By Hal Bernton • The Seattle Times

SAVOONGA, Alaska —

Derek Akeya hopes for calm waters and a lucrative catch when fishing in the Bering Sea that surrounds his island village.

But on this windy late summer day, waves toss about the boat as Akeya stands in the bow, straining to pull up a line of herring-baited hooks from the rocky bottom.

Instead of bringing aboard halibut — worth more than $5 a pound back on shore — this string of gear yields four large but far less valuable Pacific cod, voracious bottom feeders whose numbers in recent years have exploded in these northern reaches.

“There’s a lot more of them now, and it’s more than a little bit irritating,” Akeya says.

The cod have surged here from the south amid climatic changes unfolding with stunning speed.

For two years, the Bering Sea has been largely without winter ice, a development scientists modeling the warming impacts of greenhouse-gas pollution from fossil fuels once forecast would not occur until 2050.

This ice provided a giant platform for growing algae at the base of the food chain, and has been a significant contributor to the remarkable productivity of a body of water, stretching from Alaska to northeast Russia, that sustains some of the biggest fisheries on the planet.

Much of U.S. seafood comes from the Bering Sea, which generates income for an arc of communities that reaches from Savoonga to Seattle, where many of the boats that catch and process this bounty are home-ported.

Researchers now are uncertain when and to what extent the ice may return, and have scrambled to better understand the consequences of back-to-back years of its loss.

“There are very few places on the planet where environmental change is more apparent than Alaska,” said Robert Foy, director of the National Oceanic and Atmospheric Administration’s Alaska Fisheries Science Center. “When we talk about … sea ice, the changes we are seeing, they are on a massive scale.”

This summer, the pace of change quickened on shore as a heat wave contributed to the deaths of salmon before they could spawn, to wildfires that shrouded the city of Anchorage in smoke and to the melting of permafrost, which causes ground to shift and can create problems for buildings and roads.

Offshore, temperatures in some spots at the bottom of the northern Bering Sea this summer measured more than 12 degrees Fahrenheit higher than nine years earlier.

The warming supports the spread of toxic algae blooms, raising concerns about the impacts on marine life.

The Bering Sea changes brought about by the lack of winter ice represent “the ecosystem of the future,” said Phyllis Stabeno, a Seattle-­based oceanographer with the Pacific Marine Environmental Laboratory who has studied this body of water for 30 years.

The northern Bering Sea now abounds with cod as well as pollock, two big-volume commercial species once largely found hundreds of miles to the south.

Meanwhile, halibut in these waters have declined, and smelts — an important food for seabirds — have crashed.

Savoonga’s location on St. Lawrence Island, midway between Russia and mainland Alaska, gives its population a ringside seat to the sweeping changes in the Bering Sea.

“Our cliffs are sick,” said Delbert Pungowiyi, president of the Native Village of Savoonga, a tribal organization.

In harsh winters the ice used to extend south from the Bering Strait almost to the Alaska Peninsula. Even in milder years, it typically stretched for hundreds of miles.

The ice froze through the fall and winter, shedding very cold, very briny seawater that would sink and form a frigid layer down deep. Pollock, cod and many other species avoided the cold pool, and it often kept them from swimming north.

As the ice melted in the spring, it gave marine life a big boost. Blooms of the ice algae — known as phytoplankton — spread through a less-salty band of water close to the surface, which also was rich in other forms of algae. All of this was a buffet for zooplankton, tiny creatures such as copepods and krill that are rich in fats and are key food sources for young fish, birds and some marine mammals.

When there’s no ice, there are still later blooms of phytoplankton. But they support less-fatty zooplankton.

“The fish and seabirds are feeding on less-nutritious prey,” said Janet Duffy-Anderson, a federal research biologist at the Alaska Fisheries Science Center in Seattle.

Duffy-Anderson was a part of a team that looked at pollock after a five-year stretch of ice-free winters in the southeast Bering Sea, ending in 2005. Young pollock had lower survival rates, and the adult pollock population later dropped by more than 40%.

The study, Duffy-Anderson said, raises the possibility that the entire Bering Sea — once it permanently loses winter ice — will sustain far fewer fish.

As the winter ice thinned and retreated, the cold pool shrank. The past two summers, it almost disappeared. Without that barrier, some fish are now migrating north and scattering across broader areas as they search for food.

Federal trawl surveys show huge shifts.

Since 2010, summer cod have increased more than 20-fold and pollock more than 50-fold in the shallow northern Bering Sea, which narrows where Asia and North America reach out toward one another.

Scientists are uncertain whether this area can support all these fish, especially if the winter ice, and the algae that grows on it, fail to return.

But these fish seem to be on a long-term northern migration.

Overall, the center of the pollock population since 2012 has moved north an average of more than 18 miles a year.

“It is certainly one of the fastest (northward movements) I have heard of worldwide,” said Jim Thorson, an ecologist studying the loss of sea ice with NOAA Fisheries.

For crab fishermen who live by the northern Bering Sea, the loss of ice appears to be upending their livelihoods. Most are based in Nome.

Small suction dredges operate just offshore. Crabbers have made a living venturing onto the winter ice, where they cut holes to the water to catch king crab. In the open water of summer, they drop pots from more than 35 boats in harvests that in 2017 generated more than $2.5 million. But this year has been disastrous.

Without the traditional covering of ice, winter was a bust.

During the summer, crews failed to find much crab and fell far short of harvest limits.

“I typically have caught 23,000 pounds by now — but this summer, I have less than 5,000 pounds,” said Don Stiles, who fishes out of Nome.

Researchers say this scarcity could be because the crab — due to warming or other factors — moved out of their traditional harvest grounds, out of reach of the Nome fleet. Some crab may have been eaten by cod that have moved in.

As Stiles and other skippers searched for king crab this summer, they pulled up pots that were sometimes filled with a dozen or more cod.

“That’s a lot of cod,” Stiles said. “You see it coming, and you think, ‘Oh, no.’”

In the middle of July, after pulling up several pots containing only cod and a few starfish, he got so discouraged that he opted not to retrieve more than three dozen other pots. In late August, he returned to check them.

Many pots held cod. And there wasn’t much adult crab.