1. 1) Matsukawa, Y., Cho, N., Katayama, S. and Kamio, K. : Factors responsible for the drastic catch decline of the Ma nila clam Ruditapes philippinarum in Japan, NIPPON SUISAN GAKKAISHI, Vol. 74, No. 2, pp. 137-143, 2008.
2. 2) Uchida, M. : Comparison of productivity and biodiversity in domestic clam fishery, 2014 Seto Inland Sea Area Fisheries Research Institute Research Result Presentation, pp. 3-4, 2014.
3. 3) Yamamoto, T. : Oligotrophication and fisheries in the Seto Inland Sea, Journal of Water and Waste, Vol. 50, No. 2, pp. 525-532, 2008.
4. 6) Kuwae, T. : Factors affecting nutrient cycling in intertidal sandflats, Report of Port and Airport Research Institute, Vol. 41, No. 1, pp. 91-134, 2002.
5. 7) Yamaji, M. : Seasonal changes in glycogen contents of the Japanese Littleneck Clam, Ruditapes philippinarum from the coast of Urasaki, Etajima Bay in the Hiroshima Coast, Hiroshima Prefectural Technology Research Institute Fisheries and Ocean Technology Center Research Report, Vol. 4, pp. 21-524, 2011.