EFFECTS OF WATER PARAMETERS ON PHYTOPLANKTON ABUNDANCE IN PANGASIUS Pangasianodon hypophthalmus AND TILAPIA Oreochromis niloticus PRODUCTION

Sultan Mahmud*, Seikh Razibul Islam, Md. Emranul Ahsan, Niels O. G. Jørgensen, Muhammad Abdur Razzak, Md. Yusuf Ali
Department of Aquaculture
Faculty of Fisheries
Patuakhali Science and Technology University, Patuakhali-8602, Bangladesh
sultanmahmud77@yahoo.com
 

Phytoplankton and zooplankton retort rapidly to any alterations in nutrient changes in water bodies indicating the growing nutrient pollution. Plankton analysis gives an overview of the environmental condition of the water body. On one hand where phytoplankton serves as food source, on the other hand some forms causes fish poisoning due to release of toxins during blooms (Boyd, 2004). The present study was carried out to analyze the water quality and plankton diversity of 4 selected pangasius (Pangasianodon hypophthalmus) and tilapia (Oreochromis niloticus) ponds from two different regions of Bangladesh; Bogra and Khulna.

Monthly sampling was done for a period of 12 months, July 2016 to June 2017. Samples were collected from one pangasius pond and one tilapia pond from each region in triplicate. Samples were analyzed for physico-chemical parameters. Quantitative analysis of plankton was done on Sedgewick-Rafter counting chamber (S-R cell). Qualitative study of plankton was done to identify plankton up to genus level.

Plankton populations in the water of the experimental ponds were found to be consisted of 91 genera belonging 94 species under 13 planktonic groups composed of 9 groups of phytoplankton and 4 groups of zooplankton (Table 1).

Carl Pearson's correlation coefficients were calculated for abundance with different water parameters. Temperature, nitrate, phosphate, ammonia were positively correlated and pH, DO, transparency were negatively correlated with the plankton abundance.

Results shows that the water is fairly good for fish culture. Nutrients of water enhanced the plankton growth which can lead to bloom. Therefore, it needs some corrective measures to maintain the water chemistry of the pond which will help to keep the plankton community in control.