The federal government Friday proposed declaring the black abalone an endangered species, the first step in an effort to bring back the once-abundant mollusk ravaged by disease and excessive harvesting.
The final decision, expected to come after a year of study, would not have an immediate effect on the hunting of black abalone in California, which has been illegal since 1993.
But the listing could bring federal money to help restore population, set aside critical habitat and impose criminal penalties for importing the mollusk from Mexico.
Endangered status also could lead to a crackdown on power plants that use seawater as a coolant and release warmed water to the sea. Other activities that elevate seawater temperature could come under scrutiny. Warmer waters have been linked to the spread of bacteria that can be fatal to abalone.
Scientists who discovered a mass die-off of black abalone near the Diablo Canyon nuclear power plant in San Luis Obispo County in the 1980s believe it was directly linked to heated effluent from the plant, said Melissa Neuman, a fisheries biologist with National Marine Fisheries Service in Long Beach.
Because of their small size and tough flesh, black abalone were the least desirable of the abalone species that once blanketed the rocky underwater reefs off California. Their harvest was not common by commercial or recreational fishermen until white, pink, green and red abalone were depleted.
By 1997, state officials banned all abalone hunting off California, except for red abalone taken by sports divers without scuba gear north of San Francisco. White abalone were so rare they were placed on the federal endangered list in 2001, but the others are not listed.
Black abalone have suffered some of the greatest losses from excessive harvesting and disease outbreaks first spotted in the mid-1980s. Once piled atop one another, the black abalone are reduced to a couple of viable populations off Southern California's San Miguel and San Nicolas islands.
Black abalone are doing a bit better in colder waters north of Monterey, Calif., but scientists worry about the disease spreading north with rising sea temperatures attributed to global warming.
The National Marine Fisheries Service, which proposed adding the black abalone to the endangered species list after petitioning by the nonprofit Center for Biological Diversity, has a year to collect public comments, complete its scientific and legal analysis and make a final decision.