As the Bluff oyster industry watches for hopeful signs of recovery, oyster fishers in the US are witnessing cause for concern, Craig Welch, of The Seattle Times, reports. Growers rely on wild oysters, which typically grow in clusters like this. Third-generation shellfish farmer Brian Sheldon now must turn to oysters started in hatcheries. Photo by MCT.

The collapse began rather unspectacularly. In 2005, when most of the millions of Pacific oysters in this tree-lined estuary failed to reproduce, the shellfish growers of Willapa Bay, Washington state largely shrugged it off. In a region that provides one-sixth of the nation’s oysters – the epicentre 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 US 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 is 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. …

Tide of acid-ocean fear rolls over oyster industry via Ocean Acidification