PHYTOPLANKTON COMMUNITY OF JIAOZHOU BAY IN WINTER 2010

We studied the characteristics of phytoplankton community based on phytoplankton data from 23 grid stations in the Jiaozhou Bay in winter 2010. Five classes including 44 genera and 69 species were identified. The average cell abundance was 222.8 ind./m L. The abundance and distribution of diatoms reflected the overall variation of phytoplankton. The dominant species were Guinardia delicatula, Chaetoceros tortissimus, Thalassiosira nordenskildii, and Pseudo-nitzschia pungens. The phytoplankton cell abundance was higher in the northern section and lower in the southern in horizontal distribution, and no significant difference from surface layer to the bottom in vertical distribution. The horizontal distribution of phytoplankton Shannon-Wiener index varied greatly from 0.497 to 3.404 in average of 2.335, high in the mouth area and low in the northwestern section due probably to the impact of sea ice. The Pielou index ranged 0.150—0.831 in average of 0.600, which is quite high in overall, high in the southeastern section and the mouth and low in the northwestern. Therefore, the phytoplanktonic community structure was comparatively even and stable in the deep area but near-coast shallow area. In addition, the phytoplankton cell abundance correlated positively to the ammonia, nitrate, nitrite, and silicate.