Sensitivity of Marine Phytoplankton to Uv‐b Radiation: Impact Upon a Model Ecosystem

Human activities may cause a 16% reduction of stratospheric ozone. The concomitant increase in solar UV‐B radiation reaching the surface of the earth could detrimentally affect the phytoplankton that form the base of the food web in oceanic and estuarine ecosystems. In the current study acute exposure of seven species of marine phytoplankton to UV–B radiation depressed the radiocarbon estimate of primary production. A model of a marine ecosystem was constructed based on the differential sensitivities of the seven species of phytoplankton. Increasing the UV–B exposure within the model from 100 EffDNAJ/m2/day to 150 EffDNAJ/m2/day significantly altered the community composition of the ecosystem. In nature, alteration of the phytoplanktonic community structure could result in a significant impact upon successional patterns and primary producer–consumer trophodynamics.