Saving Seafood

New global forecasts of marine heatwaves foretell ecological and economic impacts

April 22, 2022 — Researchers have developed global forecasts that can provide up to a year’s notice of marine heatwaves, sudden and pronounced increases in ocean temperatures that can dramatically affect ocean ecosystems.

The forecasts described in the journal Nature could help fishing fleets, ocean managers, and coastal communities anticipate the effects of marine heatwaves. One such heatwave, known as “the Blob,” emerged about 2013 in the northeast Pacific Ocean and persisted through 2016. It led to shifting fish stocks, harmful algal blooms, entanglements of endangered humpback whales, and thousands of starving sea lion pups washing up on beaches.

“We have seen marine heatwaves cause sudden and pronounced changes in ocean ecosystems around the world, and forecasts can help us anticipate what may be coming,” said lead author Michael Jacox, a research scientist at NOAA Fisheries’ Southwest Fisheries Science Center in Monterey, California, and NOAA’s Physical Sciences Laboratory in Boulder, Colorado.

Marine heatwave forecasts will be available online through NOAA’s Physical Sciences Laboratory. The researchers called the forecasts a “key advance toward improved climate adaptation and resilience for marine-dependent communities around the globe.”

Read the full story at ScienceDaily

Species may swim thousands of kilometers to escape ocean heat waves

August 11, 2020 — When an intense heat wave strikes a patch of ocean, overheated marine animals may have to swim thousands of kilometers to find cooler waters, researchers report August 5 in Nature.

Such displacement, whether among fish, whales or turtles, can hinder both conservation efforts and fishery operations. “To properly manage those species, we need to understand where they are,” says Michael Jacox, a physical oceanographer with the National Oceanographic and Atmospheric Administration based in Monterey, Calif.

Marine heat waves —  defined as at least five consecutive days of unusually hot water for a given patch of ocean — have become increasingly common over the past century (SN: 4/10/18). Climate change has amped up the intensity of some of the most famous marine heat waves of recent years, such as the Pacific Ocean Blob from 2015 to 2016 and scorching waters in the Tasman Sea in 2017 (SN: 12/14/17; SN: 12/11/18).

“We know that these marine heat waves are having lots of effects on the ecosystem,” Jacox says. For example, researchers have documented how the sweltering waters can bleach corals and wreak havoc on kelp forests. But the impacts on mobile species such as fish are only beginning to be studied (SN: 1/15/20).

Read the full story at Science News

New Research Reveals Clearer Picture of Upwelling That Feeds West Coast Marine Ecosystem

May 13, 2019 — The following was released by NOAA Fisheries:

Great volumes of nutrient-rich water welling up from the deep ocean fuel the West Coast’s great diversity of marine life. Now scientists using satellite images, research buoys, ocean models, and other ocean monitoring tools have brought the upwelling into much sharper focus, measuring even the velocity of the water and the amount of nutrients that it delivers.

Scientists described new “upwelling indices,” which represent a breakthrough in understanding the biological engine that drives the West Coast marine ecosystem.

“Upwelling is vital to marine life along the West Coast, but the tools we were using to monitor it hadn’t changed much in almost 50 years,” said Michael Jacox, a research scientist at NOAA Fisheries’ Southwest Fisheries Science Center who developed the new indices. “Now we’re bringing state-of-the-art tools and the latest science to bear to help us understand how upwelling supports and shapes the California Current Ecosystem.”

Given the ecological importance of upwelling, scientists and managers are eager for indices that allow them to monitor its variability and understand its impacts on coastal ocean ecosystems.

Jacox, of the Southwest Fisheries Science Center and NOAA’s Earth System Research Laboratory, and other researchers from NOAA Fisheries, and the University of California at Santa Cruz, recently published the new upwelling measurements new upwelling measurements in the Journal of Geophysical Research: Oceans and the indices are also available online. Maps based on the indices reveal through color-coding where upwelling is most pronounced, such as off Cape Mendocino in California.

Upwelling occurs along certain coastlines around the world where winds and the Earth’s rotation sweep surface waters offshore, drawing deep, cold, and salty water full of nutrients up to the surface. These nutrients fuel growth of phytoplankton that form the base of the marine food web, and ultimately nourish the West Coast’s ocean ecosystem from sardines to sperm whales.

Read the full release here