Meeting Abstract
Open ocean observations have shown that increasing levels of anthropogenically-derived atmospheric CO2 are causing acidification of the world’s oceans. Yet little is known about the carbonate chemistry of coastal areas where many ecologically and economically important organisms occur. We characterized the carbonate chemistry of seawater within an area dominated by seagrass beds (Eagle Harbor in Saint Joseph Bay, Florida), to determine the extent of variation in pH and pCO2 that local organisms are currently experiencing over monthly and daily timescales. Distinct diurnal fluctuations were observed at both timescales, indicating the influence of photosynthetic and respiratory processes on the local carbonate chemistry. Over the course of a year, values of pH ranged from 7.36 – 8.28 whereas when sampled on a daily basis over the course of a week, the range in pH was 7.70 – 8.06. Laboratory experiments exposing Lytechinus variegatus to different levels of CO2 indicate that delayed development and reduced somatic and reproductive production may already be occurring in individuals within the Harbor. The results of this study indicate that coastal species are experiencing far greater fluctuations in carbonate chemistry than previously thought. This has significant implications for the design of ocean acidification experiments in which nearshore species are utilized.
