Relationships between algae taxa and physico-chemical characteristics of water in wetlands and waterbodies

Abstract

A study of algae flora was performed on 16 samples collected in different aquatic environments in Bamenda (Cameroon) in order to evidence the relationships between algae assemblages and physico-chemical parameters of the milieu. A total of 22 algae species were identified, the most represented class being Bacillariophyceae (8 species), followed by the Cyanophyceae (5 species), Zygnemataceae (4 species), Euglenophyceae (3 species) and finally Chlorophyceae (2 species). Physicochemical analyses of water samples suggest evidences of organic pollution related to anthropogenic activities, running waters being less affected than stagnant ones. This organic pollution is inferred from highest values of TDS and conductivity. The Correspondence Analysis (CA) displayed four groups of algae on the two first axes. On axis 1 the discriminating factor is the current, because running water sites are opposed to stagnant water ones. Unfortunately measured values of water current are not available to precise that hypothesis, our interpretations in this paper are based on relative data. The second axis reveals the opposition between oligotrophic and eutrophic waters, and could be considered as a gradient of organic pollution. The species Navicula sp, Gomphonema sp, Ulothrix sp., Nostoc sp., Amphora sp., Pinnularia sp., Tabellaria sp. and Lyngbya sp. are associated to low values of TDS and conductivity while Phacus sp., Closterium sp., Euglena sp. and Trachelomonas sp. thrive better in high polluted waters. The distribution of these algae identified as indicators of high organic pollution, evidenced a spatial variability of organic pollution in accordance with the water physicochemical parameters monitored. This variability is probably modulated by the presence in the sampling sites of macrophytes that are efficient in removing pollutants.

Keywords: Bamenda, algae, correspondence analyse, organic pollution, phytoremediation

CaJEB Vol. 3 (2) 2007: pp. 70-79