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Article: Abalone resource decline and a recovery attempt in Chiba Prefecture, Japan.
- Article from:
- Journal of Shellfish Research
- Article date:
- December 15, 2004
- Author:
CopyrightCOPYRIGHT 2004 National Shellfisheries Association, Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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ABSTRACT Landings of abalone (H. discus, H. gigantea, and H. madaka) in Chiba Prefecture, Japan exceeded 700 t in 1966 and fluctuated between 600-800 t until 1978. The landings started to decline in 1979 and reduced to less than 100 t in 1997. Although landing of H. discus has been slightly increased since 2000, that of H. gigantea abalone is still decreasing. We analyzed the data of investigations on decline in abalone landings and have come up with "environment theory", "over-fishing theory" and "disease theory." In the environment theory various factors were considered, such as biomass decrease of purple sea urchin; which is used as a shelter by juvenile abalone, ...
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