On Friday, the crew of the Bell Shimada, a 208-foot research vessel operated by the National Oceanic and Atmospheric Administration, will cast off from its home port in Newport on the central Oregon coast.

The 10-day voyage, which will take the ship 200 miles west of the coast, won’t be that different from the biweekly trips researchers have been taking for years. Biologists, ecologists and other scientists will take measurements of salinity, oxygen concentrations and water temperature. But the larger context surrounding Friday’s excursion is different from trips past.

Earlier this month, the feds announced there was trouble brewing in the Pacific: a mass of warm water was building off the west coast, reminiscent of another event nicknamed “The Blob,” which caused havoc for wildlife and fishermen just a few years ago. Experts caution that the current marine heatwave is still in its infancy and could dissipate today, tomorrow or next week. Still, given the cascading effects of the last event, where every level of the biosphere — from microscopic plankton to apex predators — saw negative impacts, the warm temperatures have the attention of researchers up and down the west coast.

“This marine heatwave took shape in June, persisted, and has grown in size,” said Chris Harvey, a research biologist at the Northwest Fishery Science Center. Harvey noted that the heatwave was currently the second largest he’s seen since satellite records began in the early ’80s, encompassing an area of the ocean more than three times the size of Alaska. “It’s still fairly young, about four months, but temps are three or more degrees Celsius above what they should be, and that’s quite a bit.”

A problem of wind, or lack thereof

Under normal circumstances, strong winds whip across the surface of the northern Pacific, pulling cold water from the depths and mixing it with warmer surface waters. The wind also dissipates some heat from the surface through evaporation.

But a ridge of low pressure set up over the northeastern Pacific in mid-summer and the winds died down. The warm water on the surface sat there, warming further.

So far, experts say, the elevated temperatures have stayed close to the surface, but the event is showing troubling similarities to The Blob of 2014 and 2015.

Heat maps show the difference in ocean temperatures in the north Pacific between 2015, left, and 2019, right. Courtesy/NOAA

One of the first signs of trouble in the early stages of the The Blob was a shift in the zooplankton, tiny crustaceans that form the base of the marine food web, said Nate Mantua, a research scientist with NOAA based in Santa Cruz, California.

The cold waters off the Oregon coast usually support a robust community of copepods, a nutrient-rich type of zooplankton that provide an important food source for fish large and small, from herring to salmon. In 2014 as ocean temperatures rose, Fisher and other researchers began seeing copepods common farther south in warmer waters. Those warm-water creatures lack the lipids, the fat, that make their cold-water cousins so valuable for the species that consume them, like salmon.

“It’s like going from cheeseburgers to celery,” Mantua said. “The copepods are very small, very lean and it reduces efficiency all the way up to top predators.”

Mantua also noted that warmer water increases metabolic demands on fish so they get fewer nutrients from their prey while working harder to get it. “They’re getting hit on both ends,” he said.

In the warm waters of the first blob, other animals began showing up in strange places. Pyrosomes, free-floating organisms that look a little bit like a clear pickle, washed up on Oregon beaches by the thousands. In southern California, sea lions were forced to swim farther from their rookeries to feed and thousands of pups were left stranded on beaches.

Pyrosomes litter the deck of NOAA’s Bell M. Shimada research vessel during a cruise off the coasts of Oregon and Washington. Courtesy/Laurie Weitkam/NOAA FisheriesAP

In 2015, the biggest and most toxic algal bloom in human history developed, shedding domoic acid and shuttering crab fisheries up and down the West Coast.

A wait-and-see approach

Jennifer Fisher, a marine ecologist heading out on the Bell Shimada on Friday, knows what to look for. She’s been going out on the vessel for years and was there in 2014 when the first signs of The Blob became apparent.

She and the other researchers on the boat will be sending sensors down to the seafloor, taking a profile of the water column as they perform transects across a wide swath of ocean, as far south as the California border and north up to Grays Harbor, Washington.

They’ll be taking measurements of temperature, salinity and oxygen, to get an idea how deep the warm water goes, but Fisher will also be looking at what kind of microscopic organisms are populating Oregon’s coastal waters.

“I’m excited, but also nervous,” she said. “I hope we don't find a lipid-deplete ecosystem full of pyrosomes.”

It remains unclear whether the current heatwave is a blip on the radar or the beginning of a more troubling sequel to The Blob. As the seasons change, Mantua said he would be watching for what happens over the north Pacific.

“We’re transitioning from summer to fall and it’s a question of what we transition too. Whether it’s a more active pattern, or pattern that gets stuck,” he said. “We just have to wait and see.”

-- Kale Williams

kwilliams@oregonian.com

503-294-4048

@sfkale

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