Chronicle readers left panicked by a July 6 article stating that San Francisco Bay's native oyster population had recently collapsed were presumably relieved two weeks later. A follow-up July 19 article gushed that more than $1 million is being sunk into a local shoreline habitat program to bolster native oyster and eelgrass populations.
Thank you, taxpayers, for bailing out the bay's battered bivalves.
But what if the local oyster collapse was just a figment of conservationists' imagination, penned by a reporter eager for the latest eco-scoop?
Andy Cohen, a San Francisco Estuary Institute scientist who founded the Center for Research on Aquatic Bioinvasions, strongly doubts whether the bay has harbored a major native oyster population in recent millennia, and doubts whether it could sustain one today. That puts him at odds with a litany of nonprofit and government officials who accuse humans of wiping the population out during the past two centuries.
Pointing to shells left behind in large piles by the Bay Area's original seafood shuckers, Cohen says the bay's oyster population crashed, naturally, at least 2,000 years ago, probably as the local climate grew unwelcoming. Most of the Ohlone tribal shell mounds were stacked with the remains of mussels and clams. "No one has produced a shred of evidence that native oysters were abundant," Cohen said. "No ethnographic evidence. No geologic evidence. Nothing."
But virtually the entire local conservation movement has spent years ignoring Cohen.
Backers of local oyster restoration projects acknowledge that the size of the bay's past oyster population remains a mystery. But they point to tantalizing hints of its presumed magnificence, such as references to a local oyster fishery sprouting in the 1840s.
Meanwhile, those most actively involved with the Restoring Living Shorelines project, which deposits cleaned shells of a different oyster species in hopes that native larvae settle inside and blossom, now say that it shouldn't matter when or why the oyster population collapsed: They want one to flourish in the future.
Sarah Newkirk, coastal project director with the nonprofit Nature Conservancy, which is donating the use of submerged land to the restoration project, said fostering native oysters would help stabilize shorelines, provide homes for smaller creatures that live on them, and help clean up water pollution. "We're increasingly not able to return places to a historic condition," she said. "The best we can do is to try to restore the natural functions of an ecosystem."
Which is fine. But it seems unhelpful to add an unsubstantiated eco-tragedy to our growing list of crises.