How Will El Niño Affect Your Local Fisheries

What does El Niño mean for U.S. fisheries and marine life? What can fishermen and coastal communities expect to observe and experience as this event continues and potentially intensifies? And what are scientists at NOAA Fisheries doing to track this natural phenomenon?

The El Niño-Southern Oscillation is a powerful atmospheric cycle that occurs in the Pacific Ocean along the Equator and weakens trade winds that blow from east to west. This allows warm surface water in the Pacific to slosh back east towards the Americas. It reduces the amount of cold water upwelling that usually occurs off the coast of South America. This natural phenomenon can have intense atmospheric and oceanographic effects, such as increased precipitation, flooding, and warmer ocean temperatures. These impacts vary by geographic location but are typically felt most directly by regions within the Pacific Basin.

In June 2026, NOAA forecasters announced that El Niño had formed in the tropical Pacific. As of September, they have predicted a greater than 90 percent chance of a "very strong event" during the Northern Hemisphere fall and winter 2026-27. Experts expect this event will persist through early spring 2027, with the potential for observable impacts in marine ecosystems for months or even years afterwards.

Scientists still can't predict exactly what will occur during this period. But NOAA Fisheries can draw upon historic observations and an abundance of data collected throughout previous El Niño events to suggest likely impacts across our ecosystems. Additionally, we are actively deploying tools and strategies to monitor and predict El Niño's impact on the marine environment across the United States, including:

Learn more about what you can expect from this El Niño event and what NOAA Fisheries is doing to forecast and document its impacts.

West Coast

Because El Niño occurs in the Pacific Ocean basin, the West Coast typically experiences the most direct impacts, including elevated sea levels and unusually warm ocean temperatures. Fishermen in Southern California are already catching large numbers of species such as wahoo, striped marlin, and yellowfin tuna, which are normally found off the coast of Mexico. Other warm-water species have been observed in California waters, including the first documented nesting of olive ridley sea turtles . Scientists are tracking how marine species distributions may change along the entire West Coast. Based on previous El Niño events, experts anticipate that we will likely see a variety of changes in this region , including:

More In-Depth Information About West Coast Impacts

Pacific Islands

The Pacific Islands Region is bounded by the Hawaiian Archipelago in the north, American Samoa in the south, and the Marianas Archipelago in the west. It is the largest geographical area within NOAA Fisheries' jurisdiction. We monitor marine life in all of these areas. Current forecasts suggest that this El Niño event will have a significant impact on the Pacific Islands Region as a whole, but the specific effects and degree of impact will vary by island area.

Hawai'i, American Samoa, Guam, and the Commonwealth of the Northern Mariana Islands are located outside the area of greatest predicted warming and heat stress for the next several months. However, it's likely these islands will still experience significant impacts from this El Nino event, including:

• Warming and heat stress
• Changes in predator-prey dynamics
• Changes to species distribution
• Increased hurricane activity

In American Samoa, previous El Niño events produced strong, prey-rich currents within known albacore fishing grounds. This resulted in higher albacore longline catch rates in these areas. Additionally, El Niño also shifts the western Pacific warm pool, and its associated tuna habitat, eastward, resulting in an eastward shift in offshore fishing opportunities. For Hawai'i and the Marianas, El Niño's impact on local catch rate remains less certain and depends on species, fishing method, and location.

The elevated hurricane activity associated with El Niño in the Central Pacific also may affect the chain of operations for local fisheries, especially if major fishing ports are impacted.

Protected species may be impacted by changing food availability, feeding habitat, and nesting conditions. In Hawaiʻi, research by Pacific Islands Fisheries Science Center staff links variation in young monk seal survival to ocean productivity and prey availability. This indicates that changes in food supply could affect their condition and survival.

Across the three areas, sea turtles may be affected by hotter nesting beaches or nest flooding. Excessive sand temperatures can reduce egg survival and produce more female hatchlings, while nest flooding can kill developing embryos. Changes in ocean conditions may also redistribute prey for seabirds, whales, and dolphins, potentially altering their feeding locations and reproductive success.

Prolonged warming events, like those associated with El Niño, can cause corals to lose the symbiotic algae that supply much of their energy. This results in bleaching and, if stress persists, mortality. Past El Niño-associated events caused widespread bleaching in Hawaiʻi and substantial coral losses at Swains Island in American Samoa, where impacts and recovery varied with depth. In Guam, El Niño-associated sea-level declines also exposed shallow corals to air during extreme low tides, causing tissue death and compounding earlier bleaching damage. Impacts to coral reefs during this event will depend on local temperatures, water depth and circulation, and low-tide timing. Different islands could potentially experience the greatest stress in different seasons.

Alaska

Gulf of Alaska

The intensity of El Niño's impact on the Gulf of Alaska is highly dependent on both oceanographic and atmospheric conditions. El Niño can also exacerbate pre-existing environmental conditions.

During El Niño years, the Gulf of Alaska tends to experience relatively warmer surface conditions. We can expect to see changes in plankton species compositions in the Gulf of Alaska if El Niño manifests as a warmer-than-average winter in this region. If water temperatures increase, we can expect to see plankton species with lower nutritional value dominating local ecosystems, says Dr. Bridget Ferriss, a fisheries biologist with the Alaska Fisheries Science Center .

"Some species have higher lipid, or fat, contents, which makes them more nutritious," Ferriss notes. "As water temperatures increase, less-nutritious species tend to flourish and make up a larger proportion of the zooplankton and phytoplankton communities in the Gulf of Alaska. That impacts everything that feeds on them, and can have implications for energy moving up the food web."

