Global warming and hatcheries pumping billions of salmon into the North Pacific Ocean are combining to change the very nature of Alaska sockeye salmon, according to a peer-reviewed study published in Nature Ecology and Evolution this week.
Warming waters in the lakes of Bristol Bay have boosted plankton productivity and caused young salmon to grow faster than in the past, according to a team of scientists led by Timothy Cline of the University of Michigan.
As a result, more young sockeye are going to sea as one-year-old fish instead of spending two years in freshwater. Once at sea, however, the young sockeye face increased competition from pink salmon – many of them hatchery fish – for food.
A lack of food delays maturation and forces more sockeye to spend an extra year in the ocean before returning to spawn.
“The positive effects of climate change for earlier migration to the ocean, which may increase population productivity, are largely dampened by longer ocean residence,” the scientists concluded. “The evidence for overcrowding of salmon in the ocean and increased competition for resources has been gaining strength. Hatchery production has increased substantially since 1970, and there is high spatial and trophic overlap between sockeye, pink and chum salmon in the North Pacific.
“Growth and survival in North American salmon stocks have been shown to be negatively affected by hatchery-produced pink salmon.”
What this all means for the future of wild sockeye is unclear, but the study suggests humans are gambling with tens of thousands of years of evolution that allowed sockeye to adapt into various age classes to survive environmental catastrophes.
Human intervention at multiple levels – commercial harvests, hatcheries, and climate change – have combined to alter the shape of a salmon population historically comprised of fish that spend two years in freshwater and two years in the ocean – so-called 2.2s, and a mix of 1.2s, 1.3s, and 2.3s.
“These (human-driven) stressors combine to reduce the size-at-age of fish vulnerable to commercial fisheries and have increasingly favored a single-age class, potentially affecting the age class complexity that stabilizes this highly reliable resource,” the researchers said.
Money, money, money
The pink salmon now dominating the Pacific are Alaska’s most common salmon, and the bread-and-butter of the state fishing industry.
The Alaska record harvest of 272 million salmon in 2013 included more than 219 million pinks, or humpies as Alaskans often call the salmon that develop a distinct humpback when ready to spawn.
Hatcheries are a big part of the pink production.
“The hatchery harvests alone in both 2013 and 2015 were greater than the entire statewide commercial salmon harvest in every year prior to statehood except for seven years – 1918, 1926, 1934, 1936, 1937, 1938 and 1941,” Mark Stopha, who oversees the state’s private, non-profit hatcheries for Fish and Game, raved in the state’s May 2016 issue of Alaska Fish & Wildlife News.
Sockeye, however, remain Alaska’s most valuable salmon. Despite the 2013 bounty of humpies, the Alaska Department of Fish and Game that year reported that the statewide harvest of 29.3 million sockeye “narrowly held onto its position as the most valuable salmon species harvested in Alaska’s commercial salmon fisheries, with a statewide value of $284 million.”
Though the pink harvest was about seven and a half times bigger than the sockeye harvest, it was worth only $277 million.
Sockeye are four- to eight-pound fish with firm, flavorful, deep-red flesh. Pinks are three- to four-pound fish with softer, less flavorful, pinkish flesh.
Most sockeye are caught and sold fresh, or flash frozen for later sale in place of fresh fish. Most pink salmon are canned.
Because many of the pinks now return to Alaska hatcheries, however, they can be caught and handled with great efficiency, lowering overhead for both fishermen and processors.
These things, along with the valuable roe of female pinks, make the fish a solid, economic opportunity in a global market now dominated by farmed salmon.
A McDowell Group study commissioned by the Prince William Sound Aquaculture Corporation in September of last year estimated the value of that region’s ranched fish, primarily pink salmon, at almost $125 million per year.
There is no denying that hatcheries have been a godsend for the remote and wild Sound only about 50 miles southeast of the state’s largest city. A region that averaged a harvest of 3 million fish per year between 1951 and 1979,” now averages about 45 million pinks per year, a 15-fold increase over the historic catch, according to Fish and Game data. The catch hit a record high of 92.6 million in 2013.
Good for who?
A variety of studies have, however, raised questions as to whether what is good for the Sound is good for regions outside the Sound. The latest study adds to the concerns.
Its findings provide “evidence of negative impacts of hatchery augmentation on wild salmon stocks at the scale of the North Pacific, particularly through interaction with the effects of ongoing climate change in freshwater,” Cline wrote.
The study recognizes warming waters in Alaska lakes has increased salmon productivity, but “the competitive environment for salmon in the North Pacific Ocean has also changed, as the biomass of salmon doubled between 1960 and 2010.
“This increase is due in part to greater wild salmon abundance, but has been largely
driven by hatchery releases of Pacific salmon by the surrounding nations. Recent estimates attribute 40 percent of Pacific salmon abundance to hatchery-produced fish, although this estimate is conservative as hatchery fish that spawn naturally are not counted.
