Black abalone populations are threatened by withering syndrome, a lethal disease whose cause remains unidentified. The symptoms of the disease are atrophied tissues and discoloring of the epipodium or other tissues. Individuals afflicted by the disease have a reduced foot and are weak, emaciated, and lethargic. The Fish and Game Commission has closed the black abalone fishery to protect the remaining healthy reproductive population for future genetic diversity. The hope is that remaining stocks may be resistant to the disease. Black abalone are found in central and southern California. The disease has been reported as far south as southern California and as far north as San Luis Obispo county. There are no known populations in the south that are unaffected. The disease was first observed on Santa Cruz and Anacapa islands in 1986 and has since spread to other islands and the mainland. Any abalone, including other species, observed with withering syndrome should be reported to Fish and Game, especially north of Point Conception. - WV
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