Ocean heat wave “blobs” are emerging in the world’s oceans, posing a serious threat to marine life.
A major heatwave that affected waters near the West Coast in 2014 and 2015 was nicknamed “the Blob” after the horror film. The new hot zone near California is being referred to in reports as a blob or return of the blob.
Here are some important facts to know about these temperature anomalies:
Scientists believe they’re caused by changes in the atmosphere
Andrew Leising, a research oceanographer with the National Oceanic and Atmospheric Administration’s Southwest Fisheries Science Center told The Hill that the oceanic heatwaves are likely caused by changes in atmospheric patterns.
“If the atmosphere patterns change so we don’t get a lot of wind and storms down at the surface of the ocean, then it doesn’t mix the water at the surface of the ocean and when you don’t mix the water around at the surface into the deeper waters, it just sits there and warms up,” he said.
“We get these big changes in atmospheric patterns that lead to a longer, larger period of calm winds and you don’t get the mixing and bam stuff starts heating up,” he added.
Rick Thoman, an Alaska climate specialist at the University of Alaska Fairbanks, told The Hill that high atmospheric pressure resulting in less wind and increased sunshine can be a cause of the heat waves.
They seem to be increasing in frequency and intensity
Nate Mantua, a supervisory research physical scientist with NOAA’s Southwest Fisheries Science Center, told The Hill that in recent years, evidence has been recorded of an increased frequency and intensity of ocean heat waves.
He partially attributed this to global warming, which has resulted in the ocean absorbing more heat.
“That just raises the baseline temperature everywhere so the warm periods today are added onto much warmer oceans,” he said.
Another factor Mantua attributed to these increases are changing weather patterns, which have led to changes in the way heat is moved in the ocean in different regions.
A 2018 study found that from 1925 to 2016, the average marine heatwave frequency increased by 34 percent and the average duration of a marine heatwave increased 17 percent. This resulted in a 54 percent increase in annual marine heatwave days around the world.
“These trends can largely be explained by increases in mean ocean temperatures, suggesting that we can expect further increases in marine heatwave days under continued global warming,” the study’s abstract said.
This has had a disastrous effect on marine life
The blob that impacted California starting in 2014 caused significant changes to the area’s marine life. According to NOAA, the hot spot caused the largest harmful algal bloom ever recorded on the West Coast, which halted crabbing and clamming for months.
It also stranded thousands of California sea lion pups on beaches. Changes in the marine food web caused mothers to forage for food further away and the young sea lions were left behind.
There were also multiple declared fishery disasters. Data from 2017 showed that 100 million pacific cod vanished from waters near southern Alaska possibly due to the blob, Science magazine reported. The fish’s population had decreased by 70 percent in two years.
The Post reported that the South Atlantic blob, first identified in 2012, similarly caused algae to bloom, clams to die and changes in fishing.
Repeated events can cause long term issues
Leising told The Hill that effects can be limited to the short term in isolated incidents, but repeated events can wreak havoc on certain species.
“When they just happen like for a year...it’s not too bad. A lot of the animals and populations can rebound,” he said. “If you string a bunch of these events together, that’s the kind of thing that some of these populations may have trouble recovering from.”
He said that a species lifespan can determine if it can weather repeated events. He noted that longer-living creatures can outlast heatwaves and microscopic creatures can easily bounce back , but those whose life cycles are in the middle are hard hit.
“If they have a bunch of years of bad reproduction, it starts stacking up on them,” he said of species with medium-length life cycles such as salmon.
He also noted that animals with the ability to move, like squid, can also evade issues but those that don’t, like rockfish, are likely to be impacted.
Economies are also being hit
Industries based on marine life such as fishing are being hurt by changing ocean ecosystems. After the West Coast heat “blob” of 2014 and 2015, NOAA declared multiple fishery disasters and gave out disaster relief to those determined to be impacted.
A request for one such declaration, regarding a California Sea Urchin Fishery, stated that “persistent warm ocean conditions” resulted in less kelp production which led to urchin starvation. It said that revenue ports in various parts of the state fell significantly, including by 93 percent in Orange County compared to a 5-year average.
“The Pacific sardine disaster, the salmon disaster and the crab disaster...those are really kind of three of our most important fisheries. They all basically had disasters as a result of this,” said Geoff Shester, the California campaign director and senior scientist of conservation group Oceana, referring to the effects of the 2014 and 2015 heatwave.
“The federal government essentially used taxpayer money to pay a bunch of folks back,” he added.