National Geographic Daily News
Pink salmon in Alaska.

Pink salmon (shown above spawning in Alaska) have increased since the 1970s, with an estimated 640 million returning to their breeding rivers in Asia and North America in 2009 alone.

Photograph by Paul Souders, Corbis

James Owen

for National Geographic

Published March 31, 2014

Too many fish in the sea? Surging pink salmon stocks in the Pacific Ocean pose a risk to other wildlife, suggests a seabird study released on Monday that points to climate change as a culprit. (Related video: "Alaskan Salmon Adventure.")

Along with other salmon, pink salmon (Oncorhynchus gorbuscha) numbers have grown since the 1970s, with an estimated 640 million returning to their breeding rivers in Asia and North America in 2009 alone. (Read "The Long Journey of the Pacific Salmon" in National Geographic magazine.)

Tied to rising ocean temperatures in the Bering Sea and North Pacific that spurred the growth of the prey of salmon and seabirds alike, the "much larger than previously known" impact of pink salmon is reported in a new Proceedings of the National Academy of Sciences report.

It's "an uncommon case of too many fish in the sea," says the report. The study, led by Alan Springer of the University of Alaska Fairbanks, found that salmon eating the food of seabirds appears to be cutting the birds' numbers.

"Very little is known about how open ocean ecosystems work, and the apparent effect on them by salmon, wild and hatchery produced, really must be considered," Springer said by email.

The finding points to unanticipated side effects on wildlife from climate change, with unexpected winners and losers. The just-released Intergovernmental Panel on Climate Change report (unrelated to the new salmon study) warns, for example, of warming oceans threatening Atlantic cod and tuna species. (Related: "New Climate Change Report Warns of Dire Consequences.")

Seabird Colonies

To investigate potential food competition between pink salmon and other marine life, the team focused on seabird colonies in the Bering Sea and Aleutian Islands. Monitored by scientists since 1984, these colonies changed as the number of pink salmon increased.

Specifically, the study team tied the breeding fortunes of seabirds to the two-year life cycle of pink salmon. Each year, the salmon naturally alternate between high and low levels of abundance in the sea.

In the salmon-rich years, the team found, the breeding success of birds such as kittiwakes and puffins was significantly less than in the alternate years. Some species laid fewer eggs, up to half as many as they did previously; the eggs also hatched much later, and fewer of the young survived.

The affected seabirds are species that, like pink salmon, have an omnivorous diet, with prey ranging from zooplankton to squid and Atka mackerel.

Evidence that pink salmon are "a major influence" on these seabirds is "compelling," the team concludes.

"Phenomenal Increase"

The findings come as no surprise to Pacific salmon scientist Greg Ruggerone of Natural Resources Consultants, a marine fisheries consultancy based in Seattle, Washington.

Ruggerone, who wasn't involved in the study, has previously raised the issue of the booming pink's ravages, finding that the species cut the Alaskan populations of another Pacific salmon, the sockeye, through prey competition.

Explaining how rising sea temperatures have fueled the pink's "phenomenal increase" since the 1970s is a complex issue, Ruggerone said. But their springtime departure from the river to the sea as tiny juveniles could be key.

"Early marine survival is critical to overall abundance," he said, and higher sea temperatures in spring would mean more prey are available and lead to a higher metabolic rate in the salmon, allowing them to eat more and grow faster.

In their second year, the new study notes, pinks consume enough food in a four-month period—one which overlaps with the seabirds' breeding season—to increase their body mass by 500 percent.

This drain on the North Pacific's food resources could well have direct and indirect effects on other marine animals, such as recovering populations of great whales, the authors write.

Rethinking the Ocean

Salmon-biased conservation measures, such as commercial fish catch limits and large releases of hatchery-reared salmon, may have to be rethought in order to conserve other marine creatures, the study argues.

While recognizing the importance of Pacific salmon both commercially and as a food, the authors caution against "using the oceans as unattended feedlots." (Related: "Sea Lice From Fish Farms May Wipe Out Wild Salmon.")

This idea of scaling back on pink salmon doesn't unduly faze Rich Lincoln, director of State of the Salmon in Portland, Oregon, a program set up by the Wild Salmon Center to guide the conservation and sustainable management of Pacific salmon.

"The idea of at least 'freezing the footprint' of existing hatchery programs has been increasingly heard as a logical precautionary response to some of the uncertainty surrounding the potential impacts that pink salmon abundance may have on other species," Lincoln said by email.

Ruggerone's own research puts the hatchery-bred proportion of the total pink salmon stock at about 13 percent, although the hatchery-to-wild fish ratio is significantly higher for regions such as Alaska. (Related: "Salmon Farming Gets Leaner and Greener.")

As for increasing the commercial catch of pink salmon to deliberately reduce numbers, "this would be a novel idea," Lincoln said.

