It is official: El Niño has arrived, and forecasters say this one could be a heavyweight. NOAA declared an El Niño Advisory on June 11, announcing that the warm phase of the El Niño-Southern Oscillation has settled into the tropical Pacific. The agency now puts the odds of a "very strong" event at 63% for the November 2026 to January 2027 window — a tier reached only three times since 1980, most recently in 2015.
For anglers, the headline is simple: the water is changing, and the fish will move with it.
"Each one is unique with its own imprint on our weather," said Ken Graham, director of NOAA's National Weather Service. No two El Niños behave the same way, but decades of records give scientists a working map of what tends to follow. During El Niño, the trade winds that normally push warm water west across the Pacific weaken, letting that warm pool spread east toward the Americas. The knock-on effects reach the seafloor.
The clearest impact for fishers is what happens to the food chain. Strong El Niños have historically thinned out plankton in the open Pacific, and that shortage ripples upward.
"It's important because that's the base of the food web," said Andrew Leising, a research oceanographer at NOAA, speaking at the Aquarium of the Pacific. "Marine mammals and other migratory species end up being closer to shore, because they're going to where their food is."
That shift cuts both ways. The same conditions that crowd whales and sharks toward the coast can also pull tuna in tight, opening up rare inshore shots at pelagic fish. But warmer water also raises the risk of harmful algal blooms, which can shutter fisheries with little warning. Leising pointed to the aftermath of the 2014 "Blob," the marine heat wave that preceded the last big El Niño: "We had several closures of crab and shellfish fisheries due to harmful algal blooms." Market squid, one of California's most valuable catches, tend to thin out and shift north in those conditions.
The damage can run deeper than the surface. Writing in The Conversation, climate scientist Dillon Amaya noted that El Niño tends to trigger marine heat waves that reorganize entire ecosystems. Pacific cod fell 70% in the Gulf of Alaska after one such event, and Bering Sea snow crab landings dropped 84% in 2018 after a heat wave reached the bottom. Some fish, he wrote, burn energy so fast in warm water that they starve.
It is not all bad news on the calendar. A strong El Niño usually ramps up wind shear over the Atlantic, which tears apart developing storms. "Wind shear is good for us, bad for the hurricanes," said Phil Klotzbach, the hurricane forecaster at Colorado State University. NOAA's 2026 outlook leans below normal, which can mean more fishable days on the Gulf and East Coast through the fall.
The trade-off is water. NOAA oceanographer William Sweet warned that El Niño tends to stack flooding onto already-high seas. "It usually ends up being a double whammy," he said. "The first punch is decades of sea level rise, which has waters close to the brim in many coastal communities. And now with this second punch — a strong El Niño — coastal communities face more frequent, deeper and widespread high tide flooding along both the West and East Coasts."
Wildlife will signal the strain first. "California sea lions are indicator species, meaning they will be one of the first species which may show signs of domoic acid toxicity, respond to changes in their ecosystem, and signal to the public how our oceans and ecosystem are doing," said Brett Long, vice president of animal care at the Aquarium of the Pacific.
The practical takeaway for anglers is to stay flexible. Forecast models can now predict marine heat waves three to six months out, and they tend to be most accurate during El Niño years. Watch the water temperatures, expect target species to follow the food — often closer to shore — and plan around closures before they arrive.
