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In 2013, a mass of unusually warm water appeared in the Gulf of Alaska. Over the next three years, the Blob, as it became known, spread more than 3,200 kilometers, reaching down to Mexico. This freak marine heatwave, combined with a strong El Niño, drastically affected the Pacific Ocean ecosystem killing thousands of animals and changing the distribution of species along the coast.

It’s been three years since the Blob dissipated, and researchers are taking stock of its long-term impacts on fish and other wildlife.

Last month, Laurie Weitkamp, a fisheries biologist with the Northwest Fisheries Science Center, and her colleagues released a report detailing how the Blob affected species found in the northern California Current ecosystem, which runs from the Canadian border to southern Oregon. The report shows that the mass of warm water helped some and hurt others. Between 2013 and 2017, for instance, the populations of animals accustomed to warm water, such as mackerel, squid, hake, and rockfish, ballooned. Many jellyfish species also had a strong showing.

One of the strongest effects of the Blob was the explosion of California market squid along the Oregon coast. In 2018, fishers in Oregon landed more than three million kilograms of market squid, shattering the previous record of a mere 1.2 million kilograms in 2016. Meanwhile, fewer squid swam in the waters off California, their usual stronghold.

Troy Buell, the fisheries management program leader at the Oregon Department of Fish and Wildlife, says the boom was likely the result of more squid being born in Oregon waters rather than animals moving up from the Golden State. Squid fishers, however, did migrate north to cash in.

But other species have struggled in the wake of the Blob. “When fish hatch out of their eggs, they absorb their yolk sac and have to start feeding,” says Weitkamp. But if their food isn’t there, “they’re screwed.” For many young fish, their favorite food was wiped out by the heat or shifted elsewhere.

As a result, there is now a void in the populations of some species that were in their larval stages when the Blob hit its crescendo. Species that should be along the Pacific coast or returning to inland waterways simply aren’t. And that’s taking a toll on the ecosystem and on commercial fisheries.

Chinook salmon, for example, are often harvested when they are around three or four years old, meaning that the salmon that went out to sea in 2015 should have returned home this year. As a result of the Blob, says Weitkamp, the Columbia River has “the lowest spring return ever of chinook this year.” In response, Washington State has suspended summer chinook fishing.

This July, British Columbia, also suffering low returns of sockeye salmon due to the Blob, closed the recreational sockeye fishery on the Skeena River. The return of sockeye and pink salmon to the Fraser River this year is also uncertain.

Alaska, meanwhile, is a story of contrasts. Pacific cod crashed around 2017, and the shrimping industry has struggled, too. But in 2018, Bristol Bay, in southwest Alaska, saw the highest return of sockeye salmon ever recorded. “It’s so strange,” says Weitkamp. “It’s so unpredictable.”

There have been less obvious consequences of the Blob, too. Scientists believe that the availability of prey for humpback whales has changed around California. “There’s now a lack of krill, so the whales are feeding on anchovies closer to shore, which is also where there is more overlap with crab gear,” says Buell. This change in feeding habits may be contributing to a recent spike in whale entanglements.

It’s unclear how long the consequences of the Blob might last or when the next Blob might hit.