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 (NH₄⁺) 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.