pretty unreliable given the dearth of data.

Still, considering that Yukon Chinook live near the northern limit of the species’ range, let’s presume, just for the sake of argument, that in a historically normal scenario, 30 percent of the eggs hatched to become fry and 15 percent of the fy survived the journey to the ocean.

Under this scenario, if you start with 100 eggs, 30 of those eggs live to become fry, and between four and five of those fry make it to the ocean.

Death everywhere

Life is hard if you’re a salmon because salmon are not just food for homo sapiens. Salmon are food for a wide variety of other animals from fish to birds to marine mammals, and most of these animals prey on the young as is the norm in nature.

Among the young of the so-called “prey” species, more become food than become adults. And whatever the rate of egg-to-river-exit survival for Yukon Chinook, it’s probably safe to say the vast majority never make it to the ocean where there are a whole lot more animals waiting to kill them.

Alaska Rep. Mary Peltola, D-Alaska, is now on the warpath about the number of these fish that die as bycatch in Bering Sea trawl fisheries. Politico praised her in April as a woman who “won her election by campaigning on a platform to save the state’s prized fisheries. A powerful fishing lobby is standing in her way.”

“The fleet of nearly 250 trawl boats that catch groundfish (species such as pollock and yellowfin sole that congregate on or near the ocean floor), have recorded banner seasons – permitted to bring in between 3 and 4 billion pounds of fish annually for worldwide distribution,” reported the story below. “What makes this inequity especially jarring for the captains of halibut, crab and salmon boats is that the 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 fishery that is the focus of bycatch charges vis-a-vis Yukon kings is the pollock fishery, which – according to Marine Stewardship Council, an international non-profit that tracks and certifies sustainable fisheries  – is a “midwater trawl  fishery,” not a bottom dragger, with “proportions of bycatch (that) are very low, below 1 percent.”

NOAA echoes that assessment by saying that the nets might sometimes make contact with the bottom, but “have minimal impact on habitat” in “one of the cleanest (fisheries) in terms of incidental catch of other species.”

Nonetheless, among the general public, by-catch of Chinook salmon in the pollock fishery is a widely popular explanation for why returns of kings to both the Yukon and the nearby Kuskowim River have tanked. This is especially so in Peltola’s hometown of Bethel.

Never mind that most of the scientists who’ve seriously looked at the issue aren’t buying the explanation.

As Howard and von Biela observed in their paper, “Chinook salmon production patterns are likely unrelated to events that occur later in the marine life such as: bycatch in high seas commercial fisheries, directed Chinook salmon fisheries in marine or estuarine waters, or the predation of marine mammals on larger and older salmon.”

“Consequently, the life history periods of interest for understanding Yukon River Chinook salmon population dynamics include the spawning adults, egg, fry, and smolt/marine juvenile life stages.”

Maximum sustained mistakes

The latter could be highly important because of the decades-long, MSY management of pollock, along with Bristol Bay sockeye salmon and Russian pink salmon. MSY, or “maximum sustained yield” as even most of those only remotely familiar with commercial fisheries will recognize the acronym, has long been the holy grail of fisheries management.

NOAA is especially proud of how its MSY management of Bering Sea pollock has maintained an annual harvest of around 1 million metric tonnes (2.2 billion pounds) per year since the mid-1970s.

Pollock catch/NOAA


“Management of fisheries off Alaska is, by all accounts, a success story of biological and economic sustainability,” Chris Oliver, then the executive director of the North Pacific Fisheries Management Council told Congress in 2005.  The NPFMC, or the council “family” as it sometimes refers to itself, is a government-appointed citizen committee that determines fishing allocations and sets quotas for harvests in the federal Fishery Conservation Zone (FCZ) from three to 200 miles off the U.S. coast.

Those regulations are then reviewed and codified by NOAA, an agency within the Commerce Department. The reviews are usually just a rubber stamp.

In his speech to Congress, Oliver referred to ecosystem-based management, ecosystem considerations, ecosystem functions, ecosystem forums, the overall ecosystem, ecosystem plans, ecosystem-related research, ecosystem-oriented management, and the ecosystem, 42 times but NPFMC fishery management has a lot more to do with money than with the ecosystem.

