The California Coastal Commission decided Monday to continue allowing up to 4,300 off-road vehicles a day at the only beach in the state where they still are allowed to zoom among sand dunes.
The temporary limit on the number now using the beach was set for Oceano Dunes just south of San Luis Obispo. The Sierra Club had hoped for a ban to protect the endangered snowy plover, least tern, red-legged frog and steelhead trout.
The commission also ordered a review of how the dune buggies, all-terrain vehicles, campers, trucks and cars affect endangered species. Its first report, which could lead to changes in the vehicle limit, is due next January.
Supporters of dune driving say they are a lesser threat to endangered species than natural predators.
"If you take us away you are still going to have the issues," said Kim Kammer, a representative of the California Off-Road Vehicle Assn.
Opponents argue that vehicles carve up bird habitat in the dunes, creating runoff that affects fish and frogs.
"The ultimate goal would be to create a safe and healthy coastal ecosystem that is suitable for both wildlife and recreation," said Mark Massara, a Sierra Club attorney.
Having a million vehicles a year share the dunes with endangered animals is a "risky and dangerous proposition," he said.
Massara noted that the commission recently began preventing even pedestrians from walking on the beach near Vandenberg Air Force Base to protect endangered species there.
"The Coastal Commission has approved relatively drastic prohibitions throughout the rest of the state of California and we can't even get any reductions in a million vehicles a year," he said. "Every bit of wildlife is endangered by this activity."
But Kammer said the use of the dunes has decreased considerably in the last two decades. Off-road vehicles are allowed on 1,500 acres, compared with 15,000 acres before 1982. Off-roaders were allowed to drive along 15 miles of the beach before; now they are limited to five miles, including 3.3 miles for dune driving.
"Are we trying to save the endangered species, or are we trying to save the park?" asked Jim Suty, a member of Friends of Oceano Dunes, which is in favor of off-roading. "That is our land. We, the public, want our land."