## 3 Results
### Bacteria in the Seawater  
Figure 6 describes the fluctuations of bacteria at Stn. 1, presenting the total number (direct count (DC)), free-living bacteria (DC of FLB, the \(<\)3 \(\upmu\)m fraction), particle-associated bacteria (DC of PAB, the \(>\)3 \(\upmu\)m fraction), the culturable bacteria (viable count (VC)), and their proportions (%) to the total number. The total counts (DC) of bacteria ranged from 5.4 \(\times\) 10\({}^{5}\) to 3.0 \(\times\) 10\({}^{6}\) cells mL\({}^{-1}\) (Figure 6a). The lowest value was recorded on 2 June, and the highest value was recorded on June 8.  
The densities of FLB were between 3.9 \(\times\) 10\({}^{5}\) and 1.5 \(\times\) 10\({}^{6}\) cells mL\({}^{-1}\). The numbers of PAB were 6.1 \(\times\) 10\({}^{4}\)-1.6 \(\times\) 10\({}^{6}\) cells mL\({}^{-1}\). The densities of FLB exceeded those of PAB in nine of the 11 surveys (the exceptions were the May 18 and June 8 surveys). Concerning the numbers of culturable bacteria at Stn. 1 for FLB and PAB, the densities of FLB were 8.8 \(\times\) 10\({}^{2}\)-2.0 \(\times\) 10\({}^{4}\) CFU mL\({}^{-1}\) and those of PAB were 4.0 \(\times\) 10\({}^{1}\)-3.7 \(\times\) 10\({}^{3}\) CFU mL\({}^{-1}\), showing wide fluctuations (Figure 6b). FLB exceeded PAB in 10 surveys (the exception was 2 June). The proportion of culturable bacteria to the total bacteria showed relatively low values of 0.11-1.93% for FLB and 0.01-1.37% for PAB (Figure 6c).  
Figure 7 shows the densities of bacteria in the surface waters at Stn. 2. The total counts (DC) of bacteria ranged from 3.9 \(\times\) 10\({}^{5}\) to 1.9 \(\times\) 10\({}^{6}\) cells mL\({}^{-1}\) (Figure 7a). The direct counts of FLB were between 3.8-8.0 \(\times\) 10\({}^{5}\) cells mL\({}^{-1}\), and those of PAB were 5.1 \(\times\) 10\({}^{3}\)-1.1 \(\times\) 10\({}^{6}\) cells mL\({}^{-1}\). In particular, the PAB densities were characterized by low values after June. The density of PAB exceeded the density of FLB only once, on 18 May. Concerning the numbers of culturable bacteria (VC), the FLB densities were 1.0 \(\times\) 10\({}^{2}\)-1.3 \(\times\) 10\({}^{4}\) CFU mL\({}^{-1}\) and the PAB densities were 2.1 \(\times\) 10\({}^{2}\)-6.5 \(\times\) 10\({}^{3}\) CFU mL\({}^{-1}\) (Figure 7b). The FLB fraction of the culturable bacteria tended to be higher in density than PAB. The proportion of viable bacteria to the total number of bacteria was 0.03-2.18% in FLB and 0.19-22.91% in PAB (Figure 7c).  
Figure 6: Bacterial numbers in the seawater samples from Stn. 1 (0 m): the direct counts (**a**), the viable counts (CFU) (**b**), and the percentages of viable counts to direct counts (**c**).  
Figure 8 presents the surface seawater results from the offshore point of Stn. 3. The total counts of bacteria were very stable, showing values in the narrow range of 2.3-4.1 \(\times\) 10\({}^{5}\) cells mL\({}^{-1}\) (Figure 8a). The direct counts of FLB were 1.8-2.9 \(\times\) 10\({}^{5}\) cells mL\({}^{-1}\) and that counts of PAB were 2.4 \(\times\) 10\({}^{4}\)-2.2 \(\times\) 10\({}^{5}\) cells mL\({}^{-1}\), respectively. FLB showed higher densities except on 6 May. Regarding the numbers of culturable bacteria, those of FLB were 2.8 \(\times\) 10\({}^{2}\)-5.1 \(\times\) 10\({}^{3}\) CFU mL\({}^{-1}\), and those of PAB were 8.0 \(\times\) 10\({}^{1}\)-3.8 \(\times\) 10\({}^{3}\) CFU mL\({}^{-1}\). The values at Stn. 3 were generally lower than those at the other two stations (Figure 8b). The percentages of culturable bacteria to the direct counts of bacteria were 0.12-2.17% for FLB and 0.13-8.35% for PAB. The PAB fractions were higher than the FLB fractions (Figure 8c).  
Figure 7: Bacterial numbers in the surface seawater samples from Stn. 2: the direct counts (**a**), the viable counts (CFU) (**b**), and the percentages of viable counts to direct counts (**c**).