Withering Abalone Syndrome
Encyclopedia
Withering abalone syndrome is a disease of the abalone
shellfish
, primarily found in the black
and red abalone
species.
First described in 1986, it is caused by the bacterium "Candidatus
Xenohaliotis californiensis", which attacks the lining of the abalone's digestive tract, inhibiting the production of digestive enzymes. To prevent starvation, the abalone consumes its own body mass, causing its characteristic muscular "foot" to wither and atrophy
. This impairs the abalone's ability to adhere to rocks, making it far more vulnerable to predation
. Withered abalone not eaten by predators typically starve.
For reasons not yet well understood, some abalone can be infected with the bacterium without developing the disease. It is believed, however, that changes in environmental conditions, such as warmer than normal water temperatures, may induce the disease in abalone that already harbor the bacterium. For this reason, the spread of the bacterium could lead to further declines in abalone populations, especially during El Niño events, when water temperatures rise.
Once a valuable fishery
, abalone in Southern and Central California
have been decimated by commercial and sport fishing, and more recently by this disease. Some populations of black abalone have declined nearly 99 percent since the disease was first observed in the Channel Islands
off Santa Barbara
.
Abalone
Abalone , from aulón, are small to very large-sized edible sea snails, marine gastropod molluscs in the family Haliotidae and the genus Haliotis...
shellfish
Shellfish
Shellfish is a culinary and fisheries term for exoskeleton-bearing aquatic invertebrates used as food, including various species of molluscs, crustaceans, and echinoderms. Although most kinds of shellfish are harvested from saltwater environments, some kinds are found only in freshwater...
, primarily found in the black
Black Abalone
The black abalone, Haliotis cracherodii, is a species of large edible sea snail, a marine gastropod mollusk in the family Haliotidae, the abalones....
and red abalone
Red abalone
The red abalone, Haliotis rufescens, is a species of very large edible sea snail, a marine gastropod mollusk in the family Haliotidae, the abalones, ormer shells or paua....
species.
First described in 1986, it is caused by the bacterium "Candidatus
Candidatus
Candidatus is in scientific classification a component of the taxonomic name for a bacterium that cannot be maintained in a Bacteriology Culture Collection. It is an interim taxonomic status for noncultivable organisms. An example would be "Candidatus Phytoplasma allocasuarinae"...
Xenohaliotis californiensis", which attacks the lining of the abalone's digestive tract, inhibiting the production of digestive enzymes. To prevent starvation, the abalone consumes its own body mass, causing its characteristic muscular "foot" to wither and atrophy
Atrophy
Atrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations , poor nourishment, poor circulation, loss of hormonal support, loss of nerve supply to the target organ, disuse or lack of exercise or disease intrinsic to the tissue itself...
. This impairs the abalone's ability to adhere to rocks, making it far more vulnerable to predation
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
. Withered abalone not eaten by predators typically starve.
For reasons not yet well understood, some abalone can be infected with the bacterium without developing the disease. It is believed, however, that changes in environmental conditions, such as warmer than normal water temperatures, may induce the disease in abalone that already harbor the bacterium. For this reason, the spread of the bacterium could lead to further declines in abalone populations, especially during El Niño events, when water temperatures rise.
Once a valuable fishery
Fishery
Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...
, abalone in Southern and Central California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
have been decimated by commercial and sport fishing, and more recently by this disease. Some populations of black abalone have declined nearly 99 percent since the disease was first observed in the Channel Islands
Channel Islands of California
The Channel Islands of California are a chain of eight islands located in the Pacific Ocean off the coast of Southern California along the Santa Barbara Channel in the United States of America...
off Santa Barbara
Santa Barbara, California
Santa Barbara is the county seat of Santa Barbara County, California, United States. Situated on an east-west trending section of coastline, the longest such section on the West Coast of the United States, the city lies between the steeply-rising Santa Ynez Mountains and the Pacific Ocean...
.