MORRO BAY, Calif.— The U.S. Fish and Wildlife Service today proposed changing the Endangered Species Act status of the Morro shoulderband snail from endangered to threatened.
Found only in the Los Osos and Morro Bay area of western San Luis Obispo County, the snail is thought to have a stable or increasing population and has benefitted from protection of coastal dune and sage-scrub habitat preserves.
“This is good news for one of the most laid-back native species on the SLO coast,” said Jeff Miller, a senior conservation advocate at the Center for Biological Diversity and a Los Osos resident. “Like everything it does, this snail is moving very slowly toward recovery. It evolved with our signature coastal dunes and scrub, so let’s keep it around for future generations to marvel at too.”
The Morro shoulderband snail lives in native vegetation on sandy soils of coastal dune and coastal sage scrub habitats. Its native range covers about 7,700 acres, extending from Morro Strand State Beach in northern Morro Bay southward to Montaña de Oro State Park and inland to eastern Los Osos.
The snails are named for the dark spiral band on the shoulder of their shells and are typically found in leaf litter and on the shady undersides of lower branches of native dune shrubs. They are active during rain and heavy fog but go dormant during the dry summer. Unlike invasive garden snails, they eat mostly fungal mycelia that grow on decaying plant matter, are not a garden pest, and help build up the soil.
“Recovery of this snail shows that if we want to save species from extinction, we have to protect the places they live,” said Miller. “Saving the snail has protected places we all love, making life better on the central coast.”
A recovery plan was prepared for the Morro snail in 1998, which identified four conservation planning areas to focus on habitat protection. The Center for Biological Diversity and Christians Caring for Creation secured protection in 2001 of 2,566 acres of critical habitat for the snail around the community of Los Osos and the Morro Bay Estuary. Blocks of protected and unfragmented habitat large enough to minimize the snail's risk of extinction have since been secured in Morro Spit, West Pecho, southern Los Osos and northeastern Los Osos.
Surveys from 2000-2005 found more and more snails each year in a wider variety of habitat types than previously thought. A 2006 status review by the Service concluded that the Morro snail population is stable to increasing and has a wider range and distribution than thought at time of listing.
Maturing vegetation in preserves such as Morro Strand State Beach, Los Osos Oaks State Preserve, Morro Bay State Park, Montana de Oro State Park and the Elfin Forest Reserve may require habitat maintenance and removal of invasive plants to provide long-term habitat for the snail. Recovery criteria have not been fully achieved, and some of the conservation areas still need management plans.
When the snail was protected as endangered in 1994, it was thought to be one of two subspecies of the banded dune snail, but was subsequently determined to be a separate species from the related Chorro shoulderband snail. The Morro snail occurs only on Baywood fine sand soils and the Chorro snail is associated with clay or serpentine soils. The Chorro snail was thought to be extinct but was rediscovered in 1999. It has since been found to be common to abundant at 20 locations from Cayucos to northern Morro Bay, inland to San Luis Obispo, and southeast to Edna. The Service is removing the Chorro shoulderband snail from the endangered species list.