In Alaska, Summer’s Getting Too Hot for the Salmon Run | WIRED
06.13.2020 08:00 AM
Photograph: Scott Steindorf/Getty Images
This story originally appeared in High Country News and is part of the Climate Desk collaboration.
Unable to wet their nets and unsure when the fishery would reopen, Ugashik fishermen bided their time at seasonal camps, looking on as jumpers pocked the water all day long. “You’re pretty much watching your income go by,” Catie Bursch, a commercial setnetter on the Ugashik, said later. As Bristol Bay fishermen gear up for this year’s salmon season—one beset by fears that Covid-19 could overwhelm this remote region as thousands of seasonal workers from across the world descend on fishing communities with scant medical resources—they must also contend with a slower-moving hazard: the warming temperatures that threaten a $1.5 billion industry and the people it supports.
Every year, millions of salmon return to the Bristol Bay watershed on their annual summer migration to the headwaters where they spawn. This 250-mile-long nook in the Bering Sea is largely undeveloped—an area the size of Iceland, riddled with lakes, streams and wetlands that provide some of the planet’s best habitat for anadromous fish.
The Ugashik is a muddy world, where fishermen slog through knee-deep muck to secure nets along the edge of the river at low tide. A single net can yield thousands of pounds of salmon, which fishermen pick by hand from small open skiffs and then deliver to buyers on tenders anchored downstream. Some of the Ugashik setnetters have fished here each summer for decades, living in plywood bunkhouses in a dozen or so camps, bathing in handmade saunas, and riding four-wheelers into Pilot Point, a village of fewer than 100 residents, where milk costs $20 per gallon.
In addition to being the region’s economic driver, salmon represent a primary food source for the residents in remote towns and villages, most of whom are Yup’ik, Dena’ina, and Alutiiq. Each summer, Mark Kosbruk, an Alutiiq setnet fisherman on the Ugashik, puts up about 200 fish—canned, smoked, dried, salted—for home use. Last summer’s closure was “nerve-wracking,” Kosbruk told me recently. Dogged by the concern that he might not get to fish at all, Kosbruk fixed everything he could around his camp, topped off all of his engines with oil, then waited.
The state stipulates that water temperature must not exceed 59 degrees Fahrenheit in order for salmon to stay healthy during upstream migration. Last summer, however, river temperatures in Bristol Bay reached 76 degrees. That spells problems for the fish: When salmon can’t avoid warm water, they can sicken or die. Warm water adds stress at a time when fish are already tackling the herculean task of returning to headwater lakes and streams to spawn, making them more susceptible to diseases and speeding up their already-taxed metabolisms. Something like a heart attack can follow: Warm water holds less oxygen than cooler water, but at higher temperatures, salmon actually need more oxygen to survive. Under those conditions, their hearts can’t pump blood fast enough to support their brains and bodies.
In Bristol Bay, state biologists manage salmon by opening and closing commercial fishing to allow enough fish to reach the areas where they spawn. Each river system has a target number of adult salmon that should evade capture—an “escapement goal” that is designed to ensure the future of the population. But last summer Alaska sizzled with heat, and warm river water pressed down the Ugashik, preventing salmon from heading upstream. Along Bristol Bay, rubber raingear melted. Some fishermen fished wearing only underwear and waders. The weeks of sunny, windless weather baked the region’s lakes and rivers.
But because the fish moved all at once in a huge slug, faster than the fishermen could catch them, thousands more passed upstream than the escapement goal. Those salmon could have been netted had the run been more gradual, or if fishermen had been allowed to fish when the temperatures were high. Bursch, who houses her crew in a 100-year-old cannery building in one of the bigger operations on the river, calculated that Ugashik fishermen took a collective hit of $1 million.
Fishermen Bursch and Kosbruk are expecting plenty of sockeye to return again this year. That’s because, somewhat ironically, salmon runs in Bristol Bay have been huge in recent years: Last summer’s return of some 56.6 million fish was the fourth-largest on record, 45 percent higher than the 20-year average. Warming seas are likely the reason. With warmer-than-average ocean temperatures still well below heat thresholds for salmon, smolts have been surviving their first months at sea in greater numbers.
Although wild salmon runs have failed in most of the rest of the world, in Alaska, there’s optimism that the fish will keep returning, even as temperatures rise. “Sockeye salmon have a lot of flexibility in their lifecycle, (and) that makes them resilient to climate change,” said Daniel Schindler, an ecologist at the University of Washington who has been studying Bristol Bay salmon for more than 20 years. “We should give them the opportunity to adapt.” This includes, he explained, reducing competition at sea from millions of hatchery salmon and prohibiting industrial development—such as the proposed Pebble Mine—in salmon watersheds.
In recent years, Bursch and other Ugashik fishermen have noticed the rising river temperatures. They typically chill their fish in totes of ice or, on larger boats, with onboard refrigeration systems to get a better price per pound; salmon coming out of warmer water are warmer, and it has been taking noticeably longer to cool them. But last summer’s 10-day closure, and the conditions that caused it, came as a shock. According to Sue Mauger, a stream ecologist at Cook Inletkeeper who has been monitoring salmon streams in Alaska for nearly two decades, temperatures as high as last year’s match the projections for 2069. “We knew it was warming, but we didn’t expect to see that result that quickly,” Bursch said.
