Master’s Thesis Proposal Seminar

Abstract

Determining the physiological status of a subtropical seagrass, Thalassia testudinum, using pulse amplitude modulated (PAM) fluorometry

Dorothy Byron

As the Everglades ecosystem is restored to near its historic flow regime, water quality within Florida Bay will be affected. Currently conditions within Florida Bay vary between hypersaline and hyposaline, depending on location within the bay and time of year. In response to a change in Bay water quality, the benthic communities (i.e. the seagrass community) may shift from the Thalassia testudinum dominated ecosystem that currently exists. Physiological changes, such as amino acid concentration, chlorophyll a:b ratios, soluble carbohydrates and stable carbon isotope ratios occur much earlier then growth and morphological changes for seagrasses in response to stress. Short and long-term stress experiments to determine if T. testudinum can acclimate to dramatic changes in salinity may aid in predicting changes in species dominance.

This project investigates whether fluorescence data obtained with a pulse amplitude modulated (PAM) fluorometer may be used to assess the physiological status of seagrasses and thus be used as an early detection tool for predicting whether negative growth response may occur. This project also investigates the physiological state of T. testudinum within Florida Bay in response to salinity gradients as part of the Florida Coastal Everglades LTER project.