Three Case Studies of Long-Term Changes in Phytoplankton Functional Diversity
Jay Pinckney, University of South Carolina
19 Oct 2012
Functional group diversity (FGD) provides a useful measure of ecosystem processes and changes in FGD over time may provide insights into the mechanisms responsible for regulating community structure and function. Furthermore, measures of phytoplankton FGD measures over time may be a useful metric for comparing the ecosystem states for different marine ecosystems. FGD indices were calculated using biomarker photopigment concentrations and ChemTax-derived phytoplankton group abundances for a variety of estuarine, coastal and ocean ecosystems to establish to establish numerical criteria for cross-system comparisons. Temporal changes in group diversity in the Neuse River Estuary (NC), Galveston Bay (TX), and the Cariaco Basin (Gulf of Mexico) were calculated to provide three case studies of systems undergoing long-term changes in community composition. The FGD approach offers a potentially useful tool for assessing both short- and long-term changes in phytoplankton biomass and community structure. Furthermore, this metric can be easily related to ecologically relevant properties such as food web structure, trophodynamics, and propensity for harmful algal blooms.