WHITE ABALONE } Haliotis sorenseni
DESCRIPTION: White abalone are ocean-dwelling mollusks with a thin, oval shell that is red or brown on the outside and a variety of iridescent colors, particularly white and pink, inside. They grow to a maximum length of 10 inches, and adults weigh between one and two pounds. Abalone shells are extremely strong, as are the tenacious orange “feet” of these snails, which they use to cling to rocks and other surfaces.
HABITAT: White abalone are found in open rock or boulder habitat interspersed with sand channels off the coast of California. This species is most abundant at depths between 80 and 100 feet, making it the deepest-occurring abalone in California.
RANGE: The white abalone, one of eight abalone species off the California coast, formerly occurred from near Point Conception, California to Punta Abreojos in Baja, Mexico. With the current status of the abalone in Mexico largely unknown, the species is today thought to exist in only a few locations near California's Channel Islands.
MIGRATION: White abalone do not migrate. Although juvenile abalone may move dozens of feet per day, the movement of adults becomes extremely limited as they increase in size.
BREEDING: Abalone reproduce by releasing their eggs and sperm into the surrounding water. For fertilization to occur, spawners need to be within three feet of a member of the opposite sex.
LIFE CYCLE: Only one day after fertilization, abalone eggs hatch into larvae, which float for a week or two. The larvae eventually metamorphose into the adult form and settle to the ocean floor. White abalone live for an estimated 30 to 40 years.
FEEDING: Algae is the main food source of abalone. An abalone eats by partially raising itself off its rock to capture pieces of algae as they drift by.
THREATS: White abalone were intensely harvested for commercial and recreational purposes during the 1970s. Fishing quickly peaked and crashed as the abalone became increasingly scarce. The subsequently low densities of abalone have resulted in repeated reproductive failure, making it unlikely that the species will recover on its own. Abalone are also threatened by global warming, ocean acidification, and bacterial and parasitic infections.
POPULATION TREND: The white abalone historically numbered between 2 and 4 million animals. Recent surveys estimate that only a few thousand remain. This decline represents a tragic example of how poor fisheries management has reduced a once-abundant species to such low levels that individuals are too far apart to successfully reproduce. Scientists have predicted that the species will be extinct within 10 years unless immediate action is taken.