SEATTLE The Pacific Northwest’s orca and salmon history are intertwined. In a wide network of coevolved species and habitats, their paths intersect.
Salmon are having a hard time surviving. There hasn’t been any improvement in years for the families of the endangered southern resident orcas, which number only 73. This winter, mother orca Tahlequah carried her dead offspring, which lived for barely a week or so, bringing their predicament to the attention of the public once again.
In 2018, she carried another young calf for 17 days and more than 1,000 miles, but it lived for barely a half hour. It was terrible for a population that needed to replenish because both of the perished calves were female.
A sobering lesson about climate change can be learned from the network of factors affecting orcas, particularly the scarcity of salmon. It destroys the delicate balance of life that is essential to the natural world and what makes the Northwest so unique.
Widespread decreases in wild Chinook salmon have harmed fisheries, ecosystems, and tribal traditions that rely on the fish, particularly those in the south. Although they consume other fish, they have a preference for Chinook salmon, which are the largest and fattest in the ocean.
More of the runs that orcas rely on to grow so they may obtain enough food is essential to their existence. One of the main risks to their existence is the absence of consistently available, high-quality food.
Which salmon are most in pain?
The Columbia and Snake rivers provide fish for all three of the southern resident pods, or families. Because of their size and high fat content, Snake River spring/summer Chinook are especially valuable as food during a lean season.
Overfishing and movement impediments, such as dams, water diversions for irrigation, salmon farms, and hatcheries, have contributed to declines in wild Snake River spring/summer Chinook during the past century. The species has been steadily declining toward extinction since it was placed on the federal endangered list in 1992.
According to new research, climate change will negatively impact salmon in both their freshwater and marine life phases. Throughout the state, salmon are expected to die in streams. Because of summer droughts and scouring winter floods brought on by warming temperatures, salmon populations in the interior Columbia Basin are facing the greatest percentage loss of snow-dominated habitat.
In a 2021 publication, scientists predicted that rising ocean surface temperatures would also be a major threat to salmon, upending predator communities and ocean food webs.
What does Tahlequah have to say?
Scientists are convinced of this: even the Columbia Basin’s most fertile Chinook spawning grounds are dying due to climate change, endangering the southern resident orcas’ source of food. Warming sea surface temperatures and streams are posing an unprecedented threat to the Chinook, which orcas need on for existence.
Even the biggest spring/summer Chinook populations in the Salmon River watershed now will have plummeted to near-extinction levels by 2060, with fewer than 50 adult fish returning to their spawning grounds, the scientists discovered when they studied the effects of climate change on the salmon life cycle.
The scientists came to the conclusion that most populations will go extinct this century due to negative consequences caused by rising sea surface temperatures.
Salmon are adaptation experts. However, the scientists anticipated that they would not be able to withstand the deadly effects of rising sea surface temperatures long enough to avoid extinction in a warming world, even if they ran out to sea earlier or shifted their run time back to the river by several days.
Which salmon have shown some signs of improvement?
The good news is that salmon are reacting to significant human-made modifications for wild salmon recovery.
Steelhead, coho, and Chinook are returning to the Elwha, where habitat improvement is ongoing and two dams were removed to restore the river’s renowned salmon runs.
Even after navigating nine dams to reach spawning streams in British Columbia, improved water management on the Upper Columbia has propelled sockeye to record runs in recent years, delighting sport anglers and delivering valuable food home to Upper Columbia communities. Tribal communities of the Okanagan Nation Alliance initiated the breakthrough by inviting Canadian fisheries officials to collaborate with them and dam managers to support the operation.
In the meantime, the Nez Perce Tribe, working with other partners, has restored the Snake River’s fall Chinook run from almost extinct to the most prosperous Chinook run on the river, which benefits both commercial and sport fishermen as well as tribe fishermen.
Additionally, chum populations increased last fall from Hood Canal to the eastern coast of Vancouver Island, returning home in runs larger than those observed in decades. After decades of habitat restoration, there is a chum boom. According to a recent study by independent researcher Alexandra Morton, removing the majority of Atlantic salmon fish farms from a vital migratory corridor east of Vancouver Island significantly decreased the number of diseases, such as sea lice, that the young salmon encounter.
The 2024 chum runs kaboomed from Alert Bay in the Broughton Archipelago all the way to Puget Sound three years after the fish pens were released, Morton said, with adult returns in this area rising 10 to 20 times their typical numbers in a single generation.
The general sentiment is one of great respect for these fish; according to Morton, because the chum were performing so poorly, it was thought their time was done. However, they demonstrated incredible tenacity when we provided them with what they needed; it was astonishing.
The orcas returned when the fish did. Morton listened to the sounds of the northern resident orcas, which prefer the southern residents and mostly eat salmon, swimming past underwater microphones week after week during the chum season last fall. Her home was filled with the sound of their cries. Last fall, the southern inhabitants likewise spent day after day pursuing chum in the waters of central Puget Sound.
What is the future of climate change?
Brian Burke, a supervising biologist at the Northwest Fisheries Science Center in Seattle, speculated that there might be an ecological surprise. It is unknown what the ocean will look like in the future. What changes will those dynamics bring about? Burke stated.
However, he pointed out that there is no simple solution to reverse the decreases in marine life, and that there is no magic bullet to restore salmon runs in the Snake River Basin, not even the removal of dams.
Restoring Columbia Basin salmon will necessitate several solutions at every stage of their lives, including the removal of the Lower Snake River dam, according to a September 2022 NOAA assessment. In the meantime, the people in the south are hungry.
Today’s runs only 10% of the 1.5 million Snake River spring/summer Chinook that were once produced annually under ideal conditions. According to Rick Williams, a fish biologist from Eagle River, Idaho, and co-author of the book Managed Extinction, the fall of wild salmon in the Pacific Northwest is comparable to walking to the grocery store and finding no food.
“It is even more critical to improve the freshwater habitat because of the poor ocean conditions,” Williams said.
Controlling and managing the ocean will be extremely difficult, but on the plus side, it means that we must do everything we can in freshwater ecosystems, Williams added. But he continued, people may rely on nature. Salmon species in several Northwest rivers have demonstrated that they will recover if given the chance.
According to Williams, if we give the fish a chance, they can return.
— Tribune News Service’s Lynda V. Mapes
