In this post, Trong Dieu Hien Le talks about her recently published paper “Invertebrate turnover along gradients of anthropogenic salinization in rivers of two German regions”.
Rising salinity in freshwater ecosystems can affect community composition. Recent studies have identified geological and climatic conditions as the main natural drivers of rising conductivity (EC) in Central European and Northern American surface waters. These studies allow estimation of EC in a site determined by natural processes (also called background EC) without human influence. Hence, the difference between the estimated background EC and the observed EC in a site (EC change) can serve as a proxy of human influence on water community composition due to an increase in EC.
For this research, two datasets were used to examine the turnover in freshwater invertebrates due to EC change. This change was driven by humans in two regions of Germany (North Rhine-Westphalia and Thuringia).
A maximum of about 70 % change was observed in the invertebrate community following changes in EC. An EC change of more than 0.4 mS cm−1 in these regions was found to affect invertebrate community.
Additionally, the invertebrates Amphinemura sp., Anomalopterygella chauviniana, and Leuctra sp. were reliable indicators of low EC change. On the other hand, Potamopyrgus antipodarum indicated sites with the highest EC.