Global change and plankton ecology in Atlantic South America

Abstract

In aquatic ecosystems, global change encompasses human-induced variations in the upper layer of the water column, where most of carbon fixation takes place. These changes include increments of exposure to solar UV radiation, mean temperature of surface seawater, ocean acidification and nutrient concentrations. These factors are well known to affect plankton ecosystems, although not all organisms are equally affected. In addition, many times these factors interact and the final results are not always additive or synergistic as expected. Finally, indirect effects (e.g., through trophic interactions) are often more pronounced than direct ones (e.g., survival or growth), which tend in some cases to mask overall and long-term expected ecological shifts in plankton communities.We review the main contributions in this field from the Atlantic coast of South America and discuss in a final section what have we learned and what is still unknown as global changes seems to be here to stay.