Ocean investigators set their sights on Pacific Ocean ‘blob’
A huge swath of unusually warm water that has drawn tropical fish and turtles to the normally cool West Coast over the past year has grown to the biggest and longest-lasting ocean temperature anomaly on record, researchers now say, profoundly affecting climate and marine life from Baja California to Alaska.
Researchers remain uncertain what caused the mass of warm seawater they simply call “the blob,” or what it’ll mean long term for the West Coast climate. But they agree it’s imperative to better understand its impact, as it may be linked to everything from California’s drought to record numbers of marine mammals washing up on Northern California shores.
The blob — that’s the technical term — first appeared in late 2013 as a smudge of warm water near Alaska. It then expanded southeast and merged with warm waters farther south, growing into an anomaly that extended from the Aleutian Islands to Baja California and stretched hundreds of miles west toward Hawaii.
“Just the enormous magnitude of this anomaly is what’s incredible,” said Art Miller, an oceanographer at the Scripps Institute of Oceanography in La Jolla. He was among nearly 100 scientists from Canada, the U.S. and Mexico who gathered recently at Scripps for the first time to share research about the warm-water mass.
The warmest ocean temperatures in the blob now are around 5 degrees Fahrenheit above average.A huge swath of unusually warm water that has drawn tropical fish and turtles to the normally cool West Coast over the past year has grown to the biggest and longest-lasting ocean temperature anomaly on record, researchers now say, profoundly affecting climate and marine life from Baja California to Alaska.
Researchers remain uncertain what caused the mass of warm seawater they simply call “the blob,” or what it’ll mean long term for the West Coast climate. But they agree it’s imperative to better understand its impact, as it may be linked to everything from California’s drought to record numbers of marine mammals washing up on Northern California shores.
The blob — that’s the technical term — first appeared in late 2013 as a smudge of warm water near Alaska. It then expanded southeast and merged with warm waters farther south, growing into an anomaly that extended from the Aleutian Islands to Baja California and stretched hundreds of miles west toward Hawaii.
“Just the enormous magnitude of this anomaly is what’s incredible,” said Art Miller, an oceanographer at the Scripps Institute of Oceanography in La Jolla. He was among nearly 100 scientists from Canada, the U.S. and Mexico who gathered recently at Scripps for the first time to share research about the warm-water mass.
The warmest ocean temperatures in the blob now are around 5 degrees Fahrenheit above average.
“They’re just so far off the mean that they’re shocking,” Miller said.
The blob continues to evolve. In the last month, seasonal upwelling of cooler water in Northern California has split it into two separate masses once again. And 2015 is shaping up to be an El Niño year, marked by unseasonably warm waters off the coast of South America. What researchers don’t know is if El Niño will exacerbate or neutralize the blob.
Researchers agree that unusually slack winds are to blame for the warming ocean off the West Coast, though they don’t know what drove the drop in wind. Stronger winds typically cause deep, cooler water to rise to the surface.
“If you don’t blow the wind as much, you don’t stir the ocean as much,” Miller said. The same mechanism, he said, also may be preventing rainfall from reaching California.
In August, a temperature sensor in Monterey Bay picked up its highest temperature reading ever recorded, said Francisco Chavez, a physical oceanographer at the Monterey Bay Aquarium Research Institute. On land, 2014 was the hottest year on record in California and temperatures remained higher than average until spring of this year.
Less ocean stirring also reduces upwelling of nutrient-rich deep water to the surface, which researchers think is directly related to die-offs in some marine mammals and declines in sardine fisheries. The dearth of nutrients cascades up the food chain through the ecosystem, resulting in less phytoplankton and hungrier sea lions and seals.
A California sea lion pup recovers at The Marine Mammal Center. Researchers say the phenomenon of the so-called ‘ocean blob’ of unusually warm Pacific Ocean water is causing a decrease in the food available to the pups’ mothers, and increasingly, they are abandoning their offspring because they can’t feed them. Credit Pat Wilson © The Marine Mammal Center
Sea lion pup Percevero (center) is one of more than 200 patients at The Marine Mammal Center in Sausalito, California. Researchers say the phenomenon of the so-called ‘ocean blob’ of unusually warm Pacific Ocean water is causing a decrease in the food available to the pups’ mothers, and increasingly, they are abandoning their offspring because they can’t feed them. Credit © The Marine Mammal Center
Volunteers from The Marine Mammal Center release California sea lions at Chimney Rock in Point Reyes National Seashore in 2014. Researchers say the phenomenon of the so-called ‘ocean blob’ of unusually warm Pacific Ocean water is causing a decrease in the food available to the pups’ mothers, and increasingly, they are abandoning their offspring because they can’t feed them.Credit Conner Jay © The Marine Mammal Center
In 2014, the Marine Mammal Center in Sausalito saw more stranded California sea lions and northern elephant seals than average, according to center marine scientist Tenaya Norris, and record numbers of dying Guadalupe fur seals have washed up so far in 2015. Norris said that only about 60 percent of the mammals they rescue recover enough to be returned to the wild.
This year, sea lion pups in particular are stranding much earlier than usual, a sign that their mothers are abandoning them — an alarming indication that there’s just not enough food in the water.
“It’s a failure on the mothers’ part to adequately provision the pups,” Norris said. “They’ve been successfully foraging for years, so they should be able to find food if it’s out there.”
Paradoxically, Chavez said, 2014 in Monterey Bay was a “bonanza” for many species of birds, dolphins and whales. He hypothesized that nutrient upwelling didn’t disappear; it just shifted into cooler water closer to the coast, condensing an ecosystem that typically stretches tens of miles to only a few miles offshore. It’s unclear, however, whether the warm-water blob has played a role in the unusual number of dead whales — a dozen so far this year — that have washed ashore along Northern California beaches.
With still so many unknowns, the researchers in La Jolla agreed to meet again this coming fall. Until then, they all have homework: run climate models and dig deeper into data for patterns in weather, ocean chemistry and marine life.
“I don’t think that we found the smoking gun at the meeting,” Chavez said.
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