Alaskan salmon are decreasing in size thanks to climate change and competition, study says
By Paul Homewood
It is not only climate science which has become corrupted, but climate change has also corrupted many unrelated subjects as well.
This study on salmon, for instance, seems well researched, but cannot resist the urge (or maybe pressure) to put part of the blame on climate change, without as far as I can see any evidence whatsoever:
Alaskan salmon are getting smaller due to climate change and competition, according to a new study.
The authors researched over six decades of data from the Alaska Department of Fish and Game — from 1957 to 2018 — on over 12.5 million fish.
The primary cause of the declining body size of salmon, according to the study, is that the fish are spending less time out in the open Pacific Ocean.
"We saw a strong and consistent pattern that the salmon are returning to the rivers younger than they did historically," Eric Palkovacs, a professor at UC Santa Cruz and a corresponding author of the study, said in a news release.
"It seems that the ocean is becoming a riskier place to be," he said.
The study looked at four species of salmon — Chinook, chum, coho and sockeye — throughout Alaska where residents have noticed a decrease in salmon size.
Besides spawning at younger ages, climate change and competition from the growing numbers of wild and hatchery salmon are also significant factors in salmon size reduction, according to the study.
"We know that climate drives changes in ocean productivity, and we see a consistent signal of climate factors associated with decreasing salmon size," Palkovacs said.
"Another consistent association is with the abundance of salmon in the ocean, especially pink salmon," Palkovacs said. "Their abundance in the North Pacific is at historic highs due in part to hatchery production in Alaska and Asia, and they compete with other salmon for food."
Krista Oke, an author of the study and a scientist at the University of Alaska, Fairbanks, said that the next thing the researchers want to analyze is what is causing the shift in the ocean itself.
https://edition.cnn.com/2020/08/20/us/alaskan-salmon-size-decreasing-trnd-scn/index.html
This is the Abstract:
https://www.nature.com/articles/s41467-020-17726-z#article-info
So, we are told, declines in salmon size, primarily resulting from shifting age structure, are associated with climate .
Yet a full search of the detailed paper for mention of climate change only finds:
In other words, there are lots of maybes and talk of modelling. Yet the results do not even provide evidence of any metabolic effects from temperature.
And the best that they can come up is that climate change might affect some species, but not others. Hardly a ringing endorsement for their little theory.
They have no clue at all of any mechanism which might explain why climate change could have had the effects seen, let alone proper statistical analysis to back it up. All we get is perhaps occurring through climate-mediated changes in food availability or quality.
But until proper, fact based evidence is provided of these changes and proof offered that they are caused by climate change, their assertions remain just an unproven theory. And unproven theories should not be used as the basis for a scientific paper.
As with most of these sort of nature studies, there are obvious and clear cut reasons for the decline in salmon, as the paper itself emphasises. Notably increased competition from both wild and hatchery salmon. There is simply no reason to invoke climate change, for which there is no evidence.
The clue however lies in the final paragraph of the article:
Krista Oke, an author of the study and a scientist at the University of Alaska, Fairbanks, said that the next thing the researchers want to analyze is what is causing the shift in the ocean itself.
In other words, we have no idea what is happening, but chuck us some more money and we’ll keep looking. And, as we know, talk of climate change is guaranteed to up the ante!
Comments are closed.
NOT A LOT OF PEOPLE KNOW THAT 
To the researchers and those who published their work, Question 1: what evidence is there that climate has changed? Question 2: what kind of climate change is being referred to e.g.hotter, colder, more tropical? Question 3: are they saying climate change is human-caused or natural? Question 4: what evidence is there that links smaller salmon to the climate change being talked about. A criticism could be made that unclear implications and unevidenced assumptions are dreadful in any scientific publication.
1) 97% of scientists agree.
2) It’s bad, very bad & will get worse, 97% of scientists agree.
3) Us, 97% of scientists agree.
4) Because.
