In a 101 days-long mesocosm experiment, the mechanistic functions and interactions of seagrass-bivalve communities were investigated. The treatment communities consisted of all possible combinations (full-factorial design) of the three study organisms, the seagrass Zostera marina, the commonly associated epifaunal bivalve Mytilus trossulus, and the infaunal bivalve Macoma balthica, at natural densities. The study aimed to investigate the impacts of these communities on (i) water column and pore water nutrient (ammonium, nitrate, nitrite, phosphate) concentrations, (ii) on seagrass performance following one growing season (over time: shoot density, total leaf length, growth rate; at the end of the experiment: dry weight and above – below ground biomass ratio), and (iii) on the performance of the two bivalve species (survival, wet weight gain). Additionally, (iv) the epiphyte pressure in the experimental communities was analysed.