"I've only really heard this kind of discussion to date surrounding introduced species that are having a negative ecosystem effect," he added. "It might be logical first to address the magnitude of artificial inputs of hatchery fish."

Even so, "it's an intellectually interesting idea," Lincoln conceded.

Eat wild salmon to save the ocean? A seafood marketing dream may be the wave of the future.

27 comments
William Manatee
William Manatee

As a man who has taken part in the capture and processing of literally millions of salmon, both sockeye and pinks, I grow weary of some of the tangential rants that we are hearing these days.  Alaskan fisheries were overrun with abosolutely enormous runs of pinks last year, both in Prince George sound and in SE Alaska.  Minimum wage processors in Petersburg took home up to $10,000 for two months work due to the abosolutly stunning amounts of overtime. 


Now, I don't see anyone talking about the Haida Project ... while, arguably, what to some is a bizarre act of disobedience, and to others a foolish waste of money and to yet others, including some pink salmon processors who got fabulously rich in 2013 ... it was a masterstroke of windfall enormity.


What I am talking about is the diliberate placement of what some claim to be Ferrous sulphate, while others say it was a "finely divided reddish dirt."   Some individuals say that 100 tons were dispersed, others say that the total amount was even more.  Still other well-meaning souls assert that the amount of material distributed in the Haida geo-engineering experiment was negligable compared to the millions of tons of mineral-enriched volcanic dust that was spewed over the entirety of the Gulf of Alaska in 2008 during the violent and shocking eruption of Kasatochi Island.


Whatever is causing this, the pink salmon party is just beginning.  My hat's off to those individuals who find it to not be very tasty.



james nightstar
james nightstar

Yeah i agree sometimes at night i do think about this

S. Gonzalez-del-Pozo
S. Gonzalez-del-Pozo

Perhaps the overzealous killing of Sharks and Dolphins to satisfy "fin soup and dolphin meat" eaters has something to do with it, after all, they are two of the major predatory oceanic species that regularly eat Salmons.

Sydney Tudela
Sydney Tudela

I so totally doubt that there is ""TOO &/or  THERE'S MANY FISH IN THE SEA""..Even the sense of the "SAYING" does not even seem to be right to or coexist to say no more....


I love Salmon, I'm from the Pacific Islands - I/WE LOVE SASHIMI / SUSHI & we could do lots with the Salmon..Even though it's sold so expensive in the Islands we still buy it.....to to oppose to you saying that there's so much of it........Crazy!!!!!!!!!!!! 


Louis Hooffstetter
Louis Hooffstetter

This is by far the stupidest article I have ever read. For decades, 'scientists' have been warning us of over fishing, ocean acidification, and species extinction. Now a healthy population of fish that occupy the lower portion of a food chain that supplies an entire web of inter-related eco systems is twisted to be a catastrophe.


Global warming is causing too many Pink salmon and too many Red King crabs (Google it)? This is just another unsubstantiated climate scare story.


Rejoice and be happy that the food chain is healthy and sustainable. These 'scientists' are witch doctors!

Jed Alexander
Jed Alexander

And which seabird is this terminally targeting, kittiwakes, certainly seen plenty of them out on the ocean...this sounds like some bored theory someone was assigned and holds no water....it'd be detrimental if we ate puffins and kittiwakes though huhhhh?? i think the population of most seabirds are high enough especially in alaska.......why doesnt Nat Geo look at the effects of all the mining companies that are more detrimental to salmon stock and other wildlife or as far as this article is concerned maybe we have too many cows producing methane and causing global warming and the depletion of deer ticks in kentucky blah blah...sounds like the blind leading the blind. . as a commercial fisherman myself we had a record year in Prince William Sound for pink salmon in 2013... Alaska alone harvested i think around 218million Pink salmon commercially..is that enough???lol and i believe pink salmon have more of a 3yr run rate not a 2yr....conveniently the best fishing years have been odd numbered years....really disappointed with this article....


Sam H.
Sam H.

Yeah right I don't believe this! considering it goes against everything our scientist have been saying for years!!!

Richard Adams
Richard Adams

Sic Japan on them. They'll have the population reduced by 95% in a single year. Look at what they're doing to the rest of the marine life on the planet.

David Ingraham
David Ingraham

Back in the 1970's this magazine had allot to say about how the world was going to run out of fossil fuel in as short at time as 25 years. The voice of the reference that talks of various threats to the survival of man and resources necessary for the survival of man have been highly exaggerated by the supposed scientists of this magazine. Any proposed threat of declarations of possible threats are better provided to the public with evidence of proof. Other wise this magazine is only telling lies. Now we have to many salmon competing for food in the ocean depriving other species of said food. 10 years ago there was considered a shortage of salmon. This was to justify the removal of dams on the west coast rivers. I can assume there is no longer a shortage of salmon. All of this is supposedly caused by the unproven event of global warming. the lies just keep coming. I do not read or buy National Geographic, due to the false prospective presented on its pages.     

