Journal of Oceanography, Vol. 53 (No. 6), pp. 579-583, 1997
Faculty of Applied Biological Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-hiroshima 739, Japan
(Received 8 November 1996; in revised form 23 June 1997; accepted 24 June 1997)
Abstract: Abundance and production of bacterioplankton were investigated along with chlorophyll-a (chl-a) concentration over a transect through Ise Bay, Japan. The transect was designed to cross the thermohaline front of the bay, which assumes a distinct form in winter. Average bacterioplankton abundance was 6.4 × 109 cells l-1 in winter and 8.3 × 109 cells l-1 in summer. Average bacterioplankton production was estimated to be 13.8 mg C l-1 day-1 in winter and 35.6 mg C l-1 day-1 in summer. Chl-a maxima were observed in the inner area and the front area, while the maximum bacterioplankton abundance and production were found at the inner to innermost area of the bay. Thus, the bacterioplankton abundance or production in Ise Bay was not necessarily coupled with the front-associated chl-a maximum.