The intense marine heat wave conditions that began roiling the Bering Sea in about 2016 resulted in the lowest winter sea ice extent measured in 150 years, widespread bird and marine mammal die-offs, a drastic shift in fish populations and a crash of snow crab stocks.

Now new research is tying the marine heat wave to the recent collapse of Yukon River chinook salmon.

A study published in April, written by scientists at the National Oceanic and Atmospheric Administration’s Alaska Fisheries Science Center and University of Alaska Fairbanks, showed the correlation between the extreme heat wave conditions and the nosedive in Yukon River chinook stocks. The heat wave was accompanied by a dramatic increase in deaths of older juvenile and adult chinook that, had they survived, would have returned from the ocean to freshwater spawning grounds, the study found.

The study was published in the journal Ecological Applications.

The Yukon River’s runs of chinook, also called king salmon, have been in a long-term decline since their past heyday, when they numbered in the hundreds of thousands and the river was one of the biggest sources of that salmon species.

The sharp downturn in recent years resulted in a 2022 return that was the lowest on record. Widespread fishery closures have been in effect for years along the Yukon River system in both Alaska and Canada.

The study evaluated four general reasons for the sharp decline: poor juvenile “recruitment” into the ocean, which refers to the successful migration of surviving juvenile fish from freshwater; deaths of fish in the marine environment at the start of their migration back to freshwater; harvests that target the salmon; and bycatch, the unintentional harvest of salmon by commercial fishing vessels targeting other species, such as pollock.

Poor juvenile recruitment emerged as an important factor, which was to be expected, the study said.

“Not surprisingly, we found evidence to suggest that impacts operating in the early life stages have likely contributed to declines in run sizes over the past two decades, which is consistent with previous research,” NOAA Fisheries researcher Lukas DeFilippo, the lead author, said in a statement.

But the information about spiking mortality among adults and older juveniles was new, the NOAA scientists said. That new trend represents “an apparent shift in the critical life history stages and processes” for Yukon River chinook, and a potential bottleneck limiting population recovery, the study said.

Exactly how the heat wave conditions caused deaths of salmon at sea is yet to be determined, the study said. It listed several factors that could have worked in combination, including lack of suitable prey, infections by the parasite Ichthyophonus and other diseases, as well as increased energy demands brought on by warmer temperatures.

Harvests, either intentional or as bycatch, did not emerge as important factors in the recent Yukon chinook declines, the study found.

The study contained some warnings.

Even though the marine heat wave conditions have eased, the abundance of prey that salmon need in the ocean has not returned to normal, it noted. And mortality rates in those later life stages continue to be higher than they were prior to the latest heat wave.

And the heat problems for older salmon are likely to become more common in years to come, the study said.

“Given that marine heatwaves are expected to become more frequent and severe with continued warming . . . similar rises in mortality—and concomitant limitation of productivity and recovery potential—as described here could become increasingly common in the future,” the study said.

An earlier study by NOAA Fisheries and the Alaska Department of Fish and Game tied successive heatwaves in both the Bering Sea and Gulf of Alaska to sharp declines in chum salmon stocks. That 2023 study also pointed to higher mortality out in the ocean.

Originally published by the Alaska Beacon, an independent, nonpartisan news organization that covers Alaska state government.

As the fight for control of the U.S. Senate grows increasingly competitive, eyes are turning north to Alaska and a contest pitting, among its contestants, Dan Sullivan vs. Dan Sullivan — and, no, it’s not about a candidate living a double life or wrestling demons within himself.

Confused?

That may be the point.

Daniel S. Sullivan is Alaska’s two-term Republican senator. He’s seeking reelection in November.

Daniel J. Sullivan is a retired school teacher and political novice. He calls himself an independent Republican cut from the same polar-fleece lining as the state’s maverick GOP senator, Lisa Murkowski.

Political handicappers give Daniel J. Sullivan little chance of winning the highly competitive race. So is there some other reason he’s running? Is his presence on the ballot intended to draw enough befuddled voters away from the incumbent to elect his Democratic challenger, former Rep. Mary Peltola?

That’s what Republicans think. And you don’t have to be standing on the banks of the Kenai River to smell something fishy.

When Daniel J. Sullivan launched his campaign in May, he did so as plain old “Dan Sullivan,” with a website closely resembling that of the incumbent. The press release announcing his candidacy was written by one “Amber Lee.” There is an Alaska political strategist named Amber Lee who has supported Peltola in the past.

(For such a sparsely populated state, there sure are a lot of doppelgangers in this political saga.)

Election officials say Daniel J. Sullivan asked to appear on the ballot as a Republican, even though he hadn’t previously been affiliated with the party. In fact, over the years he’d contributed money to Democrats, including Peltola. He also asked to be identified on the ballot as “Dan S. Sullivan” before changing his mind, an attorney for the state told Alaska’s Supreme Court, which took up the matter late last month.

“That’s not an innocent mistake, or random mistake,” Chris Murray told the justices. “There’s a lot of other letters in the alphabet that could have been a typo.”

The political consultant Amber Lee declined to comment when reached by the Anchorage Daily News. She did not respond to an email from your friendly political columnist.

For his part, Daniel J. Sullivan denied any malice or mischievous intent.

