Nutrients in sediment regulate benthic algal assemblages in the tropical Tri An reservoir of Vietnam

Abstract

: Benthic algal assemblages are considered effective indicators of environmental change because they sensitively respond to a variety of environmental conditions. This study aims to investigate the relationship between the benthic algal community and nutrient variables in sediment using Spearman’s correlation and linear regression analysis. A total of 27 genera of benthic algae were recorded during the study period where cyanobacteria and diatom were the two dominant groups. Several species belonging to Achnanthidium, Luticola, Lyngbya, Navicula , and Phormidium sensitively responded to nutrient levels and were used as bioindicators . Multiple stepwise linear regression revealed that ammonium (NH 4+ ) and total nitrogen (TN) positively correlated with several indices of the benthic algae assemblage. This preliminary data set demonstrates the use of benthic algae as precise biological indicators for a measure of the ecological integrity of an aquatic ecosystem and contributes to the further study of benthic environments in tropical regions.