Bull. Jpn. Soc. Fish. Oceanogr. 70(1), Page 23-30, 2006   Influence of estuarine circulation on the biological production of the northern Hiroshima Bay, Japan, in summer season Toshiya Hashimoto*1, Akiko Ueda1 and Tamiji Yamamoto1 1Graduate School of Biosphere Science, Hiroshima University, 1–4–4 Kagamiyama, Higashi-Hiroshima, Hiroshima 739–8528, Japan †e-mail: