Population dynamics of Ramshagor of Dinajpur
BIODIVERSITY, ABUNDANCE OF PLANKTON AND WATER QUALITY VARIABLES OF RAMSHAGAR IN DINAJPUR
Ramshagar dighi is the largest man made pond (Dighi, Bengali meaning) sited at Tajpur village in Dinajpur. It bears some exceptional historical events of national heritage. The water area of Ramshagar dighi measures 1039m along north-south and 192.6m along east-west. Approximate depth of the tank is 9.10m Ramshagar dighi is surrounded by l0.75m high wall.
The study provides as overview of the physical, chemical, biological parameters and the biodiversity of a perennial, legendary, freshwater reservoir the Ramshagar dighi has been carried out for 11 months study period from May 2011 to March 2012.
The ranges of different physico-chemical characters of water of the Ramshagar dighi were: average monthly air temperature 24.97°C±4.92; water temperature 24.68°C+4.77; monthly average humidity 82.075 +4.14; total rainfall during the study period 1534.5 mm, average water depth 9.10 m±1.286 ; pH 7.67+0.48; DO 4.65±0.62 and CO2 0.85 ± 0.92.
The total of 48 species of phytoplankton belonging 36 genera has been recorded. Thirteen genera and 15 species belonged to Chlorophyceae, 10 genera and 10 species belonged to Cyanophyceae, 6 genera and 10 species belonged to Bacillariophyceae, 3 genera and 9 species belonged to Euglenophyceae, 3 genera and 3 species belonged to Dinophyceae and 1 genera and 1 species to Xanthophyceae. Chlorophyceae was found to be dominant group. The most phytoplankton was found in the month of July, 2011 and the less amount of phytoplankton was found during the month of March, 2012.
Zooplankton consists 27 species including 21 genera, of which 9 genera and 12 species belonged to Rotifera, 5 genera and 7 species belonged to Cladocera, 6 genera and 7 species belonged to Copepoda and a nauplius larva. The rotifera is the dominant group of these. The zooplankton were found peak in the month of June, 2011 and the less amount of zooplankton were found during the month of March, 2012.
The present paper is based on the biodiversity of Ramshagar dighi survey and also tries to explore the migratory birds in the study area. In 2001, Ramshagar dighi was declared National park by the authority. After this declaration, importance of Ramshagar dighi has been increasing sharply to the tourists. The purpose of the study was to provide up-to-date information on Ramshagar dighi. The fisheries biodiversity in the Ramshagar dighi comprised of 45 species have been identified. The Piscine fauna including 37 species belonging 26 genera and 12 families under 7 orders. The non-fin fisheries species comprised of 8 species belonging to Crustacean (2), Molluscan (6). The wild life and Migratory bird’s of Ramshagar dighi includes about 33 species belonging to 24 families and 16 orders were recorded from the study area (Ramshagar dighi). Among these, 1 order, 1 family, and 2 species belonging to Amphibian, 2 orders, 3 families, and 4 species belonging to Reptilian, 11 orders, 15 families and 21 species belonging to Avian fauna, Among the Avian fauna, 3 orders, 3 families and 7 species belonging to Migratory bird and 2 orders, 5 families and 6 species belonging to mammalian fauna.