Advances in ecological research of Pearl River Estuarine bacterioplankton

Abstract:

Estuarine ecosystems are characterized by extreme variations of salinity and nutrients. In such ecosystems, mechanisms of matter cycling are highly complex. Apart from the influences of fresh and marine water, and interaction between land and ocean, bacterioplankton also plays an important role in the matter cycling in estuarine aquatic ecosystems. Studies on bacterioplankton are, therefore, considered important for the understanding of matter cycling in the subtropical estuary such as that of the Pearl River Estuary. Previous studies in Pearl River Estuary show that the most dominant bacterioplankton groups were Proteobacteria and Cyanobacteria. While the bacterial community structure and abundance were influenced by salinity, temperature and nutrient concentration, their productions and abundance were limited by virus and flagellate, and there was positive relationship between bacterial biomass and phytoplankton. However, there were no comprehensive studies about function and cycle of earth matter of bacteria in Pearl River Estuary. Knowledge gaps still exist about mechanism for transformation of organic matter driven by microorganism and the corresponding ecological significance in this region. This review covers studies on estuarine bacterioplankton species composition, distribution, biomass, matter cycling and other relative environmental factors. Additionally, this article provides a future framework for Pearl River Estuary aquatic ecological system.