Sediment distribution pattern and environmental implications of physico-chemical characteristics of the Akkulam-Veli Lake, South India

Abstract

This study reports the spatial distributions of diatom assemblages and potential relationships between diatom diversity and environmental variables (C/N ratio, CaCO 3 %, clay mineralogy) using multivariate analyses in surface sediments of the Akkulam-Veli Lake. Surface sediment samples were collected at 19 sites throughout the lake to analyse diatom distribution, TOC, N, CaCO 3 %, clay mineralogy and sediment texture. The results suggest that the clay fraction is predominant in the eastern flank, whereas sand fraction is more in the western flank. TOC% and CaCO 3 % in the lake floor sediments are attributed to high organic activity within the lake and contributions from the vegetation around the lake margins. The results suggest that N is being added to the lake from secondary sources from catchment area leading to eutrophication of the lake. Further, clay mineralogy of the sediment samples reveals that kaolinite mineralogy dominates in clay fractions. Diatom studies show rich diversity of freshwater, marine and brackish diatoms and abundance of pollution-reflecting species such as Cyclotella sp. and Navicula sp.

Bottom Sediment Characteristics of a Tropical Lake: Lake Tana, Ethiopia

“…The kriged maps in Figure 5 show that the sand and silt fractions were the greatest near the outlet of the lake (Figure 5a,b) where the Blue Nile starts. One sampling point (13) near the Gilgel Abay had the greatest sand content (68% , Table A1). Silt content was also elevated near Rib and Gumara rivers on the east side of the lake (station 48) and Rib inlet (station 58).…”

“…Research on the spatial distribution of bottom sediment characteristics aids in lake management strategies. To do so, previous studies have determined: the spatial distribution pattern to understand sedimentation conditions in Lake Abaya and Chamo, Ethiopia [12] and Kodaikanal and Akkulam-Veli Lake, India [9,10,13]; the source of the organic matter deposition in Lake Victoria [14], Lake Kodaikanal,…”

Experimental analysis of particle size distribution using electromagnetic sieves shaker

“…Sieve analysis was done in the laboratory of Department of Environmental Sciences & Limnology, during the study. Several authors have studied the textural characteristics of sediments from different rivers of the India as well as [10][11][12][13][14][15][16][17][18] .…”