Invasive crabs and snails threaten oyster reefs in California coastal estuary

Washington, July 18 (ANI): In a study, scientists have found new evidence of invasive species threatening native ones, in the form of oyster reefs in a once-pristine California coastal estuary devastated by invasive Atlantic Coast crabs and snails.

Led by marine biologist David L. Kimbro, now of The Florida State University Coastal (FSU) and Marine Laboratory, the study shows that in Tomales Bay, half the population of California's native Olympia oyster has perished because its habitat has fallen victim to the dysfunctional relationship between native species and non-native ones accidentally introduced.

The work of Kimbro and colleagues from the University of California-Davis and its Bodega Marine Laboratory has magnified concerns that predator-prey mismatches between native and exotic species may lead to further losses of critical habitats that support marine biodiversity and ecosystems.

"What David Kimbro's research reveals about California's Olympia oyster raises a specter for Florida as well," said Felicia Coleman, director of the FSU Coastal and Marine Laboratory.

"These oysters are sustainably harvested and provide critically important settlement habitat for an amazing array of species, so its loss would be devastating," she added.

The study is expected to help guide habitat management and conservation efforts, including plans now being drawn up along the West Coast to restore native oysters.

"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.

According to said Kimbro, the artificial predator-prey mismatch has allowed high numbers of invasive snails to destroy the biological diversity of Tomales Bay, a coastal estuary about 40 miles northwest of San Francisco, by consuming and eliminating oyster habitat.

Ecological consequences are profound when the species most affected by a predator-prey mismatch is a "foundation species" that supports biodiversity by creating extensive habitat, such as California's native Olympia oyster, which provides critical nursery habitat for a suite of species including crabs, anemones and fishes.

Once upon a time, native oysters enjoyed a release from predation in the inner bay - that is, until the invasive species moved in. (ANI)