Lake salinization drives consistent losses of zooplankton abundance and diversity across coordinated mesocosm experiments

Human-induced salinization increasingly threatens inland waters; yet we know little about the multifaceted response of lake communities to salt contamination. By conducting a coordinated mesocosm experiment across 16 sites in North America and Europe, quantified zooplankton abundance (taxonomic functional) community structure broad gradient environmentally relevant chloride concentrations, ranging from 4 ca. 1400 mg Cl? L?1. We found that crustaceans were distinctly more sensitive elevated than rotifers; yet, rotifers did not show compensatory increases crustacean declines. For crustaceans, our among-site comparisons indicate: (1) highly consistent decreases taxon richness with salinity; (2) widespread sensitivity major taxonomic groups (Cladocera, Cyclopoida, Calanoida); (3) weaker loss functional diversity. Overall, study demonstrates aggregate properties can be adversely affected at concentrations anthropogenic lakes.