Saving Seafood

West Coast Waters Experiencing Another Large Marine Heatwave

March 4, 2026 — A massive marine heatwave has dominated waters off the West Coast since last summer. This marks only the third time on record that such a large section of the coastal ocean has remained so warm for so long—particularly into winter months—without it being an El Niño, NOAA scientists report. NOAA Fisheries and our partners are tracking possible heatwave impacts, which can include harmful algal blooms that can sicken marine mammals and close shellfish fisheries.

Third Time as Warm

At one point last September, the current marine heatwave rivaled the enormous 2013–2016 marine heatwave known as “The Blob” in terms of size and surface temperatures. The current heatwave has raised the temperature of waters along the West Coast roughly 3 to 4 degrees Fahrenheit above normal. On September 9, 2025, the northeast Pacific reached its highest ever average temperature of 20.6 degrees Celsius, or about 69 degrees Fahrenheit. That’s almost a half-degree warmer than ever before. Past marine heatwaves shook up marine ecosystems that drove shifts of species, die-offs, and other disruptions of ecosystems in the Northeast Pacific Ocean.

“We have forecast tools that provide some insight, but we are also watching carefully for implications on the marine ecosystem,” said Andrew Leising, a research oceanographer at NOAA Fisheries’ Southwest Fisheries Science Center. He runs the California Current Marine Heatwave Tracker. The tracker has been documenting marine heatwaves off the West Coast through NOAA data from satellites, ships, and buoys since 2019.

The North Pacific has repeatedly hit record or near-record temperatures since The Blob. Like others before it, the current marine heatwave weakened and receded from the coast in October and November 2025. Unlike others, it has since strengthened and returned. “We’re in La Niña, but water temperatures along our coast look much different,” Leising said. “The conditions are hard to reconcile. We want to be cautious in our interpretation, but at the same time this is not a situation that we have seen before.”

Heatwaves Shift Species

The current heatwave has brought news of species in unusual areas, such as tunas caught in large numbers in Alaska last fall. The Blob and other marine heatwaves have been shown to reduce the survival of salmon in the ocean, leaving fewer fish to catch and to return to rivers to spawn. “We know these marine heatwaves alter ecosystem conditions, which affects fish and other marine life,” Leising said. “We’re very interested in what the fishing fleet and others who are out on the water are seeing and are looking into new ways to collect this information. Are there species in unusual places, or what might be changing?”

In addition, the unusual warmth could begin to set the stage for a repeat of last year’s harmful algal bloom off Southern California. It hit unusually early in 2025 and killed hundreds of California sea lions, dolphins, and seabirds. Harmful algal blooms can also close fisheries, especially recreational fisheries involving shellfish that concentrate the toxins, affecting the coastal economy.

Read the full article at NOAA Fisheries

Keeping an eye on the ‘Blob’

December 1, 2025 — The marine heat wave in the Pacific Ocean, familiarly known as “the Blob,” caused major issues for Pacific fisheries and seabirds in 2014-2016, and some news agencies are reporting that the blob may be on its way north again. 

Few fishermen are alarmed, and the National Oceanic and Atmospheric Administration (NOAA) Blobtracker, last updated on Sept. 2 indicates that the blob will behave much as it has the last few years.  

But a slew of news stories on the Blob hit the internet in October. According to salmon fisherman Nick Zuanich, posting on Facebook, the articles are based on August temperatures, and nothing to get alarmed about.

“The blob is what happens when the typical fall/spring southerly storms don’t show up. Southerly storms get the Pacific current running to the north, hitting the continental shelf, bringing cooler, nutrient-rich waters to the surface, thereby cooling the North Pacific. This has happened once again, thankfully,” says Zuanich. 

Read the full article at the National Fisherman

Marine heat wave known as ‘the Blob’ returns to Pacific, but so far spares Oregon and Washington

October 17, 2025 — A massive heat wave is hitting the Pacific Ocean from Kamchatka to California.

