The arrival of a marine heat wave much like “the Blob” of a few years ago may mean trouble for sea life and habitats on the West Coast.
Scientists are tracking the heat wave they say is similar to the one seen in 2014 and 2015 that disrupted marine ecosystems, and affected marine mammal populations and fisheries from Alaska to Southern California.
Dubbed the “Northeast Pacific Marine Heatwave of 2019,” the new climate event was announced at a news conference Thursday, Sept. 5, by the Northwest Fisheries Science Center and Southwest Fisheries Science Center, part of the National Oceanic and Atmospheric Administration.
Scientists warn the expanse of unusually warm water has quickly grown to a similar size and area as “the Blob” of five years ago.
“We really want to stress that when we talk about ‘the Blob’ that we are keeping to that, that event that occurred in 2014,” said Andy Leising, a research scientist at the Southwest Fisheries Science Center in La Jolla. “This is a new, different event based on its location and year of its formation.”
The new marine heat wave already is the second largest in the northern Pacific Ocean in the last 40 years, after “the Blob,” said Leising, who developed a system for tracking and measuring heat waves in the Pacific Ocean using satellite data.
In the early stages of “the Blob,” he said, water temperatures climbed almost seven degrees above average.
Researchers have been tracking the Northwest Pacific Marine Heatwave since fall, but it dissipated before re-gaining strength in mid-June.
Research scientist Nathan Mantua, of the Southwest Fisheries Science Center, said this latest event is being caused by a persistent pattern of weaker-than-normal winds over the area that goes in a triangle from Hawaii to British Columbia to Southern California.
The marine heat wave doesn’t necessarily mean Southern California waters will stay balmy and warm into fall like they did in 2014 and 2015. During “the Blob” years, there actually were two warm water events – one closer to Southern California and the other near the Gulf of Alaska – that eventually merged to make one big one, Leising said.
“We just had warm blob everywhere,” he said. “The difference this year is that the feature forming in the Gulf of Alaska is similar in size and shape, but we’re missing that one off of Southern California … we have not really had the impacts yet.”
Deeper waters are not as warm as the previous event, he said, and if the atmosphere changes, warm water could go away rapidly.
“We’re not necessarily expecting it to keep going the same way ‘the Blob’ did,” he said. “Only time will tell if this thing persists.”
Among the local impacts may be open ocean animals that like warm water coming closer to shore. That would include certain species of plankton, sea snakes and – good news for anglers – tuna.
“The tuna don’t really care what’s causing the warm water, as long as there is warm water,” Leising said. “But we haven’t really seen that yet in Southern California, nor do we expect that to happen.”
So far, northern regions of the West Coast have been most affected, he said. Salmon fisheries may be impacted, and commercial fishing operations may have a tough time finding krill.
“A lot of the productivity and availability of seafood is affected by climate patterns and weather patterns,” said Chris Harvey, a research fisheries biologist with the Northwest Fisheries Science Center. “If productivity levels are changing because of weather or climate events, we have to adjust the amount we’re catching so we don’t over-catch them.”
Squid, for example, could move farther north into Oregon and Washington rather than where they are usually found, in Central and Southern California.
Another species that showed a shift in behavior during “the Blob” years was the humpback whale, which started feeding closer to shore.
While that was great for whale-watching businesses, it also led to a record number of entanglements from crab traps and other fishing gear. Fishermen, managers, and others have formed working groups in California, Oregon, and Washington to find ways of reducing the risk of entanglements.
Another major concern is a harmful algae bloom that showed up with “the Blob” along the entire West Coast, said Stephanie Moore, research oceanographer for Northwest Fisheries Science Center.
That bloom not only shut down Dungeness crab fisheries, but also recreational shell fishing including razor clamming in Washington and Oregon.
The algae bloom also created a “domoic acid” outbreak that affected anchovies and sardines that stranded and caused a large number of sea lion and dolphin stranding and deaths.
“These fish became these little toxic bullets for their predators,” Moore said. “We will be watching very closely what happens here in the next six months from now, if this heat wave continues. … That’s when there could be risk of another bloom of that magnitude.”
Chris Lowe, director of the Shark Lab at Cal State Long Beach, wonders what warm water off the Southern California coast could mean for migration patterns for marine species, including juvenile white sharks, and if they would stick around like they did during “the Blob” years if the water doesn’t cool.
“There’s a sweet spot that juvenile white sharks like temperature-wise,” he said. “It’s usually 68 to 72 (degrees).”
Kelp might also take a hit, he said, not only because it doesn’t thrive in warmer waters but it needs the nutrients that usually comes from upwelling, water from deeper, colder areas of the ocean.
“It’s like a double whammy,” he said.
Lowe also wonders if other species — such as smooth hammerheads, mahi mahi or whale sharks — will show up from the south, but water temperatures usually have to be in the 70s and 80s for that to happen.
“What animals are doing, where they are moving is relative to water temperatures,” Lowe said. “They are following temperature gradients. Usually their food does too. That’s why we start seeing those animals in our neck of the woods that we don’t normally see.”
Source: Orange County Register