For now, the world’s oceans are sucking up so much carbon dioxide that it’s helping to slow the rate of global warming. But that’s expected to change in the future, researchers warned after taking a detailed look at the rate of ocean acidification in the northeast Pacific Ocean. Continue reading “How long can the oceans soak up CO2?”→
El Niño a key factor, but global warming to increase marine heatwaves
A disruptive ocean heatwave in the northeastern Pacific Ocean in 2014 and 2015 was probably a manifestation of El Niño, says a new study by scientists with the Georgia Institute of Technology and the National Oceanic and Atmospheric Administration (NOAA).
New research offers clues on global pollution pathways
Polluted dust from Asia is cutting oxygen levels in the tropical Pacific Ocean, researchers said this week, releasing a new study that traces a chain reaction that starts with land-based industrial pollution in China and other Asian countries.
“There’s a growing awareness that oxygen levels in the ocean may be changing over time,” said Taka Ito, an associate professor at Georgia Tech’s School of Earth and Atmospheric Sciences. “One reason for that is the warming environment – warm water holds less gas. But in the tropical Pacific, the oxygen level has been falling at a much faster rate than the temperature change can explain,” Ito said.
Warm ocean temperatures in the Pacific led to what researchers now are calling an unprecedented bloom of toxic algae along the west coast of North America in 2015. The algal toxin domoic acid was found in samples from a wide range of marine organisms — and for the first time, in the muscle tissue of several commercial fish species.
Scientists from the University of California, Santa Cruz led the investigations into the spread of the toxin through the marine food web, finding that it persisted in Dungeness crab months after the algal bloom disappeared from coastal waters.
Domoic acid is a potent neurotoxin produced by a type of microscopic algae called Pseudo-nitzschia that occurs naturally in coastal waters. Blooms of the toxic algae along the California coast typically occur in the spring and fall and last just a few weeks. This year, however, unusual oceanographic conditions (unrelated to El Niño) led to the largest and longest-lasting bloom ever recorded. Continue reading “Algae toxin found in West Coast fish for first time”→
Climate change will likely subject many low-lying Pacific island nations to more extreme fluctuations in sea level from year to year, in synch with more intense El Niño cycles. Some years, high sea level will lead to bigger floods, while in other years, big drops in sea level will leave coral reefs exposed, according to researchers based in Hawaii and Australia. Continue reading “Pacific islands face extreme sea level changes”→