Scientists are increasingly worried about the possibility of more die-offs and other adverse effects on marine mammals and seabirds if the suspected cause, a huge anomaly of warm water in the northeast Pacific Ocean, persists into this summer.
KTOO’s Matt Miller has more in the first of a two-part series.
Biologists and ecologists reported on their latest observations at a two-day workshop held in January on the University of Washington campus. The conference was a follow-up to a similar gathering held last May near San Diego that primarily featured oceanographers, marine researchers and climatologists.
“I just wanted to point out that ‘14 and ‘15 have been two of the warmest years on record for temperatures in coastal Alaska,” said Russell Hopcroft of the University of Alaska Fairbanks’ School of Fisheries and Ocean Sciences. “This is fed back through the state and may even be responsible for increased wildfires in the past year.”
Hopcroft commentted on the possible environmental and economic impacts of the warm water anomaly that has lingered in the northeast Pacific Ocean for the last two years.
One leading theory being considered by marine researchers and biologists centers on the warm water mass’s apparent ability to deprive fish, seabirds and seaweed of their normal food sources. Water temperatures down to a depth of 300 feet have ranged from 2 to 8 degrees Fahrenheit above normal. The layer of warm water on top of cold water can create stratification of the water column in which plankton and nitrate nutrients are prevented from rising to the surface.
“Certainly the salmon returning this year — the pinks that only go out for two years , so they were out in 2014 and 2015 — were coming back about half weight,” said Richard Dewey of Ocean Networks Canada and the University of Victoria. “The herring are half weight. And so, the northeast Pacific has been pretty malnourished. I think the nourishment comes from the wind mixing of nutrients up into the Gulf of Alaska.”
Warm water copepods are a form of plankton which have fewer lipids or less fat content than cold water species. Bill Peterson is an oceanographer at National Oceanic and Atmospheric Administration’s Newport Research Station in Oregon. For the first time in his over thirty year career, Peterson says eleven new species of warm water copepods just appeared on West Coast.
“The copepods tell us that water came from a long ways away,” Peterson said. “Where it came from, I don’t know. But it’s an issue we have to solve, I think. This water just didn’t sit there and warm up. It came from someplace different.”
As an example, an alarming spike in sea lion strandings along the California coast over the last two years may be caused, in part, by the incoming mass of warm water. Upwelling of ocean water near the coast would normally stir up cold water copepods that may be a major food source for sardines and anchovies. That upwelling was reduced dramatically or completely overwhelmed when the warm water mass moved right up to the shoreline. Sardine and anchovy populations relocated northward to find food, and sea lions may have been deprived of a major food source for themselves and their pups.
It’s possible such breakdowns in the marine food web were also the cause of the extraordinary number of whale strandings, as many as 30 were reported along Alaska’s coastline last year. There’s also the near-complete collapse of the Pollock hatchling population around Kodiak Island, and this winter’s die-off of over 22-thousand common murres in Alaska.
Scientists are also curious about whether arrival of The Blob was responsible for absence of nitrate nutrients that led to jellyfish blooms and devastation of kelp beds along the West Coast.
There was also an observed a shift in the diatom population, outbreaks of paralytic shellfish poisoning, and crashes in the populations of Cassin’s auklets, Heermann’s gulls and other seabirds .
Eric Bjorkstedt, fisheries researcher at California’s Humboldt State University and the Southwest Fisheries Science Center, says they’re seeing more algae blooms which spread toxins like demoic acid that pervade the entire food web. Bjorkstedt says one of his colleagues described it as…
“’Wicked cauldron of nastiness.’ That might explain why crab are so affected,” said Bjorkstedt. “This is a big deal, especially in our little neck of the woods where crab is a huge part of the economy. The fact that it’s still closed because of demoic acid is a big problem.”
Steve Fradkin, a coastal ecologist at Olympic National Park in Washington state, says they’re investigating a potential link to a disease that has infected over 22 species of sea stars up and down the West Coast.
“The incidence of sea star wasting disease appears to be related to warm water temperature anomalies,” Fradkin said. “So, whenever the temperature anomaly is 1 and a half degrees or greater, we see a spike in sea star wasting disease.”
Some species may only be able to tolerate such a dramatic temperature change for only a short period of time. For example, reports of California sea lion and Northern and Guadalupe fur seal strandings noticeably jumped in 2014, and then skyrocketed to unprecedented levels in 2015. After hearing the presentation, Art Miller, research oceanographer at Scripps Institute of Oceanography in La Jolla, California, had this observation:
“Warm anomalies have persisted for more than two years, and it looks like the real killer was the second year,” Miller said. “So, perhaps animals could be resilient to one bad year. But if you start stacking them up, things could start to get precipitously worse.”
Of course, correlation does not necessarily mean causation. Whale and seabird die-offs, for example, have not yet been conclusively linked to the lack of forage. Scientists want to do more research before pinning any blame on The Blob, or even going as far as suggesting that the phenomenon is a product of climate change.
About 100 researchers specializing in salmon ecology will participate in a three-day conference in Juneau in late March. Discussions will center on how the recent warm water conditions may affect this season’s salmon production from Alaska to California.
Coming up in part two, will The Blob survive into this summer and what kind of an affect will El Niño have on it.
Matt Miller is a reporter at KTOO in Juneau.
