ABSTRACT

The distribution and ecology of autotrophic pico- and nanoplankton were studied in the warm core eddy-affected northern Bay of Bengal (BoB) during the peak south-west monsoon of 2012. Small phototrophs showed diverse response patterns to the contrasting environmental setting in the northern BoB during the south-west monsoon. The convergence of surface waters in the eddy-influenced region was evidenced in terms of a deeper mixed layer and lower concentrations of $\mathrm{N}{\mathrm{O}}_3^{-}$. Synechococcus and picoeukaryotes were found to be more abundant in coastal waters as compared with the warm core eddy-influenced and offshore waters. Prochlorococcus was more abundant in the eddy-influenced and the offshore regions possibly as a consequence of their ability to survive in low-nutrient/oligotrophic waters. The abundance of Synechococcus increased noticeably in the coastal and subsurface waters due to their affinity towards higher concentrations of nutrients. The present data therefore support the view of a community shift induced by warm core water eddies and show their importance in promoting primary production by Prochlorococcus in the mixed layers of the BoB.

摘要

在2012年西南季风高峰期间，在受暖涡涡影响的孟加拉北部北部湾（BoB）上研究了自养微微和纳米级浮游生物的分布和生态学。小型自养生物显示出对北部北部不同环境设置的不同响应模式BoB在西南季风期间。涡流影响区地表水的汇聚表现为混合层更深，浓度较低。$\mathrm{ñ}{\mathrm{Ø}}_3^{-}$。与温暖的核心涡流和近岸水域相比，沿海水域中的球菌和微核生物的含量更高。原球菌在受到涡流影响的地区和近海地区更为丰富，这可能是由于它们能够在低营养/贫营养水域中生存。在沿海和地下水域中，由于球菌对高浓度养分的亲和力，其球菌的丰度显着增加。因此，目前的数据支持了由温暖的核心水涡引起的群落转移的观点，并显示了它们在促进BoB混合层中原球菌的初级生产中的重要性。