胶州湾叶绿素a浓度及浮游植物的粒级组成

2008年2、5、8和11月对胶州湾及邻近水域中表层叶绿素a浓度和浮游植物粒级组成进行了调查.结果表明:胶州湾内和湾外表层叶绿素a年平均浓度分别为4.90和2.03 mg·m^-3；叶绿素a浓度的平面分布呈现自东北部及近岸向中部、南部及湾外递减的趋势；叶绿素a浓度季节变化明显,冬季和夏季浓度较高,春季次之,呈现温带海域双峰型的变化趋势.胶州湾浮游植物粒级组成以微型浮游植物为主,平均占叶绿素a总量的60.9%,其次是小型浮游植物,超微型浮游植物所占比例最低,与我国近海浮游植物粒级组成基本一致.与历史资料相比,微型浮游植物所占比例有所增加,超微型浮游植物所占比例降低.

Chlorophyll-a concentration and phytoplankton size-fractionated composition in Jiaozhou Bay

An investigation was made on the chlorophyll-a (Chla) concentration and phytoplankton size-fractionated composition in Jiaozhou Bay and its adjacent waters in February, May, August, and November 2008. The average annual Chla concentrations inside and outside the Bay was 4.90 mg·m^-3 and 2.03 mg·m^-3, respectively. The Chla concentration presented a decreasing trend from the northeast and near-shore to the central, south, and outside of the Bay, and had an obvious double-peak seasonal variation, being higher in summer and winter. The phytoplankton in the Bay was dominated by nanophytoplankton, accounting for 60.9% of the total Chla concentration, followed by microphytoplankton, and picophytoplankton, which was consistent with the phytoplankton size-fractionated composition in coastal waters of China. Comparing with historical data, the proportion of nanophytoplankton in the Bay had some increase, while that of picophytoplankton decreased to some extent.