STUDY ON LIMNOLOGICAL ASPECTS OF ASHURA BEEL IN DINAJPUR DISTRICT

Abstract

An investigation was carried out on the limnological aspects of Ashura beel of Dinajpur district in Bangladesh. In this study, several limnological parameters were evaluated from March 2013 to October 2013 from three sampling sites namely Kajladoho, Burirdoho and Sonnasydoho. Physical, chemical and biological parameters were analyzed fortnightly both at the field level and laboratory of Fisheries Management, Faculty of Fisheries, Hajee Mohammad Danesh Science and Technology University, Dinajpur. In the study area the varied ranges of air temperature (19.00 to 36.10°C), water temperature (24 to 35.50°C), transparency (17 to 27.50 cm), water depth (0.58 to 2.44 m), dissolved oxygen (5.90 to 7.83 mg/L), pH (6.10 to 8.50), total alkalinity (72 to146 mg/L), total hardness (150 to 247 mg/L), phosphate-phosphorus (0.50 to 0.90 mg/L), plankton density (2.73 to 9.88x10° cells/L) and concentration of chlorophyll-a (11.90 to 47.60 pg/L) were found. Thirty four species were recorded where phytoplankton includes 29 species belonging 4 groups such as euglenophyceae, cyanophyceae, bacillariophyceae and chlorophyceae and five species of zooplankton namely copepoda, rotifera, cladocera and crustacea. Phytoplankton was dominated by chlorophyceae and zooplankton dominated by copepods. Dissolved oxygen showed significant direct relationship with plankton but inversely related with water temperature. Positive relationships were also observed among pH, alkalinity and total hardness. However, from the findings of this study it is clear that the water quality parameters of the beel water found to be suitable for the growth and survival of aquatic organism.