五ケ所湾におけるGymnodinium mikimotoiの増殖ポテンシャル Growth Potential of Gymnodinium mikimotoi in Gokasho Bay
Algal growth potential (AGP) of <i>Gymnodinium mikimotoi</i> was examined at a sampling station situated in Gokasho Bay during a red tide period from 1991 to 1994. In the year 1991, 1992 and 1994 when the bloom of <i>G. mikimotoi</i> occurred, the high AGP of seawater at the depth of 1.0m above bottom (B-1m) was observed at the order of 10<sup>3</sup> cells/m<i>l</i> before the peak of the algae. But the AGP didnot increase during the period from June to August in 1993, the year of no development of <i>G. mikimotoi</i>. These results indicate the possibility of predicting red tide by AGP of seawater at the depth of B-1m.<br>The growth limiting nutrients in Gokasho Bay were also studied using AGP assay. The growth yield of <i>G. mikimotoi</i> was enhanced by the addition of phosphorus to filtered seawater prior to development of the algae. When the bloom of <i>G. mikimotoi</i> occurred, the lack of phosphorus was not found. Therefore, it was suggested that the nutrient factor which control development of <i>G. mikimotoi</i> red tide was phosphorus.
日本水産学会誌 63(4), 578-584, 1997-07-15