White abalone, a Southern California native and the first marine invertebrate to be placed on the endangered species list, is seeing some positive progress toward recovery. UC Davis Bodega Marine Laboratory has been successful at breeding the mollusk in captivity thanks to a combination of temperature and lighting cues. In other words: ambience.
Since 2003, the researchers tried to coax the captive white abalone into mating to no avail but last year they finally had success. The first spawn of abalone has now made it past its first year—a very promising sign! Researchers report that there are about 125 abalone, including 60 adults, living in the program now.
Once the captive population has grown, the scientists plan to repopulate the subtidal zone of Southern California by replanting. It is thought that this program is the last hope for white abalone populations to rise again in the wild.
Abalone have a high mortality rate with about 99 percent never reaching adulthood. In the wild, white abalone males and females are so spread apart following years of overfishing that their broadcast spawning is rendered ineffective.
Carbon dating on their shells has shown scientists that most of the white abalone found in Southern California oceans have passed their reproductive age. They fear that the species is only 10 to 15 years from complete extinction.
Populations of red abalone in the Monterey Bay all the way to Crescent City have fortunately been subject to heavy regulation and study. There is current research being conducted that is exploring whether blanket regulation or regional regulations are most effective due to major differences in abalone populations along the coast.
Currently, abalone are enjoying respite after decades of overfishing, although populations are slow to recover. No abalone diving is permitted south of San Francisco Bay and divers are not allowed to use SCUBA gear—they must hold their breath for the dive.
We wish UC Davis researchers and their partners luck in replenishing Southern California oceans with white abalone. The scientific community is playing an integral part in giving marine animals the chance they deserve to rebound.
|picture courtesy of NOAA|