Ecology, Environment and Conservation Paper

MARINE PICOPHYTOPLANKTONS IN THE WORLD OCEANS - A REVIEW

Pratyush Das, R.K. Mishra, A.K. Bhargava, Sarmistha Mishra and P.K. Mohanty

Abstract

The Picophytoplankton Prochlorococcus marinus, are abundant and wide spread throughout the world oceans and shares its niche with Synechococcus and picoeukaryotic (PEUK) geographically. We analyzed these ubiquitous members of marine phytoplanktons at surface water of the world oceans with an overview of its presence under various environmental factors like temperature and salinity. An attempt is made to analyze the mean presence of these phytoplanktons in certain oceans and seas constituting in the world oceans. During summer, mean abundances of Prochlorococcus were found to be high in Pacific Ocean with cell concentrations of 17472.33×105 cellsml-1 at mean temperature and salinity of 21.5oC and 30 psu. Low mean abundance of Prochlorococcus was encountered in Arabian Sea with cell concentrations of 0.54×105 cellsml-1. Mean abundances of Synechococcus was found to be maximum in Arctic Sea with cell concentrations of 1126×105 cellsml-1 at mean temperature and salinity of 8.25oC and 32.76 psu. Low mean abundance of Synechococcus was found in Atlantic Ocean with cell concentration of 0.010393×105 cells ml-1. In other hand, PEUK, mean maximum abundance was encountered in Arctic Sea with cell concentrations of 1466×105 cellsml-1 with temperature and salinity of 8.25ˆC and 32.76 psu. Low abundance was found in Arabian Sea with cell concentration of 0.37×105 cellsml-1. However in winter, mean abundances of Prochlorococcus and Synechococcucs was found to be maximum in Southern Ocean with cell concentration of ˆ 1×105 cellsml-1 and 8×105 cells ml-1 respectively with average temperature and salinity of 8.10ˆ C and 35.40 psu. In PEUK, mean maximum abundance was encountered in Southern Ocean with cell concentrations of 1.1505×105 cellsml-1 under same temperature and salinity. Mean low abundances of Prochlorococcus were found in Cantrabian Sea with cell concentration of 0.5075×105 cellsml-1 with average temperature and salinity of 16.98ˆ C and 35.49 psu, while Synechococcus was found in Arctic Sea with cell concentration of ≤ 0.00023×105 cellsml-1 at mean temperature and salinity of -6.5 oC and 34.53psu and mean low abundances PEUK were found in Arctic Sea with cell concentration of 0.0055×105 cellsml-1 under same temperature and salinity. The result shows the picophytoplanktons flourishes maximum in the world oceans at average temperature and salinity of ≥ 80C and ≥ 32.6 psu, contributing their highest contribution of primary production.