“These fisheries are worth nearly $1 billion ex-vessel annually (amount paid to fishermen at delivery, prior to value-added processing),” Oliver said. “The groundfish fisheries account for a majority of the overall value, but the halibut, salmon, and shellfish (crab) fisheries also contribute substantially.

“Additionally the Council’s community development quota (CDQ) program allocates from 7.5 percent to 10 percent of all groundfish and crab quotas to six CDQ groups consisting of 66 western Alaska coastal communities. Through partnerships with other industry groups, and through direct involvement in fisheries and development of fisheries-related infrastructures, this program allows these remote coastal communities to continue and enhance their participation in Alaska fisheries.”

Needless to say, there are a lot of big-money interests involved in promoting MSY management of Bering Sea pollock. So what never gets considered is that there’s a catch with MSY management of anything in a natural ecosystem.

A big, yet simple catch: You can’t have maximum everything.

Ecosystems have carrying capacities that create a zero-sum game. In order to maintain one species at a maximum, you have to accept that others will operate at a sub-maximum.

Historic example

To go back to that most simplified of predator and prey relationships involving moose and wolves, you can have a maximum number of moose, and you can have a maximum number of wolves, but you can’t have maximum numbers of moose and wolves.

The National Park Service has been closely monitoring wolf and moose numbers in Isle Royale National Park since 1980. Over the course of the last 43 years, wolf numbers have ranged from 50 to two, and the moose numbers from nearly 2,500 to nearly 500.

Over this time, the periods with maximum numbers of moose and maximum numbers of wolves have never coincided.

The Bering Sea is a far more complex ecosystem than Isle Royale, but that doesn’t exempt it from the fundamental rules of nature. And the Bering Sea has been chockablock full of pollock for decades now and increasingly of late with sockeye salmon from Bristol Bay and pink salmon from Russia.

All of these fish, depending on size, eat each other. All of these fish have overlapping diets, meaning they compete, to greater or lesser degrees, for the same prey. One of these fish, the pink salmon, is believed to have a competitive advantage in warmer waters. 

All of them, for all science, knows at this point, might have a competitive advantage over Chinook in the Bering Sea. If that were to prove to be the case, the problem would not be that trawlers have too many Chinook in their bycatch; it would be that the trawl fishery is catching too few pollock.

It would mean that way to help Yukon and Kuskokwim king salmon would be to decrease the pollock biomass, forcing the annual harvest to something below 1 million metric tonnes per year, and then holding it there, stabilizing the Bristol Bay sockeye return at something near historic levels rather than the record levels of today, and trying to get the Russians to manage their pinks for something less than maximum numbers in the interest of improving the niche for Alaska Chinook.

But even if a mountain of scientific evidence were to accumulate documenting this as the problem, such changes are pretty much unthinkable because pollock and salmon support the far and away the most valuable fisheries in the Bering Sea. And thus they are likely to go on being managed at MSY no matter what their relationship with Yukon kings.

And the kings, well, they are unlikely to disappear. Salmon are an incredibly resilient species. But the Yukon could well be looking at a future with a lot fewer fish.









13 replies »

  1. So the question is does 1,400 kings heading to the Yukon that wouldn’t get scoped up by the trawl fleet in Area M contribute to the sustainability of Yukon Chinook or not?

    The words in Article 8, Section 4 Sustained Yield of the Alaska State Constitution would say the 1,400 kings are indeed need in the Yukon drainage.

  2. But wait, what if the latest NPFMC report said that Bering Sea “mid-water” trawls are *actually* on bottom 40 to 100% of the time(depending on what vessel is towing them and what fishing season they’re in)..?

    That would be bad and they would put a stop to it immediately, right…?

  3. “… to help Yukon and Kuskokwim king salmon would be to decrease the pollock biomass…”. Unless there is a way to harvest more pollock without by catch, the collateral damage would be too high.

  4. Again I say process every thing you catch, NO by catch, then the truth will come out

  5. My brother has lived in Eagle almost 50 years. He told me that when the tourist paddlewheel boat traveled between Eagle and Dawson City, the “wake” would wash salmon fry onto the shore where they died. He said Canada complained about it, but he isn’t sure if it was economics that halted the trips or pressure from the Canadian government.

