Oyster larvae have been dying by the billions. Scientists suspect it’s a sign that carbon dioxide is dramatically affecting the ocean.

By Craig Welch, Seattle Times environment reporter WILLAPA BAY, Pacific County — The collapse began rather unspectacularly. In 2005, when most of the millions of Pacific oysters in this tree-lined estuary failed to reproduce, Washington’s shellfish growers largely shrugged it off. In a region that provides one-sixth of the nation’s oysters — the epicenter of the West Coast’s $111 million oyster industry — everyone knows nature can be fickle. But then the failure was repeated in 2006, 2007 and 2008. It spread to an Oregon hatchery that supplies baby oysters to shellfish nurseries from Puget Sound to Los Angeles. Eighty percent of that hatchery’s oyster larvae died, too. Now, as the oyster industry heads into the fifth summer of its most unnerving crisis in decades, scientists are pondering a disturbing theory. They suspect water that rises from deep in the Pacific Ocean — icy seawater that surges into Willapa Bay and gets pumped into seaside hatcheries — may be corrosive enough to kill baby oysters. If true, that could mean shifts in ocean chemistry associated with carbon-dioxide emissions from fossil fuels may be impairing sea life faster and more dramatically than expected. …

Oysters in deep trouble: Is Pacific Ocean’s chemistry killing sea life?.