Scientists are watching for how a warmer North Pacific Ocean could affect weather and climate this year. There could also be significant impacts to marine life, including species that form the basis for Alaska’s commercial fisheries.
A conference at California’s Scripps Institution of Oceanography earlier this month featured scientists in fields ranging from avian biology to Arctic climatology. They tried to determine the potential impacts of a giant mass of warm, ocean water that currently stretches from the Gulf of Alaska down to Baja California.
Temperatures have increased more than two degrees Celsius since the fall of 2013.
“I know. It doesn’t seem like very much,” says Molly McCammon of the Alaska Ocean Observing System, an observing and data gathering organization based in Anchorage. “But for species that live in the ocean, it’s a big deal. One degree C is a big deal. So, yes, it can have a big impact.”
McCammon helped organize the Alaska contingent that participated in theCalifornia conference on the warm water anomaly that’s been nicknamed “The Blob”. The mass of warm ocean water may be a factor in Alaska’s recent mild winters, dry conditions along the West Coast, and extreme cold conditions in the Great Lakes region last winter. It’s not the same as El Niño which has its origins in the equatorial ocean, and it’s not clear if The Blob is related to Pacific Decadal Oscillation, a longer-term cycle of ocean climate variability. The Blob’s formation may have been generated by a lingering high pressure system over the Northeast Pacific that diverted winds and passing storm systems. As a result, the ocean surface did not have the chance to cool off as usual.
“I think the consensus was that, yes, this is an unusual warming event. It’s above and beyond just the warming that’s happening as a result of global warming,” McCammon says. “There also seems to be an El Niño forming right now as well. They think that’s separate, but it could be merging, exacerbating this warming event. So, there‘s a lot of unknowns.”
The relationship between the ocean and atmosphere is complex, and interactions are rarely linear or sequential. Ocean surface temperature, surface and subsurface currents, atmospheric pressure, winds, temperature, precipitation, and geography may all be linked in some way. How each condition influences another could vary significantly.
“That’s actually what we’re trying to figure out at the moment: What or how (are) things might be linked to The Blob,” says Peter Bieniek, a post-doctoral fellow at the University of Alaska Fairbanks’ International Arctic Research Center. He was one of the Alaska scientists invited to attend the SIO conference.
“Normally, there are linkages to what goes on in the North Pacific, and especially the equatorial Pacific,” Bieniek says. “Sea surface temperatures, like if there’s an El Niño going on in the equatorial Pacific, then we’ll tend to get, for instance, warmer-than-normal winters in Alaska.”
Bieniek expects the higher ocean temperatures will persist for the rest of the year. The longer view, however, is difficult to predict.
Scientists believe the layer of warm surface water extends to a depth of a hundred meters. The boundary acts as a barrier and can hinder up-and-down movement of phytoplankton through the water column. The tiny, light-sensitive marine organisms form the base of the ocean food chain.
Jamal Moss, fisheries research biologist for the National Oceanic and Atmospheric Administration in Auke Bay, says the prognosis is good so far for juvenile Alaska salmon now heading out to the open ocean. This year’s juvenile pinks, for example, are the biggest ever and have the largest lipid or fat reserves.
“So, big fish that have lots of energy tend to survive better,” Moss says. “Right now, all signs are point to good conditions for at least the Alaska stocks.”
Moss, another Alaska scientist to attend the conference, specializes in juvenile salmon and juvenile marine fish ecology.
“This might be a boon for fish,” Moss says. “It might actually help them.”
“At least in the short term because it appears that the zooplankton that juvenile fish are eating is abundant, as well as high in energy and fat,” Moss says. “Even though there are a whole new suite of predators – host of predators – that are in these waters potentially preying upon them as well, it seems like they’re going to do well.”
Unusual marine sightings in high latitudes include blue and thresher sharks, pomfret, and sunfish. Those are species that usually congregate in warmer waters.
Moss says scientists have also detected an increase in juvenile sablefish or black cod offshore of Alaska. But they don’t know yet whether it’s related to the warm water event or if it’s a coincidence.
As for the West Coast, Moss says it may be a mixed-bag of conditions for those species already in warmer water.
McCammon says scientists are already planning summer research to find out how and why the warm water mass stretched out along the West Coast and determine any potential impacts on species. A follow-up conference to compare notes is tentatively planned for late fall.