TopicsClimate Deskfishclimate changeAlaskaenvironment
In Alaska, Summer’s Getting Too Hot for the Salmon Run | WIRED
06.13.2020 08:00 AM
Photograph: Scott Steindorf/Getty Images
This story originally appeared in High Country News and is part of the Climate Desk collaboration.
Unable to wet their nets and unsure when the fishery would reopen, Ugashik fishermen bided their time at seasonal camps, looking on as jumpers pocked the water all day long. “You’re pretty much watching your income go by,” Catie Bursch, a commercial setnetter on the Ugashik, said later. As Bristol Bay fishermen gear up for this year’s salmon season—one beset by fears that Covid-19 could overwhelm this remote region as thousands of seasonal workers from across the world descend on fishing communities with scant medical resources—they must also contend with a slower-moving hazard: the warming temperatures that threaten a $1.5 billion industry and the people it supports.
Every year, millions of salmon return to the Bristol Bay watershed on their annual summer migration to the headwaters where they spawn. This 250-mile-long nook in the Bering Sea is largely undeveloped—an area the size of Iceland, riddled with lakes, streams and wetlands that provide some of the planet’s best habitat for anadromous fish.
The Ugashik is a muddy world, where fishermen slog through knee-deep muck to secure nets along the edge of the river at low tide. A single net can yield thousands of pounds of salmon, which fishermen pick by hand from small open skiffs and then deliver to buyers on tenders anchored downstream. Some of the Ugashik setnetters have fished here each summer for decades, living in plywood bunkhouses in a dozen or so camps, bathing in handmade saunas, and riding four-wheelers into Pilot Point, a village of fewer than 100 residents, where milk costs $20 per gallon.
In addition to being the region’s economic driver, salmon represent a primary food source for the residents in remote towns and villages, most of whom are Yup’ik, Dena’ina, and Alutiiq. Each summer, Mark Kosbruk, an Alutiiq setnet fisherman on the Ugashik, puts up about 200 fish—canned, smoked, dried, salted—for home use. Last summer’s closure was “nerve-wracking,” Kosbruk told me recently. Dogged by the concern that he might not get to fish at all, Kosbruk fixed everything he could around his camp, topped off all of his engines with oil, then waited.
The state stipulates that water temperature must not exceed 59 degrees Fahrenheit in order for salmon to stay healthy during upstream migration. Last summer, however, river temperatures in Bristol Bay reached 76 degrees. That spells problems for the fish: When salmon can’t avoid warm water, they can sicken or die. Warm water adds stress at a time when fish are already tackling the herculean task of returning to headwater lakes and streams to spawn, making them more susceptible to diseases and speeding up their already-taxed metabolisms. Something like a heart attack can follow: Warm water holds less oxygen than cooler water, but at higher temperatures, salmon actually need more oxygen to survive. Under those conditio
ns, their hearts can’t pump blood fast enough to support their brains and bodies.
In Bristol Bay, state biologists manage salmon by opening and closing commercial fishing to allow enough fish to reach the areas where they spawn. Each river system has a target number of adult salmon that should evade capture—an “escapement goal” that is designed to ensure the future of the population. But last summer Alaska sizzled with heat, and warm river water pressed down the Ugashik, preventing salmon from heading upstream. Along Bristol Bay, rubber raingear melted. Some fishermen fished wearing only underwear and waders. The weeks of sunny, windless weather baked the region’s lakes and rivers.
But because the fish moved all at once in a huge slug, faster than the fishermen could catch them, thousands more passed upstream than the escapement goal. Those salmon could have been netted had the run been more gradual, or if fishermen had been allowed to fish when the temperatures were high. Bursch, who houses her crew in a 100-year-old cannery building in one of the bigger operations on the river, calculated that Ugashik fishermen took a collective hit of $1 million.
Fishermen Bursch and Kosbruk are expecting plenty of sockeye to return again this year. That’s because, somewhat ironically, salmon runs in Bristol Bay have been huge in recent years: Last summer’s return of some 56.6 million fish was the fourth-largest on record, 45 percent higher than the 20-year average. Warming seas are likely the reason. With warmer-than-average ocean temperatures still well below heat thresholds for salmon, smolts have been surviving their first months at sea in greater numbers.
Although wild salmon runs have failed in most of the rest of the world, in Alaska, there’s optimism that the fish will keep returning, even as temperatures rise. “Sockeye salmon have a lot of flexibility in their lifecycle, (and) that makes them resilient to climate change,” said Daniel Schindler, an ecologist at the University of Washington who has been studying Bristol Bay salmon for more than 20 years. “We should give them the opportunity to adapt.” This includes, he explained, reducing competition at sea from millions of hatchery salmon and prohibiting industrial development—such as the proposed Pebble Mine—in salmon watersheds.
In recent years, Bursch and other Ugashik fishermen have noticed the rising river temperatures. They typically chill their fish in totes of ice or, on larger boats, with onboard refrigeration systems to get a better price per pound; salmon coming out of warmer water are warmer, and it has been taking noticeably longer to cool them. But last summer’s 10-day closure, and the conditions that caused it, came as a shock. According to Sue Mauger, a stream ecologist at Cook Inletkeeper who has been monitoring salmon streams in Alaska for nearly two decades, temperatures as high as last year’s match the projections for 2069. “We knew it was warming, but we didn’t expect to see that result that quickly,” Bursch said.
TopicsClimate Deskfishclimate changeAlaskaenvironment