A new marine heat wave — similar to a 2015 event nicknamed “The Blob” — has formed off the coast of British Columbia, according to the National Oceanic and Atmospheric Administration.
About five years ago, “The Blob,” an expanse of warm ocean water, disrupted the west coast marine ecosystem and affected salmon returns. Scientists say the new expanse of “unusually warm water” has grown in the same way, in the same area, to almost the same size.
However, the system may not last as long.
According to the National Oceanic and Atmospheric Administration (NOAA), the new heat wave emerged over the past few months. A ridge of high pressure dampened the winds that otherwise mix and cool the ocean’s surface. The heat wave is still relatively new and is primarily affecting the upper layers of the ocean. It could break up rapidly.
“It looks bad, but it could also go away pretty quickly if the unusually persistent weather patterns that caused it change,” Nate Mantua, a research scientist at the NOAA Fisheries’ Southwest Fisheries Science Center in La Jolla, Calif., said in a release Thursday.
The warm expanse building off the B.C. coast stretches roughly from Alaska south to California. It ranks as the second-largest marine heatwave in terms of area in the northern Pacific Ocean in the last 40 years, after “the Blob.” That event peaked through 2014 and 2015 with temperatures close to seven degrees Fahrenheit (4 C) above average.
“It’s on a trajectory to be as strong as the prior event,” Andrew Leising, a research scientist at the Southwest Fisheries Science Center, said in a statement.
According to the Leising, cold water coming from the ocean depths along the coast has held the warm expanse offshore. However, this upwelling, driven by coastal winds, usually wanes in the fall. The heat wave could then move onshore and affect coastal temperatures.
The NOAA said this has already appeared to have happened along the coast of Washington state.
Current forecasts show the heat wave moderating but continuing for months. Biologists say the large size of the heat wave means it has probably already affected the ecosystem.
During “The Blob,” lesser-quality food available to young salmon entering the ocean. It also shifted predator distributions in ways that contributed to low returns of salmon.
There was also 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, and multiple fishery disasters declared.
U.S. scientists said they will continue to monitor the system.
“There are definitely concerning implications for the ecosystem,” Nick Bond, a research meterologist with the Joint Institute for the study of the Atmosphere and Ocean in Seattle who is credited with naming “the Blob, said in a statement.
“It’s all a matter of how long it lasts and how deep it goes.”