Seasonality and diversity of epipelic diatoms in two wetlands of Banglades

Abstract

Seasonality and composition of epipelic diatom community were studied for two years in two wetlands of Bangladesh namely, Joysagar and Sitlai Beel. A total 73 diatom taxa were recorded. The average density of epipelic diatom was higher in Sitlai Beel (52.97  10 4 /g sediment) than in the Joysagar (3.92 10 4 /g sediment). The epipelic diatom community of Joysagar was dominated by the species of Melosira, Synedra, Navicula, Pinnularia, Gomphonema, and Nitzschia, whereas Melosira, Navicula, Pinnularia, Cymbella and Gomphonema dominated in Sitlai Beel. Melosira granulata, Navicula americana, Pinnularia major, and Gomphonema lanceolatum were dominant and expressed distinct seasonality in both wetlands. The concentration of soluble reactive silicate of water and the average density of epipelic diatom did not express any significant relation in both of the water bodies. The concentration of phytoplankton chl a had a positive relationship with epipelic diatoms and was significant in Sitlai Beel.

Limnological Notes on Ramsagar, Dinajpur, Bangladesh

“…The basin of Ramsagar was dug out by the King Ramnath of Dinajpur between 1750 and 1755 AD. Nahar and Khondker (2009) and Nahar et al (2010) studied the epipelic diatom and their relationships with the limnological parameters of Jaysagar. Aziz and Tanbir (2003) studied a few phytoplankton of Ramsagar.…”

Newly Recorded Freshwater Diatioms (Bacillariophyceae) From Two Wetlands of District Sirajganj, Bangladesh

“…The ecology of epipelic diatoms are less well studied than their pelagic counterparts in various limnological studies in Bangladesh, except the work of Sultana et al (2003). The seasonality and diversity of sediment diatoms and some of their taxonomic descriptions from two wetlands Joysagar and Sitlai Beel of Sirajganj, northern part of Bangladesh have been studied by Khondker 2009 andNahar et al 2010. The present report on diatoms is a continuation of epipelons analysis of same areas i.e.…”

Limnological notes on Nilsagar, Nilphamari, Bangladesh

“…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.…”

“…Khondker et al (1) studied the water quality and phytoplankton community of Ramsagar. Nahar and Khondker (2) and Nahar et al (3) studied the epipelic diatom and their relationships with the limnological parameters of Jaysagar. Aziz and Tanbir (4) studied a few plankton of Nilsagar.…”

“…Nitrate-nitrogen concentration was remarkably low and showed 0.19 mg/l ( Table 2). The water quality data of Nilsagar has been compared with those of Ramsagar (1) and Joysagar (3) (Table 2) and it has been seen that the mean alkalinity of water is almost same in all three water bodies. Mean pH value was almost similar in Nilsagar and Ramsagar.…”