“This is my choice,” he told the Associated Press. He said he had no contact with Peltola’s campaign — “zero, none, zilch” — and denied anyone from the state Democratic Party or any national Democratic operatives had contacted him to run.

Peltola’s campaign has adamantly denied any involvement. So, too, have the Alaska Democratic Party and the Democrat’s national Senate campaign committee.

After an investigation, Daniel J. Sullivan was removed from the Aug. 18 primary ballot. Carol Beecher, head of Alaska’s Division of Elections, said his candidacy was intended to “confuse or mislead” voters.

But the state’s high court overturned that decision, instructing elections officials to figure out a way to keep Daniel J. Sullivan’s name on the ballot “within the confines of existing Alaska ballot design law.”

It’s been nearly 20 years since the state sent a Democrat to the U.S. Senate, but this election looks to offer the party its best shot in years, thanks to Peltola.

Jessica Taylor, of the nonpartisan Cook Political Report, called her “the ideal recruit,” given Peltola’s fundraising prowess and her ability to outperform other Democrats by avoiding the toxic taint of the national party. (Peltola’s slogan —”Fish, family and freedom” — is about as far removed from the Whole Foods-shopping, Prius-driving Democratic image as it gets.)

Democrats need to win four seats in November to take control of the Senate, from a menu that includes Alaska, Iowa, Maine, North Carolina, Ohio and Texas while, at the same time, hanging on to contested Senate seats in Georgia, Michigan, Minnesota and New Hampshire. The Cook Political Report rates Alaska as one of the few toss-up races in the bunch.

The state has a ranked-choice election system in which the top four vote-getters advance to November. Ivan Moore, who does nonpartisan polling in Alaska, said that system virtually ensures Sullivan and Sullivan will face off against each other in a runoff that includes Peltola. At that point, Moore suggested, the choice to most voters will be clear.

Under the solution devised by state election officials, the senator will be listed as “Sullivan, Dan S.” and as “(Registered Republican) Incumbent.” His challenger will be identified as “Sullivan, Daniel J. Jr.” with no party affiliation.

“I imagine there’s some people out there who don’t know what the word ‘incumbent’ means,” Moore said. “But I find it pretty hard to believe that people who are dead set on voting for Dan S. Sullivan, the senator, are going to go in the voting booth and vote for the wrong person when Dan S. has the word ‘incumbent’ next to his name and Dan J. doesn’t have any party affiliation.”

Political hijinks are nothing new. But the level of partisan gamesmanship seems to be growing as the old saying about all being far in love and war is increasingly applied to campaigns and elections.

It was something of a novelty in 2002 when Democrats meddled in the California Republican primary to promote their preferred candidate. Now it’s common practice.

Redistricting, or redrawing the nation’s congressional lines to reflect changes in population, used to occur once a decade following the national census. But spurred by President Trump, the last year has seen an arms race among states, including California, which gerrymandered their political maps to boost a preferred party and, essentially, decide House races before a single ballot is cast.

Politics, another old saying goes, ain’t beanbag.

But it doesn’t have to be this slanted and cynical. There’s no need for fishy-smelling candidates like Daniel J. Sullivan.

High School

Legion Baseball

Sunday

Issaquah (WA) 7, Wasilla 5

Monday

Dimond 14, Eagle River 4

West 13, Kenai 4

Service 2, East 1

Tuesday

Roseburg (OR) 16, Wasilla 5

Kenai 7, Dimond 2

Kenai 15, Dimond 4

Palmer 5, Service 4

Palmer 20, Service 11

Chugiak 8, East 7

South 3, Ketchikan 1

Fairbanks 10, Chena River 4

Wednesday

West 4, Palmer 3

Chugiak 13, Eagle River 3

South 4, Ketchikan 3

Ketchikan 4, South 1

Thursday

Service 2, Dimond 1

Ketchikan 9, South 6

Friday

Wasilla 20, Dimond 4

Palmer 11, Eagle River 5

Auke Bay 12, East 2

Fairbanks 13, Chena River 5

Kenai 15, West 5

Kenai 24, West 8

Saturday

Chena River vs. Fairbanks (Late)

East vs. Auke Bay (Late)

Auke Bay vs. East (Late)

Palmer vs. Wasilla (Late)

Alaska Baseball League

Sunday

Mat-Su Miners 7, Anchorage Bucs 4

Chugiak-Eagle River Chinooks 18, Peninsula Oilers 7

Monday

Mat-Su Miners 14, Anchorage Glacier Pilots 3

Peninsula Oilers 11, Chugiak-Eagle River Chinooks 4

Tuesday

Anchorage Bucs 8, Anchorage Glacier Pilots 7

Peninsula Oilers 7, Chugiak-Eagle River Chinooks 6

Wednesday

Mat-Su Miners 10, Anchorage Glacier Pilots 0

Chugiak-Eagle River Chinooks 5, Peninsula Oilers 3

Thursday

Peninsula Oilers 6, Chugiak-Eagle River Chinooks 5

Mat-Su Miners 7, Anchorage Glacier Pilots 2

Friday

Anchorage Bucs 2, Mat-Su Miners 0

Saturday

Anchorage Bucs vs. Anchorage Glacier Pilots (Late)

Mat-Su Miners vs. Peninsula Oilers (Late)