Richard G.
Richard G.

Remember that the passenger pigeon numbered in the billions....and then were extinct in a hundred years thanks to our "help".

Aldo Leupold
Aldo Leupold

Sell an "increased bag limit" tag to recreational fisherman that allows them to keep more than the legal limit, you will make millions upon millions selling the tags (and collecting taxes on hotel rooms, fishing gear, tourism) and be able to knock down the population in a responsible, controllable way. Sounds like time to plan a trip to Washington..

Carter Fox Jr.
Carter Fox Jr.

First y'all say that there is Nuclear radiation throughout the pacific, and now you want to put salmon on the menu. Yesterday I read the Dr.'s are stopping blood pressure medications for senior's in their 60's. Then we have Congress mad because folks will finally get health care.  Seems to me, like someone in the scientific community, is making it awful easy to write off a few million unsuspecting folks. Cancer must not be making it's quota this year. Climate change is gonna do what it do, because this is why they call it "Climate".

Bill Mathisen
Bill Mathisen

Not to worry...These "Surging Salmon Stocks" will end up as "Incidental By-Catch"

Bull Durham
Bull Durham

So the oceans are dying, but we have too many edible salmon and need to reduce them by not catching them?


It's Alice in Wonderland. Zombie Climate from the UN. Salmon overbreeding, getting obese, and we have to save sea-going birds.


Save us from these "expert environmentalists"!

Water Colour
Water Colour

@Louis Hooffstetter  


The limits of habitat in the Pacific Ocean for salmon growth and production have also been detected by scientists for decades. Most of this boost in salmon production is being generated by hatcheries, which have been most successful at pumping out the least "valuable" salmon species (pinks, chum) by the millions for decades, especially in Asia (Russia, Japan) as i understand it. 


The end result is heavy competition for increasingly scarce food resources, especially in the "pink" years (every other year). Basically shrinking the available habitat when combined with ocean changes. 


End result is slower-growing (and therefore smaller sized) fish of a lower quality.  There might be millions of them, but the glut of low-value fish just drives the price/kg down to the level where it is pointless for commercial fishermen to even go out to catch them. 


Not sure why hatcheries aren't reigned in -- to focus their efforts solely on high-value salmon (sockeye, chinook, coho) -- but that would take a lot more international cooperation to make it happen.


That's my 2 cents, as they say.

Charlotte Lenox
Charlotte Lenox

@David Ingraham Thought I'd point out one tidbit here, since I grew up in Alaska and have sportfished salmon, and I have done some research on salmon. This article is talking about the overabundance of one species of salmon, the pinks (Oncorhynchus gorbuscha). Some of the recent dam removals in the West (I'm familiar with the recent removal of the Elwha and Glines Canyon Dams) were in part to help increase abundance of another salmon species, Chinook (Oncorhynchus tshawytscha), although all five O. salmon species should benefit. The official reasons for dam removal actually had more to do with the fact that the dams are in a national park, and thus needed to be retrofitted to meet park requirements. It was less expensive to take them out.


Anyhow, there are a number of Chinook populations in particular that are considered endangered, and Chinook populations in general are smaller than pink populations. Differences in fish size, and spawning cycle, and life cycle in the home rivers. By the way, Chinook is the most prized because it has the best taste. I've eaten all five species for more than a decade, and can say this with certainty. Some people liek sockeye better, but each to their own. Pink is actually the lowest on the taste scale, next to chum.


So, to answer your assumption, right now there is a pink explosion. This has been known to happen because of their 2-year spawning cycle (Chinooks spawn every year depending on age group). However, not all salmon were "created equal." Again, there are five important species in the O. genus: Chinook, pink, chum, sockeye, and coho. They all have differing life cycles and levels of abundance. Chinooks in particular are decreasing in certain populations. Yes, over the past couple decades, there were shortages of various salmon populations. Hatcheries helped to bolster these populations, and prevented a complete collapse. However, now that some species are recovering (pinks), the hatcheries need to reevaluate how many fish of each species they are putting back into the system.

Charlotte Lenox
Charlotte Lenox

@Richard G. The situation you're referencing was one of complete unregulation... fisheries in the US, generally speaking, have gotten better about management, so I doubt we would see a boom-and-bust in the pink population because of whatever regulatory measures the fisheries choose. Not saying it won't happen, just that based on the current state of fisheries in this country, it's unlikely to happen.

Gerard Van der Leun
Gerard Van der Leun

@Richard G. You have to have lost some core ability for ratiocination to think that's a parallel. 


