Will the Buildup of Anthropogenic CO 2 in the Atmosphere Intensify Estuarine Eutrophication?

1. Will the Buildup of Anthropogenic CO2 in the Atmosphere Intensify Estuarine Eutrophication? • We conducted experiments to test the hypothesis: CO2 enrichment (to predicted Year 2100 levels) will stimulate phytoplankton growth and productivity in eutrophying estuaries, in this case Apalachicola Bay. • A small ,but significant increase in phytoplankton biomass was noted in response to CO2 amendments, but only in nutrient-enriched (i.e., simulating eutrophication) treatments. • Results suggest that phytoplankton response may differ depending on location along estuarine salinity gradient. Example response of estuarine phytoplankton to modern & future predicted CO2, nutrient levels. Both future nutrient treatments were significantly different than modern nutrient treatments, and future nutrient & CO2 treatment was significantly different than future nutrient & modern CO2 treatment. • Future Work: • Conduct experiments seasonally & at various locations along salinity gradient. • Compare response of phytoplankton in high vs. low alkalinity rivers (some estuaries are better buffered against CO2 changes). Michael S. WetzFlorida State University Department of Oceanography mwetz@fsu.edu