I think that sums it up.
you forgot to ask mickey and minny about how they are fighting back against the climate crises. They have been icons in society for years and years and know all about the dangers of erosion and stuff like that
Lots of dancing around the situation but no real “theory” and trying to become revalent in todays world and climate culture (not science). Just like everything else the enviro-mental (pun intended) nut jobs have pulled out of their arses for the last several decades. I have no taste for salmon, anyway. Catfish is my fav grilled or deep fried spicy with lots of sauce and plenty of MGD cold brew.
“We know that climate drives changes in ocean productivity…”
Can we assume you mean increases in primary productivity promoted by added atmospheric CO2? More food in the surface waters for fish like salmon?
And biological activity increases with temperature.
As someone who has been on quite a number of Alaskan salmon-based fishing holidays over the last 20+ years, I’m sure this a load of steaming carp. I’m not even sure, for instance, that many of the five species of Pacific salmon are farmed. Pinks certainly are, but the rest? If no others, and given that releases of farmed fish aren’t common, why mention farming at all?
Anyhow, I will send it on to some fellow fishers (including a couple in AK) and come back with any comments.
A point worth making now, however, is that the weather conditions both leading up to, and during my trips have been wildly different in terms of wind, rain and temperature, as you would expect in sub-Arctic environments. The temperature variations alone (often 60C+ during any calendar year and 15C to 20C between my trips) are of a completely different order to the any supposed average temperature change due to “climate change”. In context, the latter are simply trivial and would not affect salmon size (fish that spend most of their lives in cold seas anyway).
Got my replies back from AK. Yep – it’s nonsense. This was a typical response, in this case from a man whose family has run wilderness fishing camps for two generations:
“We have not seen anything even close to this.”
I rest my case m’lud.
Salmon and the weather/climate:
“The PDO index is defined as the leading principal component of North Pacific monthly sea surface temperature variability (poleward of 20N for the 1900–93 period). A summary of the PDO is given in D’Aleo and Easterbrook (2011 and this volume). It was discovered in the mid-1990s by fisheries scientists studying the relationship between Alaska salmon runs, Pacific Ocean temperatures, and climate. Hare (1996) and Mantua et al. (1997) found that cyclical variations in salmon and other fisheries correlated with warm/cool changes in Pacific Ocean temperatures that followed a regular pattern. Each warm PDO phase lasted about 25–30 years and then switched to the cool mode for 25–30 years.”
The PDO is a very big deal. During the cold PDO (when we have more LA Nina’s). Salmon populations in Alaska and the North American Pacific Coast explode. More fish, bigger fish: Spawning runs hit new records in the Fraser River, BC in I believe 2010.
Everyone bemoans the supposedly, ever declining, Salmon populations, then the PDO shifts and the Salmon return. So yes, salmon populations are definitely effected by the PDO and if you believe everything is changing, including the PDO, because of CO2 emissions, then of course climate change is the culprit. Besides if you babble about climate change in your paper you get funding for your work. So everyone has to babble about it – even the silent agnostics – they don’t want to be ostracized by their colleagues & administrators.
Scientists follow the money and want to be liked by their colleagues BUT the ideology with the money happens to be anti-growth and anti-human, nasty and destructive. So, does that mean scientists are right to promote the propaganda which enforces via national legislation the anti-growth, anti-human, nasty and destructive ideology?
My scathing comments are for those who “reviewed” this and allowed it through!
It is simple.. The top salmon is small. the bottom salmon is far away……..
‘”It seems that the ocean is becoming a riskier place to be,” he said.’
Your theory being that they go back to spawn earlier because they are skeert?
‘The study looked at four species of salmon — Chinook, chum, coho and sockeye — throughout Alaska where residents have noticed a decrease in salmon size.’
Perhaps you quacks should have looked at some WEATHER data, too.
‘We know that climate drives changes in ocean productivity’
My God, this is junk science! Smaller size fish has double ought zero bearing on productivity. More smaller fish could even be an increase in productivity. This is awful!
‘We see a consistent signal of climate factors associated with decreasing salmon size,” Palkovacs said.’
Climate factors. Does he mean “weather?” And what ‘consistent signal of climate factors’ are you seeing? You studied fish sizes. You didn’t study weather. Attribution to ‘climate change’ is corruption.
17 co signers. Generally, the more authors, the more likely junk. 17 is a lot.
