Limnological Notes on Ramsagar, Dinajpur, Bangladesh

Abstract

Ramsagar, an artificial lake of Dinajpur district has been investigated limnologically. Mean alkalinity, DO, pH, TDS and conductivity of the lake were 0.50 meq/l, 7.99 mg/l, 6.73, 10.66 mg/l and 73.66 ?S/cm, respectively. The concentration of soluble reactive phosphorus and silicate was very low. Mean value of the former parameter was 3.16 ?g/l and the latter was 0.77 mg/l. Nitrate-nitrogen concentration was < 0.1 mg/l. Phytoplankton biomass as chl a was 5.92 ?g/l and that of phaeopigment 3.65 ?g/l. Phytoplankton flora of the lake was found to be dominated by desmids. The dominant species were Staurastrum coarctatum var. subcurtum (59.35×104, ind/l); S. subgracillimum var. tortum (44.83×104 ind/l) and S. leptacanthum (29.06×104 ind/l). Among the blue-green algae, Anabaena utermöhlii was dominant. Chlorococcales was represented by seven species. The total density of phytoplankton was 163.53×104 ind/l. Considering the overall limnological characteristics, the lake could be characterized as acidic and nutrient poor.DOI: http://dx.doi.org/10.3329/bjb.v41i1.11091 Bangladesh J. Bot. 41(1): 119-121, 2012 (June)

A study on limnological aspects of Ramsagar lake in Dinajpur district

“…Water pH was found mostly alkaline in point 3 during July and the lowest value was recorded in January in point 2. However, Khondker et al (2012) recorded pH value of Ramsagar 6.71 to 6.75 based on the analysis of a single sampling. According to Swingle (1967) pH value 6.5 to 9.0 is suitable for fish culture and more than 9.0 is unsuitable because free CO 2 is not available in this situation.…”

“…However, very few comprehensive works have been done on the limnological aspects Ramsagar lake in Dinajpur district (Aziz and Tanbir, 2003;Khondker et al, 2012). Researchers only concerned on the planktonic community of Ramsagar lake.…”

“…In the recent years environmental scientists of the country are interested to study the limnological status of surface water bodies to assess the water quality and biodiversity for conservation planning of the wetlands (Mohuya et al 2010;Hossain et al, 2010;Khondker et al 2012;Islam and Chowdhury, 2013 etc.). Contamination of Dhanmondi and Gulshan lake waters was studied by Hossain et al (2010).…”

Limnological notes on Nilsagar, Nilphamari, Bangladesh

“…During the British India rule a number of large sized ponds or man-made lakes were dug out by different Zamindars of that time to serve the needs of freshwater supply to the common people. Such water bodies of this category are still existing helter and skelter in different districts of Bangladesh (1) . Preliminary limnological information together with the diversity of phytoplankton and epipelic algae have already been carried out in some of those (1,2,3) .…”

“…Such water bodies of this category are still existing helter and skelter in different districts of Bangladesh (1) . Preliminary limnological information together with the diversity of phytoplankton and epipelic algae have already been carried out in some of those (1,2,3) . Nilsagar of Nilphamari district is one of the famous man-made lakes of Bangladesh.…”