Tag Archives: north pacific ocean

NOAA Reports Latest Blob Shrinking Since Late August But Still One Of North Pacific’s Largest

THE FOLLOWING IS A NATIONAL MARINE FISHERIES SERVICE STORY

The vast marine heatwave that spread warm temperatures across the northeast Pacific Ocean late in the summer and fall of 2019 has declined in size and pulled back from the West Coast, possibly reducing its immediate impacts on coastal ecosystems.

N.O.A.A. REPORTS THAT THE LATEST BLOB, OR MARINE HEAT WAVE, THE GIANT POOL OF OCEAN WATER THAT IS ABOVE AVERAGE SEA SURFACE TEMPERATURES, HAS SHRUNK SINCE LATE AUGUST, BUT STILL AMONG THE FIVE LARGEST ON RECORD. (NOAA)

It has declined to about half the size and intensity it displayed in August. However scientists caution that the heatwave designated MHW NEP19a remains two to three times the size of Alaska and still retains enormous amounts of heat in the upper layers of ocean. It remains one of the top four or five largest heatwaves on record in the North Pacific in the last 40 years.

“What we are seeing now is a smaller heatwave that is farther offshore, but there is still a very large span of the Pacific Ocean that is much warmer than usual,” said Andrew Leising, a research scientist at NOAA Fisheries’ Southwest Fisheries Science Center (SWFSC) in La Jolla, California. Leising has developed criteria to detect and gauge the size and magnitude of marine heatwaves. “The question is, where does it go from here? That’s what we’re watching now.”

The edge of the heatwave is now about 1,500 kilometers (about 930 miles) from the West Coast, but still envelops much of the Gulf of Alaska. It no longer so closely resembles the enormous earlier marine heatwave known as “the Blob” that affected much of the West Coast through 2014 and 2015, causing reverberations through the food web.

Low salmon returns to many West Coast rivers in the last few years have been linked to the Blob, which reduced the availability of food when the salmon first entered the ocean as juveniles.

Both the Blob and the current heatwave were large and carried a great deal of heat. But this summer’s warming near the West Coast did not reach as deep into the ocean or last as long, said research scientist Michael Jacox of the SWFSC. “It will be very interesting to compare the two events and their impacts on marine life and fisheries given the different character and timeline,” he said.

Scientists will be watching for effects of the current heatwave on species such as salmon and albacore that are sensitive to ocean conditions, said Elliott Hazen of the SWFSC. “Is this going to be a similar ecological response to what we saw in 2014-2015, not much of a response given we are still recovering, or something quite different?” he asked.

Leising noted that as the Blob of 2014-2015 grew and evolved, it also experienced some weakening in 2013 before regaining strength and then expanding in size. That doesn’t mean the current heatwave will do the same. But it does underscore how much and how fast marine heatwaves can shift and change in response to climate and other factors.

“This marine heatwave is still with us in a big way,” he said. “While it’s not directly impacting the coast as much at this point, we still have a lot to learn about how these events grow and evolve.”

NOAA’s latest North American Multi-Model Ensemble forecasts through May 2020 predict a gradual weakening of the offshore warming. The NOAA Climate Prediction Center’s November 4 Diagnostic Discussion notes that tropical conditions this fall have been near normal, and this is projected through spring 2020.  If a tropical El Niño event develops this fall or winter instead, it would favor wind, weather, and ocean current patterns that could cause a return of the nearshore warming along the West Coast in winter or spring 2020.

NOAA Warning Of New Blob Off Northwest Coast

Federal oceanographers say a new Blob has formed in the North Pacific off the Northwest Coast in recent months and is already second in size to the one earlier this decade that hit salmon and other marine life hard, led to a nearly snowless winter in parts of the region and elevated summer temperatures.

GRAPHICS FROM NOAA SHOW THE ORIGINAL BLOB AND THE NEW ONE THAT HAS FORMED IN THE NORTH PACIFIC. (NOAA)

“It’s on a trajectory to be as strong as the prior event,” said Andrew Leising, a research scientist at the National Oceanic and Atmospheric Administration’s Southwest Fisheries Science Center in California in a story out ahead of a press call at noon. “Already, on its own, it is one of the most significant events that we’ve seen.”

Researchers are monitoring the new marine heatwave’s development and say that despite typical coastal upwellings that keep nearshore waters cooler in summer, warm water appears to have moved onshore to the Washington Coast.

Westport and Ilwaco anglers have reported catching numerous more southerly species, including yellowtail, bluefin and mahi mahi, and last week a 7-plus-foot-long striped marlin was caught off Garibaldi, on Oregon’s North Coast.

According to the Southwest Fisheries Science Center, that species of marlin is usually only seen as far north as Southern California‘s Channel Islands.

A SCREEN GRAB FROM A USGS VIDEO SHOWS A SOCKEYE SUFFERING FROM LESIONS SWIMMING AROUND DRANO LAKE IN AN ATTEMPT TO ESCAPE THE HOT WATERS OF THE COLUMBIA MAINSTEM DURING 2015’S BLOB EVENT. (USGS)

Still, there is some uncertainty in how bad this new blob might get. NOAA says it’s still early and it could break up or moderate as fall cools.

“It looks bad, but it could also go away pretty quickly if the unusually persistent weather patterns that caused it change,” said Nate Mantua, a federal research scientist formerly with the University of Washington.

UW atmospheric scientist Cliff Mass called it “a junior Blob” on his blog yesterday for how relatively recently it has formed. He notes the variance from normal sea surface temperatures is up to 7.2 degrees Fahrenheit, among “some of the most unusually warm water across the planet” at this moment.

Only portions of the west coast of Greenland and Arctic nearshore areas compare.

The 2014-15 blob was the largest marine heatwave in 40 years, according to the feds, and this new one is “almost the same size.”

The winter of 2014-15 saw rain in the Northwest’s mountains, leading to a snow drought that by summer had fishery managers restricting angling to protect fish in record-low, warm streams.

2015’s Puget Sound pinks and coho came in small and starving because of how bad ocean feeding conditions were for them, but 2019’s pinks have been good sized. It’s likely the former year-class were exposed for a longer period to the original blob than the latter fish to the new one.

NOAA’s story continues, saying:

A key question is whether the new heatwave will last long enough to affect the marine ecosystem. Biologists say that its large size means it probably already has. For example, warmer conditions during “the Blob” left lesser-quality food available to young salmon entering the ocean. It also shifted predator distributions in ways that contributed to low returns of salmon.

Other impacts linked to the earlier heatwave include:

  • The largest harmful algal bloom recorded on the West Coast, which shut down crabbing and clamming for months.
  • Thousands of young California sea lions stranding on beaches.
  • Multiple declared fishery disasters.

NOAA Fisheries scientists recently convened a special meeting to discuss the emerging heatwave and how to anticipate and track its effects. They are now reviewing impacts documented during the “the Blob” to compare them against the effects of the emerging heatwave.

“Given the magnitude of what we saw last time, we want to know if this evolves on a similar path,” said Chris Harvey, a research scientist at the Northwest Fisheries Science Center.