The California Current is a conveyor belt for cold water from the north Pacific.

It’s the reason that wetsuits are such big sellers in California. The river of ocean water known as the California Current barges in off the Aleutians, and as it rolls southward along the West Coast, makes for more than bone-chilling body surfing. It supports a robust stew of sea life.

But as Mike Lee reports for The San Diego Union-Tribune, it’s warming up. And that has researchers at the Scripps Institution of Oceanography concerned about future biodiversity off the California coast. Scientists say shellfish are already under attack from acid levels elevated when the ocean is forced to absorb more carbon dioxide from the atmosphere.

A schematic of the "food web" fostered by the California Current. Note the upwelling effect near the coastline, sometimes described as the "elevator" of the ocean food chain. (Image: Scripps Institution of Oceanography)

The Scripps researchers are just one section in the recent chorus raising alarms about the state of the oceans. This week Richard Black writes for the BBC that a British panel of scientists has concluded that the world’s oceans are in even worse shape than we thought, describing the current condition of the oceans as “critical.”

The warning shot, from a group of scientists known as the International Programme on the State of the Ocean (IPSO) is a preview of its comprehensive report, due out next year.