Sustainable use of precious coral

 
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 Precious coral has been used as jewelry and also appeared in pictures and stories as a symbol of treasure, which has enriched our lives. We propose the following to achieve the sustainable fishery of this precious coral.

1. Selective fishing, and fishing suspension or rotational fishing
 The size-age structure of Japanese red coral, Paracorallium japonicum colonies in the sea around the Amami Islands, southern Japan was investigated, which confirmed that the colonies reach the harvestable size in 10-20 years of fishing suspension (Fig. 1). To use this resource sustainably, only a certain size of coral should be harvested using selective fishing gears such as remotely operated vehicles. Also fishing areas should be closed for 10-20 years. Or allocating areas for fishing closures on a rotational basis would be a useful conservation effort.

2. For the preservation of this resource, fishing should be prohibited in areas precious corals occur in high density or areas they preserve high levels of genetic diversity.

3. To maintain steady-state recruitment, fishing should be prohibited during the reproductive season. In Kochi Prefecture, June and July, the reproductive season of precious coral in Tosa Bay, have been designated as the closed season since March 2012.。 (Nozomu Iwasaki of Rissho University)

[Reference]
●Iwasaki. N., Fujita. T., Bavestrello. G. and Cattaneo-Vietti. R., 2012. Morphometry and population structure of non-harvested and harvested populations of the Japanese red coral (Paracorallium japonicum) off Amami Island. southern Japan. Marine and Freshwater Research, 51(3). 372-382.

 

Fig. 1  
Fig. 1. The size-age structure of Japanese red coral in a harvested and a non-harvested area off the Amami Islands, southern Japan: The size peak of corals harvested coincides with that of corals in the non-harvested area, indicating that corals of that size are not caught in the non-harvested area. Meanwhile, the harvested area has no corals of that size, demonstrating that it would take younger colonies 10-20 years to reach the harvestable size (R).