  6. Death by 1,000 cuts perhaps?

    History has proven Most Scientists of this era or maybe any era tend to be inaccurate and usually proven wrong later . Thats the trend . The minority is usually correct the majority is usually inaccurate.

    Thus regarding “knowledge of kings” every scientist analysis needs carefully reexamined and proofed before we attempt to build a hypothesis.

    we need to see exact fry production numbers, escape numbers, water temp numbers, accurate water temperature survival correlation numbers for this water shed. Historical freshwater temp numbers. Ect . We need the exact variables for freshwater survival.
    Anything less = an unknown
    Could temperature be one of the important variables? Probably. The primary variable? Unlikely and shouldn’t be assumed until all other controllable variables are eliminated.
    ( temp is important in hatcheries to an extreme)
    I understand that 100%

    It’s foolish to focus first on the one variable thats near impossible to change.

    over harvest has historically been a reason behind many species decline.
    That could be adjusted or changed with agreements .

    Historically Most species can adapt to small changes in the environment. ( not including catastrophic) blaming global warming when its a matter of a few degrees average smacks of a fad especially when we don’t know the specifics for this watershed.
    Our temperatures have fluctuated for eons.
    Odds are kings evolved to adapt to a slight change.
    I say we must be wary of choosing the easiest answer which could be a cop out to absolve ourselves.

    are water temps causing a drop in all king salmon survival? How is Bristol bay ? Why hasn’t Bristol bay kings crashed? This is important to know.

    Is it water temperature on the kenai or are we blaming nets ?
    Blaming sport fishers?
    What’s causing a fair decline in copper river kings ?

    We must ask – what has changed significantly?
    Trawling? Commercial fishing of all types? Commercial fishing is a huge variable when you consider it’s been directly connected to many fish species population collapse. Its also become increasingly efficient and technologically advanced.
    What else?

    Very Important question-Is commercial fishing effecting the ocean kings food supply?
    Is commercial fishing causing orcas sharks ect to target kings ? Predators are good at recognizing patterns and adapting to eat whatever food source is available.

    We dont have in river pollution to huge degrees on the yukon. What do we have ?
    Is it 1,000 cuts ? What needs done to rebuild the stocks?

    Can you blame the native population for suspecting over fishing in the ocean when there is insufficient data to give a solid answer? Yet overfishing is the most easily recognizable and understood variable?
    In river catch controls hasn’t helped much.
    Its time to look at other variables in an extreme fashion.
    Many of Alaskas people subsisted for 10,000 years with salmon partially kings as a significant part of the diet. Often the second protein to breast milk. These people are attached to this resource in an instinctive sense.
    Salmon often meant survival.
    Now salmon means survival in a more abstract sense but for their inner being it’s nearly as important.
    If they were a warlike people they would be boarding trawlers.

    Myself I wouldn’t blame them. Perhaps I would join.

    One user displacing another has been history but that doesn’t make it any more right than a man beating a woman in the woman’s division of sport .
    ( at least in a civilized society)

    So lets all back some significant studies. Not jump to conclusions and lets do consider placing the kings on the endangered list before the are gone .

    In my book its not acceptable to accept their will just be a lot less kings in the future.
    That would be a weak decision.
    There has already been to few for to long .

    This is not partisan issue. Its an issue regarding the cultural and financial survival of our state.
    Lets band together to protect alaskas future.
    The king’s future.

    • I don’t know who Dread Pirate is, but they are well worth listening to. Too much fisheries science is being lazily based on correlations which have not undergone rigorous and skeptical examination. Basing policy on correlation risks real disasters if later the correlations do not end up being the casue. This is especially true if a species is on the edge and we continue to craft policy for the politically powerful and ignore the real cause, sending a species into the extinction bin.

      Most good scientists know that these mathematical correlations generated coiously since the advent of latops and Microsoft Excel spreadsheet. We have a generation of fisheires scientists who would rather generate mathematical correlations, then go into the field and get rained on.

      Let me give you one very strong mathematical correlation that has nothing to do with causation. The number of ice cream cones sold on Catalina Island has a strong mathematical correlation to squid harvests. So do squid harvests cause ice cream, Nope but the laptop warriors might suggest the theory, but in reality the casue of this phenomenon is that when the wind doesn’t blow you catch more squid and sell more ice cream.

