North Atlantic Oscillation synchronizes food-web interactions in central European lakes

Abstract

A regular and distinct feature of seasonal plankton succession in temperate lakes is the early summer period of algal suppression by herbivores, i.e. the clearwater phase. Within the last 30 years the timing of this food–web interaction between algae and herbivores has advanced on average by approximately two weeks in central European lakes due to faster population growth of herbivores in warmer water. Trend and interannual variability in clearwater timing were strongly related to the climate dynamics of the North Atlantic, i.e. the North Atlantic Oscillation (NAO). Due to its large–scale effects, the NAO synchronized plankton succession in central European lakes, causing a striking temporal coherence of a food–web interaction over several hundreds of kilometres.