DISTRIBUTION OF AEROBIC BACTERIOCHLOROPHYLL-CONTAINING BACTERIA IN OTSUCHI BAY, IWATE

Distribution of aerobic bacteriochlorophyll-containing heterotrophic b acteria (ABHB) was examined for the seawater of Otsuchi Bay, Iwate, in 1992 and 1993. In 1993, the population of ABHB was highest on July 22 and its percentage in total aerobic heterotrophic bacteria counted on agar plates ranged from ca. 20 to 50%. ABHB was present at lesser ext ents in August and September but not found in neither May nor October. Increase of ABHB population was coincident with the development of st ratification in seawater, but did not seem to correlate with the chang e of solar radiation intensity. Higher proportions of ABHB were also f ound on July 14 of 1992, and were around 20%.