“These key changes in both the abiotic and biotic environment have the potential to shift the dominant life-history strategies of sockeye salmon as they complete their life cycles.”
The U.S. is the North Pacific leader in hatchery production, and Alaska – a state which banned fish farming in favor of ocean ranching – produces more than 90 percent of those fish, according to data compiled by the North Pacific Anadromous Fish Commission.
A 2017 study of the possible long-term effects from the Exxon Valdez Oil Spill first stumbled on evidence that high levels of hatchery pink salmon production in the Sound depressed returns of sockeye salmon to the Copper River.
The latest study is the first to suggest implications for Bristol Bay, the state’s largest sockeye fishery.
The state has defended its private, non-profit hatchery system run by collectives of commercial fishermen.
When the Kenai River Sportfishing Association last year tried to get the Alaska Board of Fisheries to freeze hatchery production at current levels until more is known about salmon interactions in the North Pacific, Bill Templin – the chief scientist for the Alaska Department of Fish and Game – poo-pooed previous studies suggesting hatchery fish might be an issue and argued the North Pacific ecosystem is so complex that it is impossible to ferret out hatchery effects on wild salmon.
The latest study joins those suggesting otherwise.
“Diversity in age composition plays a key role in reducing variability in salmon runs, with importance for fishers, communities and industry that rely on annual salmon returns,” it warns. “Age structure reduces year-to-year variability in runs to Bristol Bay by 50 percent compared to the scenario if runs were of a single age.
“A diversified age structure reduces cohort resonance, volatile recruitment and
other systematic drivers of variation in abundance. In Bristol Bay, increases in the proportion of salmon spending only one year in freshwater and competition in the ocean are favoring the 1.3 life-history type, which has increased in all systems. Climate trends that continue to cause shifts toward shorter freshwater residency and delayed ocean maturation could translate into reduced age structure diversity. In most river systems, where 1.3 was historically dominant, the age structure is already less diverse.”
Alaska has witnessed record, average salmon returns in recent years, but with as yet fully unexplained, annual oscillations.
After the mind-boggling, record harvest of 272 million salmon in 2013, the total catch fell to 152 million in 2014, a 44 percent drop. But it then rebounded to 263.5 million in 2015, which saw the second largest harvest on record. The pattern has continued since with a drop to 112 million in 2016; a climb back to 224.6 million in 2017, and then a drop to 114 million last year.
On a total harvest level, the shifts are being driven by pinks, the smallest and fastest growing of the five-salmon species harvested in Alaska. The pink catch last year was 40 million, less than 20 percent of the 2013 harvest.
Odd-year and even-year pinks are genetically distinct, and Canadian salmon researchers have suggested that a warming Gulf of Alaska may be “benefiting odd-year returning pink salmon more than even-year salmon, especially in the southern part of their range.”
The full influence of pinks on other salmon species is still being debated, but there is growing evidence the North Pacific is enduring significant changes at the hands of man.
Dots can usually be connected using common sense much faster than connecting them with peer-reviewed studies. So … dots that likely connect: billions of pinks pumped into the ocean – food chain disrupted – murres die off – gray whales die off – other species of salmon, like kings, die off.
Gotta love the comm fish and hatchery apologists on this site who state “No whining!” in caps and state everything is cool, to a peer reviewed report that documents impact on Bristol Bay sockeye from both freshwater and saltwater changes – specifically warming freshwater conditions and increased good competition from pink salmon in the ocean.
All outmigrating salmon stocks in 2015 to the Gulf of Alaska suffered poor survival, be it pinks, sockeye, chum, silver or kings, and the adult returns were very poor.
The 2016 economic disaster declaration for Gulf of Alaska pinks put $50 million in compensation to comm fish processors and harvesters. Very little o that money is going to research why the ocean survival of outmigrating salmon in 2015 was so poor.
However, there has been no similar compensation for other salmon fisheries that were depressed in returns for other salmon species in subsequent year and returns in 2017 and 2018 (sockeye and kings in particular) and for kings in 2019.
The reason sockeye will do better in 2019 than in 2017 or 2018 is that the impact from 2015 has moved through the returns. Kings returns are still being impacted, as evidence by all the closures and restrictions to catch and release for king fishing this year.
And the poor king forecast will impact the time and area fishing for the commercial east side set net fishery.
So while sockeye fishing on the Copper River will be better, other salmon fisheries in the South central area are still feeling impacts.
And the lack of funding for better research overall in the Gulf of Alaska for salmon and the continuing poor returns statewide for kings is a disgrace.
Keep up the good work Craig for highlighting these issues. We will never read about them in the canned commercial fishing press releases and cheerleading known as fish radio and it’s newspaper companion
pieces elsewhere in Alaska media.
