Abstract
Investigation was conducted on the outbreaks of bloom Gephyrocapsa oceanica KAMPTMER in Tokyo Bay during the first two weeks of May 1995. The bloom broke out in Tokyo Bay early in May, spread to Sagami Bay and died out around May 20. According to our investigation, the bloom was 0.4m transparency, 117μg·l-1 chlorophyll, 1.5 X 105 cells·ml-1 of the total amount of plankton and 17.0 mg·l-1 dissolved oxygen (218.9% saturation). Compared to the bloom of diatom which often breaks out in Tokyo Bay, G. oceanica was much higher in turbidity. Observed values of fluorescene intensity in water and DO have indicated that the outbreakes of the bloom reached the peak from May 8 through May 10. Although the cause and mechanism of the outbreaks of bloom have remained unknownm, it is assumed that G. oceanica was led to Tokyo Bay by the meandering Japan Current and that conditions for its multiplication were met by the bay environment
