Something unusual and alarming is happening in the Pacific Ocean off the California coast. Stretching from the waters off Washington state all the way down to the Baja California Peninsula, a massive marine heat wave has taken hold — and it shows no signs of retreating. Scientists are watching with growing concern, not just for the marine life already dying along California’s beaches, but for what the warming ocean means for the state’s summer ahead.
Over the past several months, an intense marine heat wave has developed in the Pacific from Washington to Baja Mexico, with a particularly extreme hot spot between the Bay Area and San Diego. Ocean temperatures have spiked to as much as 7 degrees hotter than average, with many places breaking records for this time of year. The heat wave is already causing starving birds to wash ashore and could increase the risk of thunderstorms and dry lightning that could worsen the wildfire season, scientists say.
A Century of Ocean Records, Broken Week After Week
The numbers coming out of San Diego are striking. Since January 1, there have been 36 days when sea surface temperatures at Scripps Pier in La Jolla set records for the hottest water temperature ever recorded on that date — records that stretch back to 1916.
On March 20, the ocean at La Jolla reached 71 degrees Fahrenheit — the hottest temperature ever recorded there in March, and a level normally seen in August. “It’s extreme,” said Melissa Carter, a Scripps Institution of Oceanography oceanographer. “We have had heat waves in the past. But this is a record event for the duration and the intensity.”
The heat is not limited to San Diego. Ocean temperature records have also been broken on 31 days this year off Newport Beach, 38 days off Santa Barbara, 22 days at Pacific Grove near Monterey, 9 days at the Farallon Islands off San Francisco, and 14 days at Trinidad in Humboldt County — a pattern of warmth running the length of the California coast from the Oregon border to the Mexican border.
Seabirds Are Starving
The most visible consequence of the warming ocean is washing up on California’s beaches. Tammy Russell, a marine ornithologist at the Scripps Institution of Oceanography, said seabirds in particular are being impacted. “We have been seeing an increase in the number of seabirds coming into rehabilitation facilities and washing up dead on the beaches across southern and central California for a few months now. Most of the birds are emaciated and have tested negative for HPAI — avian flu — therefore, we have concluded that the primary cause of this mortality event is due to starvation.”
Since the start of 2026, SeaWorld San Diego has rescued over 100 seabirds, primarily Brandt’s cormorants, common murres, and California brown pelicans. Rescue calls began increasing at the end of February 2026. On April 16, SeaWorld released five birds and two sea lions that had been nursed back to health.
Biologists are also reporting increased numbers of dead and emaciated seabirds on beaches from Monterey Bay to the Mexican border. The birds are not diseased. They are simply unable to find food.
The mechanism is straightforward but difficult to reverse. Warmer sea surface temperatures and reduced ocean mixing impact fish reproduction, geographic ranges, migration patterns, and food availability. During marine heat waves, species such as hammerhead sharks, bluefin tuna, and pelagic red crabs have been observed traveling further north as their warm water habitat expands — while baitfish species that serve as food sources for seabirds and sea lions shift their behavior unpredictably.
Seabirds that dive for fish near the surface are finding their prey has moved beyond reach. As Russell noted, fish that have moved deeper into cooler water are inaccessible to birds that can only dive to about six feet. The birds, she said, are the canary in the coal mine — visible early indicators of disruption that will ripple through the broader marine food web in the months ahead.
Echoes of the Blob
This is not the first time California has faced an event like this, and the precedent is not reassuring. In 2014 and 2015, a similar anomaly — nicknamed “The Blob” by researchers — caused catastrophic disruption to the Pacific food chain. Seabird die-offs occurred by the thousands, sea lion pups starved on California beaches, crab and salmon fisheries were devastated, and the economic damage to California’s fishing industry reached into the hundreds of millions of dollars.
Nick Bond, the scientist who coined the term “The Blob” in 2014 and is now a Washington state climatologist emeritus, said the current event bears serious comparison. “It’s definitely a major one in the size and the magnitude of the temperature anomalies,” he said. “Get used to it. The oceans are warming. These events, unfortunately, are going to come along more often. And this one, I think, is going to have legs.”
Dr. Cara Field, staff veterinarian at the Marine Mammal Center in Sausalito — which treated 1,800 distressed seals and sea lions during the 2015 event, triple its normal caseload — said the current situation is drawing clear parallels. “The pattern is not exactly the same, but the water temperatures and what is happening in the ocean is very reminiscent of that previous event, which was so devastating,” she said. “We’re keeping a really close eye on it. I think we should expect this is going to be a bad year and be ready for it.”
The Wildfire Connection
For Californians, the consequences of the marine heat wave extend far beyond the coastline. Scientists say the heat wave, which appears to be related to changes in wind patterns that limit the extent to which cold water in the deeper depths can move to the surface, and the intense high-pressure system that caused record hot and dry temperatures over the land in March, could bring hotter, more humid temperatures to California this summer. Also possible is an increased risk of thunderstorms and dry lightning that could worsen the wildfire season.
The connection between ocean heat and land conditions is well established. The same atmospheric high-pressure systems that suppress normal ocean circulation — allowing surface waters to heat beyond seasonal norms — also reduce onshore winds, cut cloud cover over coastal areas, and push warm, dry air inland. The result is a drier, hotter land surface that is more susceptible to ignition, particularly in a state that has already experienced some of the most destructive wildfire seasons in recorded history.
Researchers also warn that tropical cyclone activity along the California coast is elevated during years of abnormal Pacific warming. A 2023 tropical storm, the remnants of Hurricane Hilary, caused widespread flooding and closed Death Valley National Park for two months — the kind of event that was once considered a statistical rarity along California’s coast.
What Comes Next
The Scripps Institution of Oceanography has published guidance noting that during and following the 2014–2016 marine heat wave, northern anchovy and Pacific sardine populations fluctuated dramatically. These baitfish species serve as a food source for the larger fish that support California’s commercial fishing industry, as well as for seabirds and sea lions — meaning the disruption now visible on beaches could compound significantly if the heat wave persists into late summer.
Scientists at Scripps are using robotic ocean-going vehicles to investigate water temperatures below the surface. They have found that the unusually warm waters extend to significant depths — conditions comparable to those seen during a major El Niño event. Whether the heat wave moderates, holds steady, or intensifies through summer remains the critical question for California’s coastal ecology, its fishing economy, and its wildfire outlook.
What the data already confirms is that the Pacific off California is running hotter than at any point in recorded history — and the consequences are not waiting for the summer season to arrive.
