Water residence time and the dynamics of toxic cyanobacteria

SUMMARY 1. Climate change affects aquatic ecosystems differently depending on local conditions. In the Mediterranean region, predicted drier seasons could especially affect lake water residence time and in consequence cyanobacteria and cyanotoxin dynamics. 2. We carried out a 3-year study of a shallow, Mediterranean lake (Lake Albufera, Spain), to study the effects of water residence time and other drivers on the dynamics of harmful cyanobacteria and microcystin concentrations (MCYST). 3. Longer water residence time in dry years and dry seasons increased total cyanobacteria biomass, Microcystis aeruginosa populations and MCYST concentrations in the lake water and seston. Droughts increased …