‘For harvested species subject to multiple stressors, limited understanding of the causes and consequences of size declines impedes prediction, prevention, and mitigation.’
Wat?
‘Downsizing of organisms is a global concern, and current trends may pose substantial risks for nature and people.’
Ahhh . . . the next big thang. Right behind ocean acidification.
“17 co-signers”: It’s all to do with Google Scholar and paper counts. Mann did the same, adding his name to lots of papers so that he could claim authority based on quantity rather than quality.
From the other side adding the name of one of the leading climate alarmists to your paper as in Mann, helps to add prestige in the alarmist world and with the legacy media.
I thought the small salmon had been genetically modified to fit in the tins !!!
Very interesting idea) …
No they are just dealing with their obesity problem.
Natural selection in action , they are beating sardines at their game
Origins of American product advertising regulations date back generations ago to a white salmon producer advertising that his salmon was “Guaranteed not to turn pink in the can.”
BWTM: Pink salmon producers counter: “Guaranteed no bleach used in processing.”
I can only speak about trout (related species) but wherever I have fished for natural brownies the adult size has always been a function of the availability of food – they adjust entirely naturally to their environment.
Nice to see that these salmon are dealing with their obesity problem.
“competition from the growing numbers of wild and hatchery salmon ”
Does this mean more wild salmon are getting back into the ocean? Does it mean that there has been no increase in the numbers of oceanic predators? Presumably competition from farmed salmon is from escapees?
There are many potential reasons for this change which are far more likely than climate change. Fewer predators in the ocean, more releases of hatchlings, fewer predators on returning salmon meaning more reaching spawning grounds.
50+ years ago I used to go fishing for Brown Trout in a local river. At that time there were a lot of not particularly large trout along the stretch we fished. Thirty years later the population had dropped quite significantly but size of individual fish had increased significantly. I have no idea why the change, probably climate change I now realise
Paul, I quote from the text associated with Fig 3: “Changes in population mean length are primarily due to changing age composition (gray) and to a much lesser extent changing size-at-age (black)”.
They use some complicated language to say simple things but this says that the sampled fish are smaller because they are younger!
Also from Fig 1. Across Alaska, average salmon body size has gotten smaller
Since WHEN has “gotten” been accepted language in science writing?
Also how about them being fished out as a cause for the older ones to be less represented? How about also that there is a population explosion, warmer water means more of everything in the food chain!
Age may well be the answer Jonathan, and it’s the same the world over as pretty much all regional rod-caught records are at least decades old. The point is, the more years the salmon stay out at sea before running the rivers – and no, there isn’t a rigid set time to return – the bigger they will be. The monster specimens are all fish that spent several years out at sea growing before returning to the rivers. However, with ever-increasing netting pressure out at sea, the longer a salmon stays out at sea the more likely it is to be netted at sea and never return.
There’s another nasty twist to that too – genetics. If you have a sub-population that wants to stay at sea for years and grow large, if it spawns the youngsters will inherit those traits. If, as may well be the case, the great majority of larger salmon get netted out before returning, then the only ones that escape and spawn will be younger (and smaller). Thus, the intensity of netting in effect selectively breeds smaller fish who spawn younger.
Of course this wasn’t mentioned as a possibility in the study, that would have involved accumulating knowledge.
Are similar changes recognised in the Pacific salmon that are found in the waters of Argentina and Chile?
David,
I stand to be corrected on this but I believe that all Pacific salmon species are native only to the Pacific northern hemisphere, and higher latitudes at that.
The Pacific populations of Chile and the Atlantic populations of Pacific salmon in Argentina are thus introduced / farm escapees and are recent and pretty limited. Thus, I don’t think there is sufficient historic data from which to draw conclusions.
Good point, Ian; I realise that numerically the south Atlantic population is insignificant compared with the north Atlantic. I know that 30kg+ fish are caught each year in rivers running into Argentina’s Lago Argentino.
“This study on salmon, for instance, seems well researched, but cannot resist the urge (or maybe pressure) to put part of the blame on climate change, without as far as I can see any evidence whatsoever:”
The other fearful impact of climate change is what it has done to the field of reaearch. No matter what the topic it boils down to the horror of climate change.
https://tambonthongchai.com/2018/06/21/climate-change-impacts1/
Not to mention the explosion of the seal population…….