Alaska's groundfish , which includes species like Pacific cod and Alaska pollock , are some of the region's most commercially important species. The potential long-term impacts of El Niño on these fisheries are still somewhat unpredictable-Ferriss says it's unlikely we will see immediate changes in 2027. While the distributions of some species may shift slightly, adult groundfish tend to be comparatively more adaptable to short-term environmental changes than other species.

"If we do experience warmer waters in the region as a result of El Niño, it's possible we may see larger cohorts (fish born in the same year) of certain groundfish species following the event," Ferriss says. Sablefish , rockfish, Pacific herring and sand lance tend to do well in warmer years, she notes. However, certain species, especially cold water-associated ones like capelin and the eggs of Pacific cod, have very narrow thermal windows for survival. Either way, we would not expect to see these impacts in terms of fisheries production for at least another few years.

Research from past El Niños and marine heatwaves strongly suggests marine mammals such as harbor seals , Steller sea lions , and humpback whales are likely to be impacted should the warming effects reach the Gulf of Alaska. Scientists expect these impacts to manifest as:

• Population declines driven by changes in reproductive and survival rates
• Decreases in body condition
• Increased prevalence of disease
• Changes in diet composition
• Shifts in species distributions

Eastern Bering Sea and Aleutian Islands

Impacts of El Niño on the Eastern Bering Sea and Aleutian Islands marine ecosystems are more uncertain. If warming conditions do arrive in the Aleutian Islands, they will add to a multi-year trend of warm conditions in the region. The Eastern Bering Sea ecosystem is largely influenced by seasonal winter sea ice, the extent of which has no observed correlation to El Niño.

Warming waters across Alaska can impact marine ecosystems, whether caused by El Niño or not. These include shifts in crab and groundfish distributions, which change predator-prey interactions. Warmer waters can also lead to increased risk of harmful algal blooms . These blooms can have adverse impacts on marine mammals in the region, as was observed earlier this year with Northern fur seals on St. George Island .

Southeast, Gulf of America, and Caribbean

In the Southeast, El Niño is typically associated with reduced hurricane activity in the fall and increased precipitation in the winter.

Generally, El Niño does not strongly influence the ecology of the Gulf of America. However, excess rainfall can lead to increased freshwater discharge from river systems like the Mississippi River into estuaries in the winter and spring, decreasing their salinity. This can also negatively impact shrimp, crabs, and other commercially important species that spend their early lives in estuaries.

Increased precipitation and the consequent freshwater runoff into the Gulf's estuaries could also affect off-bottom shellfish aquaculture in Mississippi and Alabama. "El Niño-related impacts on aquaculture in the Southeast could vary depending on the intensity, timing, and farm location," says Dr. Ken Riley, science advisor for NOAA Fisheries' Office of Aquaculture .

One potential outcome is reduced pressure on oysters from Dermo disease, which is caused by the single-celled parasite Perkinsus marinus and can kill both wild and farmed oysters. It generally performs poorly under the combination of lower salinity and cooler temperatures that El Niño is expected to bring to the Gulf. At the same time, El Niño's active southern winter storm track may bring frequent fronts, rainfall, and weather conditions that could prevent growers from safely accessing or harvesting farms.

In the Caribbean and Southeast, NOAA has also been monitoring how broader ocean warming is causing heat stress on coral reefs, changes in distribution of reef-associated species, and broader ecosystem impacts that may affect fisheries, tourism, and coastal communities. El Niño-associated warming increases the risk of coral bleaching events in this region. Warmer waters may also push tropical game fish normally found further north, creating new opportunities for recreational anglers and local charter fleets.

Northeast

Historically, the Northeastern United States has not felt the impacts of El Niño as intensely as other parts of the country, because El Niño occurs in the Pacific Ocean basin. It tends to bring warmer temperatures, milder winters, and reduced hurricane risk to the Northeast. While experts anticipate the effects of this El Niño will be largely similar to what we've seen in the past, current oceanographic and atmospheric trends in the region could lead to departures from the norm.

New England's waters have warmed faster than almost anywhere else in the world in recent decades, but the region entered a period of cooling beginning in late 2024 . NOAA's Changing Ecosystems and Fisheries Initiative predicts and tracks these environmental changes using an advanced forecasting system tied to a regional ocean model called the Modular Ocean Model version 6, or MOM6.

"It's too early right now to tell what the impacts of this El Niño will be on the Northeast," says Vince Saba, a fisheries biologist with the Northeast Fisheries Science Center . "This region is already in an anomalous state relative to the last 15 years because of this current cooling event. It's hard to say whether we'll see the warmer temperatures and milder winters that we usually expect with El Niño. The MOM6 seasonal to annual forecast for the Northwest Atlantic predicts an enhanced warming of the western tropical Atlantic in early to mid-2027 due to the strong El Niño. This enhanced warming of tropical Atlantic waters will surely have impacts further north in U.S. waters, but it is unclear as to what those impacts will be."

Cooperative research , conducted in partnership with local commercial and recreational fisherman, is another crucial component of tracking these changes in fisheries. "Cooperative research is critical to filling the gaps that the Northeast bottom trawl survey does not pick up spatially or temporally," Saba says.

One example of this is NOAA's eMOLT (Environmental Monitors on Lobster Traps and Large Trawlers) Program , which has partnered with more than 100 New England fishing vessels. Through this program, fishermen attach low-cost oceanographic sensors to their fishing gear to collect data like bottom water temperature and dissolved oxygen levels in their fishing grounds. These efforts simultaneously contribute to sustainable fisheries management in the Northeast while providing fishermen with environmental data that can help them make informed decisions and support their understanding of their fishing grounds. Now, these data can also be used to track ecosystem changes we may observe in northeastern waters due to El Niño.