This one line you wrote sums up the whole 5 Billion hatchery fish added to the Pacific each year…
“…the study suggests humans are gambling with tens of thousands of years of evolution…”
With radiation from Fukushima and plastics filling the bellies of whales throughout the Sea…
We are seeing a destruction of the Biosphere by Globalist who buy and trade our resources like junk stocks on Wallstreet.
This latest crisis with dead whales only goes to further prove that the Ocean Ecosystem is sadly becoming a mono culture of fish ranching and waste.
“Federal authorities are calling the spike in gray whale deaths observed up and down the West Coast this year an “unusual mortality event” that biologists will be investigating.”
All declaring an “unusual mortality event” does is it forms an investigative team and opens access to some additional funding. It’s strange because just two days ago, with the same number of dead whales the same scientists quoted in the story you linked were reported as saying the following “the gray whale population has likely reached carrying capacity, meaning the number of individuals the ocean can support with the available food supply.” It was also reported that “Alaska typically sees between zero and three dead whale strandings by the end of the May, so this year’s count is “pretty much in the normal range, maybe just slightly above,” Speegle said.” https://www.adn.com/alaska-news/wildlife/2019/05/29/fourth-dead-gray-whale-to-wash-up-in-alaska-spotted-on-the-kenai-peninsula/
If only 10% of dead whales are found in any year, as one of the biologists in the article states, then it’s certainly possible that in any given year more dead whales could wash ashore and be found even if fewer whales actually died than in previous years.
I find it strange that just two days after saying we are in the normal range or maybe slightly above that they declare they need additional funding. Of course calling this a crisis at this point is extremely premature and sensationalistic and ,counter to your claim, it proves nothing.
I cannot speak for that scientist, but I will say many scientists do change their educated opinions after more data or observations leads them to form new conclusions.
Maybe it was something seen on the autopsy of previous dead whales he discovered?
In Italy and the Philippines we are seeing large amounts of plastic in the dead sperm whales stomach?
What was found in the stomach’s of the dead whales on our coastline?
Not much is reported on that.
“There are five sperm whales beached in the last five months on the Italian coasts,” she said, according to a translation. “In the stomach of the pregnant female found in March in Sardinia, even 22 kilograms of plastic were found.
The sea is sending us a cry of alarm, a desperate SOS. We must intervene immediately to save the wonderful creatures that inhabit it.”
Not this shit again! Stop the Global Whining!
I couldn’t get past the first paragraph. When I see “Global Warming” I know the story is a fabrication. Bristol Bay has been heated the last 5yrs from el Nino. Oh, I know “Global Warming we are all going to die in 12yrs” sells but, it is all silly nonsense. Craig, can you please do a story on Alaska’s long running historic el Nino warming and it’s effects?
” So what has happened?
A bunch of things, to be honest. First, if you haven’t heard, we are in a pretty historic El Niño, which usually correlates to above-normal temperatures across central and eastern Alaska. On top of that, the Aleutian low pressure system, a semi-permanent low that camps out near, you guessed it, the Aleutians during the winter was much stronger than average. In fact, according to one dataset, mean sea level pressures averaged over the entire winter, were the lowest on record (1948-present).
With counter-clockwise air flow around the low, southeasterly winds brought warm, moist air to Alaska. So why was it so dry in some places? Well, that moist air hit higher mountain elevations along the southern coast of Alaska, dropping rain and snow, leaving little moisture left for interior areas. In fact, coastal windward areas around Anchorage observed above-normal precipitation this winter.”
Can someone tell me where the “Global Iceage” of the 1970’s went?
Sorry, I have to disagree!
Your stated most pinks are canned. That may have true 5 years ago, though great strides have been made in selling H&G pinks to China for reprocessing. Also, frozen pink fillet market to Eastern Europe, have surged. In Cordova, where in the past, there was only a 73% recovery on pink salmon, now with two cold pressed oil factories, 97-98% of the fish is used. Only some bones and skin make up that 2-3%. Shelf stable fish oil is the byproduct, that is then shipped to a company, that puts oil in capsules. That is huge! All the processors in BB, need to invest in this new technology and get maximum profit from the fish. The pinks are generating lots of dollars to the municipalities, villages, towns and cities surrounding PWS: Cordova, Valdez, Tatitlek, Whittier, Chenega, Seward, Homer, Kenai & Anchorage, all share in the bounty from hatchery pink salmon, from PWS.
And talking about sockeye returns, Bristol Bay has had three blockbuster seasons, in a row, with last year having one of the largest returns and harvest ever recorded in BB. Plus, this same blog implied last year, that the hatchery pinks, helped cause the CR sockeye dismal return in 2017.
No one is celebrating or talking about the decent sockeye return to the Copper this year.
The upriver subsistence, Pu & sport users will also have a good season.
No whining this year!
When you have Mother Nature figured out, please let me know.
Great, well thought out response James. Except the last paragraph you really went off the rails there, hatchery fish are not a part of Mother Nature.
Good comment James !