New research based on ocean models and near real-time data from autonomous gliders indicates that the “The Blob” and El Niño together strongly depressed productivity off the West Coast, with The Blob driving most of the impact.
The research published in the journal Geophysical Research Letters by scientists from NOAA Fisheries, Scripps Institution of Oceanography and University of California, Santa Cruz is among the first to assess the marine effects of the 2015-2016 El Niño off the West Coast of the United States.
“Last year there was a lot of speculation about the consequences of ‘The Blob’ and El Niño battling it out of the U.S. West Coast,” said lead author Michael Jacox, of UC Santa Cruz and NOAA Fisheries’ Southwest Fisheries Science Center. “We found that off California El Niño turned out to be much weaker than expected, The Blob continued to be a dominant force, and the two of them together had strongly negative impacts on marine productivity.”
“Now, both The Blob and El Niño are on their way out, but in their wake lies a heavily disrupted ecosystem,” Jacox said.
Unusually warm ocean temperatures that took on the name, The Blob, began affecting waters off the West Coast in late 2013. Warm conditions — whether driven by the Blob or El Niño — slow the flow of nutrients from the deep ocean, reducing the productivity of coastal ecosystems. Temperatures close to 3 degrees C (5 degrees F) above average also led to sightings of warm-water species far to the north of their typical range and likely contributed to the largest harmful algal bloom ever recorded on the West Coast last year.
“These past years have been extremely unusual off the California coast, with humpback whales closer to shore, pelagic red crabs washing up on the beaches of central California, and sportfish in higher numbers in southern California,” said Elliott Hazen of the Southwest Fisheries Science Center, a coauthor of the paper. “This paper reveals how broad scale warming influences the biology directly off our shores.”
Read more at ScienceDaily
Image: A close-up of sea surface temperatures off the West Coast, with red illustrating areas warmer than average and blue representing areas below average via NOAA
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