Carbon Isotope biogeochemistry of Crystal Lake

Abstract

<p>The element carbon has two stable isotopes in nature, 12C and Be. Because of mass differences of isotopes, the physicochemical properties of isotopes of an element are not identical and cause isotope fractionation in nature. Photosynthesis is one such process where the lighter 12C02 is preferentially assimilated into the plant tissue. Photosynthetic pathways are the primary factors that fractionate carbon isotopes. The environmental conditions, such as temperature and pH, nutrient availability, the concentration of DIC (dissolved inorganic carbon) also influence the extent of carbon isotope fractionation during photosynthesis. In aqueous environments, the carbon isotope composition of DIC reflects the nutrient availability in water as more nutrient would enhance more preferential uptake of 12C02 during photosynthesis. The preferential uptake of the light carbon isotope during photosynthesis would enrich the heavier carbon isotope in the residual Ole. However, even with the same environmental conditions and nutrient availability, each phytoplankton group may fractionate carbon isotope differently. To quantify the relationship between nutrient availability and carbon isotope composition of DIC of the residual water, one needs to know the carbon isotope fractionation factors of the various members of the algal community predominate at different parts of the year. The objectives of this project are to study seasonal variation of carbon isotopes in DIC, its relationship to nutrient concentration, water chemistry, and the seasonal succession of algal community. The main lake of Crystal Lakes will be the study site it is located in Medway, Clark County, Ohio. The surface area of this region is about 0.044 Km2 and the maximum depth about 11.9 m. The sampling is done throughout the year starting April until December. The samples collected will be used for major water chemistry, for carbon isotope analysis and for identifying the algal communities.</p><p>This presentation occurred at the Wright State University Campus-Wide Celebration of Research, Scholarship and Creative Activities on April 16, 2010</p>