California oysters threatened

SAN FRANCISCO, July 19 (UPI) -- Oysters in an estuary near San Francisco are victims of humans moving species beyond their natural borders, a marine scientist said Saturday.

Tomales Bay contains oyster reefs attacked by invasive Atlantic Coast crabs and snails, marine biologist David L. Kimbro of The Florida State University Coastal and Marine Laboratory, Tallahassee, said. In a press release from the university, Kimbro said half the population of the Olympia oyster has lost its habitat to the invaders that were accidentally introduced.

Kimbro worked with scientists at the Bodega Marine Laboratory at the University of California-Davis and their findings increased concerns more habitat loss will come from predator-prey mismatches between native and exotic species.

The team's work could assist habitat management and conservation efforts, including plans to restore native oysters to the West Coast.

"We've identified what my California colleagues call 'an important restoration bottleneck,' the attack on oysters by invasive species, which must be dealt with prior to undertaking oyster population enhancement and the rebuilding of remnant reefs," Kimbro said.