Seawater carbonate chemistry and antagonistic effects of three strains of the dinoflagellate HAB species Alexandrium catenella on three target species

We tested the antagonistic effects of three strains of the dinoflagellate HAB species Alexandrium catenella on three target species (the chlorophyte Tetraselmis sp., the cryptomonad Rhodomonas salina, and the diatom Thalassiosira weissflogii) at various biomass ratios between species, at ambient (16 ◦C and 400 μatm CO2) and OWA (20 ◦C and 2000 μatm CO2) conditions. In these experiments the Alexandrium strains had been raised under OWA conditions for ~100 generations. All three non-HAB species increased their growth rate under OWA relative to ambient conditions.