In general assume that everyone reading a Nat Geo board has heard of the  passenger pigeon and is not impressed by the reference.

Charlotte Lenox
Charlotte Lenox

@Aldo Leupold lol I'm in agreement with you there, even though humpies taste pretty lousy when compared to the kings... but it's still excellent, wild protein as far as I'm concerned.

Charlotte Lenox
Charlotte Lenox

@Bull Durham ... You're misunderstanding environmental science. Stop believing the media, and take a look at the source material--the actual reports and the data involved, written by the scientists themselves. The media distorts science on a regular basis, because the people tasked with summarizing scientific work aren't scientists themselves and thus misinterpret information, or only give an incomplete picture. Scientists are also frustrated at times because they struggle with making their research comprehensible to the public. This is why it often looks like they are making contradictory statements, especially about climate change, which is an enormously complex topic. I don't have the space here to even attempt a broad summary of it, but whether or not it is a natural or human-forced change (I believe it to be a combination), this doesn't change the fact that people in the near future are going to have to adapt. Sea levels are going to rise--they are rising right now. Weather patterns are going to change, not just on a local scale, but on a global one. Crop production with also change, and for the worst until we can figure out alternatives or improvements.


Business-as-usual will see these changes happen faster. Natural ecosystems as well as humans will have less time and more difficulty dealing with the after effects. Denial of these changes is stupid, and benefits no one. What astounds me is that people are still arguing whether or not the change is human-induced, as if this argument even matters anymore. It doesn't. What does matter is what we can do to prevent to worst changes from happening, and what we can do to adapt to the ones that are now irreversible. The lot of you at least acknowledge that climate is dynamic, and that it is currently changing. People have the power to make it worse, or make it better. THAT is what matters. How can it possibly be a bad thing to take care of the space you use to survive?

With regard to the salmon and seabirds, well--any sort of change in climate is detrimental to more species than not. Change benefits a select few species that can expand their ranges, or fill in vacated niches. But for most, change is bad in the short-term. Biodiversity thrives in times of stability. Stability means more time for species to evolve and fill new niches. Too much change upsets the system, and species must either adapt, or go extinct. Many go extinct, as history has shown. Pink salmon just happen to be one of the very few species that can take advantage of the change, along with their food source.

I shouldn't have to say it, but loss of biodiversity = bad for people, as well as the natural world.

Brian Allisob
Brian Allisob

Agreed, Durham. I long for the day when anything - any little thing - that occurs in the natural world is not attributed to climate change. Good lord, the climate has been changing ever since there was a climate at all. Species - all species, every single organism - have undergone changes in territory and density and existence itself since time began. Is it now impossible to observe any shift in population dynamics without attributing its causation to humans somehow shifting the clouds which circle the world? This hysteria must come to an end; I only hope it occurs sometime during the days I have left.

Herbert Curl
Herbert Curl

@Charlotte Lenox @Bull Durham  This is the most intelligent and well-reasoned comment on this thread so far. 


Earth's climate has been changing since its formation 3.8 B years ago, sometimes dramatically. There have been 5 major extinction events after which the "reset" button was pushed on evolution. 


In the couple million years that hominids have been around and million years that humans, and the few thousand years that "industrial man" has been around, we mammals have done more to change the ecology of Earth, and faster, than any of the preceding events. The last 200 years have seen the fastest changes caused by humans. It's happened so fast, in terms of generations, we didn't expect it, didn't suspect it and now, don't believe it.


We're constantly astonished (or disbelieving) that simple things like poisoning Bald Eagles and other birds, and then restoring them, overfishing and then creating a surplus of some species, inventing machinery using fossil fuel and then regretting it, could be happening. And that it's happening with no input or "vote" from the vast majority of the people of the world. 


"Increasing intelligence may be a lethal gene."
        ------Ernst Mayr - geneticist



KENNETH LANE
KENNETH LANE

@Brian Allisob  I am at a loss as to the "harm" aspect of attributing climate change dynamics to human activity.  I am not well trained but the dynamics we see today in ice reductions and sea levels seem cause for some alarm and inspections.

Water Colour
Water Colour

@Herbert Curl @Charlotte Lenox @Bull Durham  


All ecosystems have limits -- the north Pacific Ocean appears to be reaching its limit for salmon. Is that a bad thing? Maybe. 


As Charlotte_Lenox suggests, too much of a good thing can have negative impacts due to loss of biodiversity -- and that is what hatcheries are doing as they glut the sea with a genetically-diluted stock of low-grade fish that are too numerous to market at a price that makes fishing them worthwhile. "Hatch-22", they call it.  


Here is a good article summarizing the impacts of hatchery-production on wild salmon stocks -- sums up the past few decades: http://e360.yale.edu/feature/hatch-22_the_problem_with_the_pacific_salmon_resurgence/2335/


Onward..


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