Water temperatures several degrees above normal span thousands of miles, though they have mostly stopped short of the Pacific Northwest coast. Cool water welling up from the depths is thought to be keeping surface temperatures near the Oregon and Washington coasts closer to normal.

Beyond disrupting the ocean’s food web and fisheries, the underwater heat wave, known as “the Blob,” can alter weather on land thousands of miles away.

Since May, an ever-shifting mass of overheated water has occupied much of the northern half of the Pacific Ocean.

In early September, it covered 3 million square miles — about the size of the contiguous United States — according to the National Oceanographic and Atmospheric Administration’s “Blobtracker” program.

Read the full article at OPB

Return of The Blob: Heat wave spans Pacific Ocean

October 10, 2025 — A massive heat wave is hitting the Pacific Ocean from Kamchatka to California.

Water temperatures several degrees above normal span thousands of miles, though they have mostly stopped short of the Pacific Northwest coast. Cool water welling up from the depths is thought to be keeping surface temperatures near the Oregon and Washington coasts closer to normal.

Beyond disrupting the ocean’s food web and fisheries, the underwater heat wave, known as “The Blob,” can alter weather on land thousands of miles away.

Since May, an ever-shifting mass of overheated water has occupied much of the northern half of the Pacific Ocean.

Read the full article at KUOW

Marine heatwave ‘blob’ returns in Pacific, rivaling past events in size and impact

September 26, 2025 — In 2013, scientists noticed a block of unusually warm water detected in the Pacific Ocean between the Gulf of Alaska and the Coast of Southern California. This was recognized by meteorologists as a basin-scale marine heatwave (MHW), often referred to as “the blob”. This water mass hung around from 2013-2016 before re-emerging again in July of 2019 (known as Blob 2.0) and lasting 20 months.

In May 2025, the blob reappeared.

Rachel Hager, a spokesperson for NOAA Fisheries, said this new MHW has grown “approximately the same size as the contiguous U.S.” She added it now ranks among the top three largest MHWs ever recorded in the northeast Pacific Ocean since monitoring began in 1982.

Read the full article at KATU 2

The world’s longest marine heat wave upended ocean life across the Pacific

August 8, 2025 — More than a decade since the start of the longest ocean warming event ever recorded, scientists are still working to understand the extent of its impacts. This unprecedented heat wave, nicknamed “The Blob,” stretched thousands of kilometres over North America’s western coastal waters, affecting everything from the smallest plankton to the largest marine mammals.

Between 2014 and 2016, when this heat wave occurred, water temperatures soared between two to six degrees C above average.

One would be forgiven for thinking this is no big deal. After all, temperatures fluctuate more than this on land most days. But not so in the ocean, where temperatures are normally much more stable because of the enormous amount of energy it takes to change them.

Although the duration of this multi-year warming event made it the first of its kind, it offers a glimpse into a future with climate change, where heat waves like this will be more frequent.

Read the full article at the Conversation

A Warning From a California Marine Heat Wave

December 2, 2024 — They call it “the Blob.”

A decade ago, sea surface temperatures in the Pacific shot up to 11 degrees Fahrenheit hotter than normal. A high pressure system parked over the ocean, and winds that churn cold, nutrient-rich water from the depths to the surface died down. Stagnant, warm water spread across the Northeast Pacific, in a marine heat wave that lasted for three years.

Under the surface, the food web broke down and ecosystems convulsed, at first unseen to humans on shore. But soon, clues washed up.

Dead Cassin’s auklets — small, dark gray seabirds — piled up on West Coast beaches. The auklets were followed by common murres, a slightly bigger black-and-white seabird. The carcasses were knee-deep in places, impossible to miss.

Researchers are still untangling the threads of what happened, and they caution against drawing universal conclusions from a single regional event. But the Blob fundamentally changed many scientists’ understanding of what climate change could do to life in the ocean; 10 years later, the disaster is one of our richest sources of information on what happens to marine life as the temperature rises.

