Comparative analysis of bacterioplankton and phytoplankton in three ecological provinces of the northern South China Sea

Abstract

The association between heterotrophic bacterioplankton and phytoplankton was examined in the northern region of the South China Sea where 3 marine biogeochemical provinces adjoin. The relationship between bacterial abundance and total chlorophyll a concentration was significant in the oceanic Archipelagic Deep Basin Province and in the China Sea Coastal Province, but not so in the Beibu Gulf (Sunda-Arafura Shelves Province), The importance of different phytoplankton groups (netplankton, nanoplankton and picoplankton, Synechococcus spp., Prochlorococcus spp. and picoeukaryotes) to bacteria was examined by multiple linear regression analysis. We found that bottom-up control on bacteria depended strongly on the picoplankton size class of the phytoplankton, and particularly on the picocyanobacteria Synechococcus spp. Possible carbon transfer mechanisms suggest a plausible basis for the linkage of Synechococcus spp. to bacteria. © Inter-Research 2005.