Application of Biolog Ecoplate™ Technique for Assessing the Effects of Macrophyte Harvesting on Aquatic Bacterial Communities

Abstract

Macrophyte overgrowth in freshwater ecosystems is a worldwide problem, and a common management practice for these ecosystems is to remove the aquatic vegetation. In the study, the short-term effects of macrophyte harvesting in a mountain lake (Trevnoto Lake, Bulgaria) on both bacterial metabolic activity and fingerprints were assessed using Biolog Ecoplate™ assay. Bacterial responses to human activity were manifested by: 1) increased bacterial metabolic activity by 15%, and 2) shifts in bacterial metabolic fingerprints. The most affected carbon sources were those with low availability for aquatic bacteria – 85% of them were influenced and the rates of their utilizations changed from a decrease of 96% to an increase of 681%. In general, a clear trend was formed that the greater the bioavailability of the carbon sources, the less susceptible is their utilization to the environmental change. This preliminary study indicates an immediate impact of macrophyte harvesting on lake bacteria. In this aspect, Biolog Ecoplate™ assay could be useful in lake monitoring programmes in order to develop better sustainable management practices for restoration.