Pacific Ocean

Pacific West Coast Acidification Rate Larger than Other Oceans

The ocean absorbs carbon dioxide from the atmosphere, which reduces pH levels and concentrations of calcium carbonate, a mineral used by shellfish to calcify their shells. As more carbon is released into the atmosphere, concentrations of calcium carbonate decrease and the shells of organisms like foraminifera get thinner, a trend Osborne saw clearly in the sediment cores she examined.

“The shell thickness record instantly showed a long-term declining trend,” she said. “It was really obvious across entire record.”

Massive Marine Heat Wave Returns

The current expanse of warm water stretches from Alaska to Southern California to Hawaii. It appears similar to conditions five years ago when the original “blob” was first taking shape, federal scientists said, although so far, the warmer-than-normal waters extend down only about 150 feet below the surface, rather than 600 feet five years ago.