Quantitative and Qualitative Analysis of Plankton in the Paddy Fields of Imphal East District, Manipur

Abstract

Investigation on the seasonal distribution and abundance of various taxa of phyto- and zooplankton and their corresponding physico-chemical characteristics were carried out in four selected sampling sites between the latitude 25⁰5^/31.995^// N to 24⁰39^/45.25^// N and 94⁰8^/49.324^//E to 93⁰53^/47.559^//E Imphal East district. Drop count method was followed for the qualitative and quantitative analysis of both phyto and zooplankton. With about 500 phytoplankton are incredibly diverse and play a crucial role in paddy field ecosystem, they belong to different groups belonging 4 classes and 471 zooplankton genera were recorded. Zooplankton growth cycle was noticeably less than the phytoplankton abundance in the paddy fields during study period. During summer phytoplankton were recorded maximum as compare to zooplankton. Among phytoplanktonic groups, Cyanophyceae they perform photosynthesis and are crucial for nitrogen fixation was found to be dominating 16% in most of the sampling sites and followed by Bacillariophyceae (Silica cell wall) 13% during the investigation period. The pattern of differences of plankton standing crop in different sampling sites of paddy fields can be attributed to the existing physico-chemical characteristics mainly temperature, pH and hardness. Each genus has distinct adaptations for surviving in different aquatic environments. Phytoplankton is essential for supporting food web and influencing atmospheric oxygen of aquatic organism.