And it is more relevant than ever. Last year, multiple “super-marine heat waves” blanketed parts of the ocean. Averaged together, global sea surface temperatures broke records, often by wide margins, for months in 2023 and 2024. As the climate warms, scientists expect extreme marine heat waves to become more frequent.

The Blob “was a window into what we might see in the future,” said Julia Parrish, a marine ecologist at the University of Washington who runs the Coastal Observation and Seabird Survey Team, a network of volunteers who survey beaches from Northern California to Alaska.

In a study published last year, Dr. Parrish and her colleagues estimate that the Blob eventually killed millions of seabirds, in waves of starvation.

Read the full story at the New York Times

Where Will the Whales Be? Ask the Climate Model.

December 5, 2023 — The opening of California’s commercial crab season, which normally starts in November, is delayed once again to protect humpback whales foraging for krill and anchovies along the coast.

This region of the Pacific has been under the grip of a marine heat wave since May. “The Blob,” as this mass of warm water has become known, is squeezing cooler water preferred by whales and their prey close to shore, where fishermen set their traps.

This crowding can lead to literal tangles between whales and fishing equipment, endangering the animals’ lives and requiring grueling rescue missions.

In a new study, scientists say they can now use global temperature models, commonly used in climate science, to predict up to a year in advance when hot ocean temperatures raise the risk of whale entanglements. This lead time could allow state regulators, fishermen, and other businesses that depend on the fishery — as well as Californians hoping for a Dungeness crab holiday meal — to plan ahead for potential fishing restrictions.

“It really just helps give a lot more information and reduce some of that uncertainty about the future,” said Steph Brodie, lead author of the study published Tuesday in the journal Nature Communications. Dr. Brodie is currently a research scientist at Australia’s national science agency, but conducted this research while working at the University of California Santa Cruz and the National Oceanographic and Atmospheric Administration.

Read the full story at the New York Times

New global forecasts of marine heatwaves foretell ecological and economic impacts

April 22, 2022 — Researchers have developed global forecasts that can provide up to a year’s notice of marine heatwaves, sudden and pronounced increases in ocean temperatures that can dramatically affect ocean ecosystems.

The forecasts described in the journal Nature could help fishing fleets, ocean managers, and coastal communities anticipate the effects of marine heatwaves. One such heatwave, known as “the Blob,” emerged about 2013 in the northeast Pacific Ocean and persisted through 2016. It led to shifting fish stocks, harmful algal blooms, entanglements of endangered humpback whales, and thousands of starving sea lion pups washing up on beaches.

“We have seen marine heatwaves cause sudden and pronounced changes in ocean ecosystems around the world, and forecasts can help us anticipate what may be coming,” said lead author Michael Jacox, a research scientist at NOAA Fisheries’ Southwest Fisheries Science Center in Monterey, California, and NOAA’s Physical Sciences Laboratory in Boulder, Colorado.

Marine heatwave forecasts will be available online through NOAA’s Physical Sciences Laboratory. The researchers called the forecasts a “key advance toward improved climate adaptation and resilience for marine-dependent communities around the globe.”

Read the full story at ScienceDaily

Return of ‘the Blob’ could intensify climate change impacts on Northeast Pacific fisheries

April 22, 2020 — A large marine heatwave would double the rate of the climate change impacts on fisheries species in the northeast Pacific by 2050, says a recently released study by researchers from the University of British Columbia and University of Bern.

In 2013, a large marine heatwave, nicknamed the ‘Blob’, occurred in the northeast Pacific Ocean. From the coast of Alaska to Baja California, the Blob had a significant impact on the  and fisheries in this region; an impact that lasted for several years.

The new study, released in the journal Scientific Reports, combined the latest , ocean and fish modelling approaches to quantify the future impacts of marine heatwaves like the Blob on fish stocks along the west coast of Canada and USA. The resulting models showed that future ‘blobs’ would exacerbate climate change impacts on these important fish stocks, causing them to decrease in biomass and generating shifts in their distribution, which, in turn, would impact the fisheries sectors in this region.

Read the full story at PHYS.org