Are there any corners of science that haven’t become corrupted?
And blah blah blah…
Same old, same old.
One of the undocumented and sketchy ideas going the rounds is that ocean marine populations are starving. That would certainly mean smaller catch.
That picture is misleading. The larger salmon in the picture is one of a male Coho salmon. They are generally larger and actually increase in size as they reach spawning maturity in the rivers. They develop a slight bump behind the head and a large hooked snout.
The smaller fish in the picture is a female and it is rare to see one over 12 pounds. They do not develop the same bump and hooked snout a male Coho salmon will. I’ve caught males over 20 pounds but never females.
From my experience of over 20 years as a salmon fisherman, I can confirm that some salmon may be getting smaller but not because of climate change. The pictures are quite typical of a male and female Coho salmon. This same kind of transformation happens with Chum and Pink salmon. Only Chinook salmon don’t see these kinds of severe bodily changes. The males will get slightly larger as they reach spawning maturity and will also develop a gnarly upper jaw but that’s about it. No bump of any significance develops.
As for size, in nature, the ‘jacks’ will compete for spawning with the mature male salmon and will often times release their milk along with the mature male salmon. For those that don’t know, a jack is a male salmon that returns early, is relatively small, less than 24 inches in length for a Chinook and less than 20 inches for a Coho. Some years you see a large return of jacks in the mix. Some years, not so much.
As for hatcheries, you will often get a scenario where the workers will usually by-pass the larger salmon and use smaller fish to spawn the eggs. The larger fish are hard to handle and no one wants to hold a 50 pound Chinook salmon while fertilizing the eggs from a female salmon. So, what you get over time are more and more small sized fish since the larger fish are left out. This same scenario can play out in nature but not because of human selection…The jacks are just cunning and quick.
You can ask anyone who works the hatcheries or is in the business and they will tell you that this is common practice. This is in reference to Washington state only since that is where I’ve done the vast majority of my fishing and growing up on the rivers and streams of that beautiful state. I’ve also caught many a salmon in Oregon and Alaska.
Many readers here may not know but a very common fishing practice in the North West of America is called gill net fishing. Gill nets catch fish by catching them by the gills as they attempt to swim through the net hanging in the water. Often the nets are colored in a manner to make it hard for the fish to see.
The fish moves forward into the net as far as it can go and then is stopped by the size of the opening. When it tries to back out of the net, the gills which were flattened by the net pressure when going forward now catch on the net mesh because they normally protrude slightly. A fish too large for the mesh of the net will not make enough progress through the net to allow his gills which are comparatively far back from the head, to become ensnared when backing up. He will bump into the net, not make it into the net beyond his head, escape the net and then jump over it or try and go around it.
The gill net fisherman makes a bet when choosing which net to set. A net mesh with large openings will allow small fish to pass through unimpeded but provide him with large salmon. A net mesh that is very small will catch only small fish. Big fish are worth more than small fish obviously but a lot of small fish are worth more than just a few big ones. Generally, the fisherman makes his choice on the basis of an estimate of the likely typical size of the fish in the first few catches of a given run of fish. Sometimes a fisherman will set their size adjusted net in a manner that catches fish that made it past another fisherman with a known size of net. Big mesh net behind a small mesh net. Small mesh net upstream of a large mesh net.
The final consideration is that the regulators keep a run closed to until they have done a few test sets themselves to see what that particular run is composed of. Then the regulators mandate the size of net mesh allowed. It definitely is not always apparent what the strategy of the regulators is when they establish the regulations which can change from day to day.
Just like when you regularly mow a lawn with a large number of dandelions of various sizes, pretty soon only short ones grow back. There is no doubt that heavy fishing of particular run by a standard size of net will eventually impact the size of the fish in returning runs. That doesn’t mean that is the only factor or even the main factor associated with the changing of the typical size of fish in a run. But depending on the regulator, it can be a very important consideration.
I note that the effects of the regulators acting on the advice of claimed fish _experts_ is totally ignored in this report.