Effects of Ocean Acidification on a Turtle Grass Meadow marielle battistoni ‘11, KatHerine fitZgerald ‘11, and suZanne

40 With increasing atmospheric CO2 concentrations, the oceans are expected to increase in acidity during the next century. Increasing ocean acidity has been shown to negatively affect many marine ecosystems, particularly calcifying organisms. We investigated acidification effects on the turtle grass communities of Little Cayman Island, British West Indies (BWI). We hypothesized that acidified seawater would decrease turtle grass growth, the presence of calcifying epiphytic algae, and the metabolism of snail grazers. We placed turtle grass and snails in tanks with acidified or natural seawater for four days. We found that turtle grass growth decreased, leaf senescence increased, and epiphytic algal cover was strongly reduced in acidified seawater. We also found that snail activity was negatively affected by acidic seawater. Our results suggest that continuing ocean acidification could be detrimental to the productivity and health of turtle grass meadows.