      Solving fisheries problems like these requires a clear eyed and brutally honest review of all potential impacts and then ensuring that all users producing these impacts contribute genuine sacrifices together with all users to ensure the species recover.

      In my opinion during my lifetime (50 years fishing) the pattern has been that the politically powerful that have the largest impacts and try to force the politically unpowerful to eat most of the conservation sacrifices, which destroys trust and cooperation.

      Well stated Mr. Pirate

    • Mr. Medred, I never mentioned the Yukon River.

      I know of one trawler that captured approximately 50,000 lbs. of Chinook salmon in a single tow of their trawl. This tow is recorded nowhere.

      Obviously this fishermean moved and felt bad about what was truly and accident, but folks need to understand that there have been incentives to under-count Chinook and Chum bycatch from the very beginning of the American trawl indsutry since the very beginning. There are a lot of shenanigans that happen at sea. Even the 100% observor policy advertised is misleading. 100% means there is a single observor onboard, but they only work 8 hours a day, while the harvesting takes place 24 hours a day.

      Observors onboard boats at sea are trapped, and treated like snitches in prison.

      Why this is important to the successful recovery of Chinook salmon is not the total number. You can do the math all yo want and swear that the trawlers could not be the core problem. Oddly, I agree, but you miss the point, the recovery to be successful is not a math problem. It is a people problem.

      In order to craft a successful plan that actually delivers results and saving the Chinook salmon, one has to be brutally honest with all the party’s that have impacts.

      As soon as one party is allowed to slither away from their true impacts, then the other partys’ slither away from their impacts.

      Absolute truth is the key. The trawl industry is not being truthful.

      I believe that we need to insitute a pollicy of trust, but verify on all partys’. Nobody, no matter how powerful get a pass.

      Since you brought up the Yukon, let me give you a concrete example. A decade ago there was an illegal and rampant Chinook fishery around Fairbanks on the Yukon River. One of the excuses given by the participants was the unlimited and rampant trawl catches of Chinooks and Chum salmon by the Bering Sea pollock fishery.

      They were not entirely wrong. When one party gets an unlimited bycatch quota and frankly, under-reports their bycatch, the upriver folks have a legitimate point. The whole conservation of both chums and Chinooks now falls on the villages along the Yukon. (This is probably a violation of the 14th Amendment to the US Consitituion)

      One one party gets, they all want a pass.

      The absolute truth is critical to the process of shared sacrifice.

      Put your spreadsheet away.

      • Doug: I’d say we’re wholly in agreement on trust but verify, and I’m glad to see you mentioning illegal harvest. I would expect that is still going on in places along the river. But that said, given the numbers here, there has to be more than harvest in play.

  7. Are the 40 years of trawl bycatch records of Chinook accurate?


    Nobody wants to validate these often self-reported bycatch numbers. (the early years)

    Interviewing retired trawl deckhands will validate these numbers. (or invalidate them)

    • Well, since the observer program is only 33 years old, I think we can safely say the first seven of those years were surely and decidedly inaccurate. And I would expect, just given the nature of how these things work, that early program was less accurate than the program of today.

      Still, I’m skeptical the numbers today are perfect, but I’m pretty comfortable with the numbers coming from the genetic testing because those fish are actually sent to a lab to be tested, and there really is no way for someone on a boat to tell a Middle/Upper Yukon Chinook from another Chinook.

      But the numbers just don’t work no matter how hard I try to make the case for bycatch as the problem.

      The genetic data is saying 2.3 percent of the bycatch is M/U Yukon kings. But let’s say that’s off by 100 percent. So then the latest number is 4.6 percent of 15,000 or about 690 fish.

      Now, for the sake of argument, let’s also say the by-catch number is off by 100 percent. So instead of 15,000 Chinook, we’re talking 30,000 Chinook.

      30,000 x 4.6% = 1,380.

      This still doesn’t begin to account for the number of Chinook missing at the Canadian border this year, let alone those missing in the middle Yukon. The minimum target at the border is 42,500. The goal range at the border is 42,500 to 55,000. The 1,380 would be but 11 percent of the variance in the goal.

      The Canadians put the border count at 12,025 this year. That’s so far from the goal that even if the trawl catch of those fish had been 1,380, it would be so small as to be approaching the 5 to 10 percent margin of error of a sonar counter.

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