DISTRIBUTION OF VIRIOPLANKTON IN THE KUROSHIO CURRENT AND THE ADJACENT AREA IN THE EAST CHINA SEA AS DETERMINED BY FLOW CYTOMETRY

Distribution of one group of marine viral particles along the Kuroshio Current and theadjacent area was investigated in June, 1998 using flow cytometry for the first time. The position of thisgroup of virioplankton in flow cytometry plots coincided with the position of the V-I group reported byMarie et al. （1999）. Abundances of this group of virioplankton in the surface water ranged from 3.4×105 to 2. 3×106 ml-1 in the investigated area. High abundance occurred in the shelf water and low abun-

Distribution of one group of marine viral particles along the Kuroshio Current and the adjacent area was investigated in June, 1998 using flow cytometry for the first time. The position of this group of virioplankton in flow cytometry plots coincided with the position of the V-I group reported by Marie et al. (1999) . Abundances of this group of virioplankton in the surface water ranged from 3 .4 × 105 to 2.3 × 106 ml-1 in the investigated area. High abundance occurred in the shelf water and low abundance in the Kuroshio Current water. The horizontal distribution of this group of virioplankton correlated positively and most significantly with that of heterotrophic bacteria ( r = 0.85 , p < 0.01), then with that of Synechococcus (r = 0.65, p<0.01) and that of pico-eukaryotes ( r = 0.52, p<0.05), but negatively with that of Prochlorococcus (r = -0.60, p<0.01). Its distribution did not correlate with bulk chlorophyll a or size-fractionated chlorophyll a biomass. However, its vertical distribution correlated positively with those of the Prochlorococcus and Synechococcus, but not with those of pico-eukaryotes or bulk or size-fractionated chlorophyll a biomass. Possible explanations were discussed.