Abstract
During the last decades, we have witnessed a dramatic increase in the occurrence of algal blooms in the Baltic Sea. According to our current understanding, both bottom-up nutrient control and top-down grazing control govern phytoplankton development. However, while previous studies have investigated cyanobacteria-grazer interactions in the Baltic Sea, none has so far considered the possibility that zooplankton food selectivity may play a central role for the initiation and persistence of these blooms. Our aim is to study the ability of herbivorous zooplankton and mysid shrimps to induce and sustain toxic Nodularia blooms by selective grazing. The hypothesis is one of the first to consider food selectivity as a potential mechanism inducing and sustaining toxic blooms in the Baltic Sea. The research plan is a novel combination of modern and traditional approaches; it combines traditional experiments and field observations with cutting-edge PCR-based diet analysis, stable isotope analysis, RNA-based growth assessment, toxin measurements and long-term data analyses. Our results will shed new light on the relationship between zooplankton and toxic phytoplankton blooms, and they will broaden our understanding of toxic cyanobacteria bloom dynamics and importance of the cyanobacteria for zooplankton production. The current study is one step on the way towards a unified framework for understanding cyanobacteria role in the contemporary Baltic Sea.
Sweden