Dr. Jane M Caffrey

Seagrasses are essential in coastal ecosystems by providing important ecological benefits, including improved water quality, support for complex food webs, and stabilization of sediments which can reduce shoreline erosion. Increased nutrient concentrations can cause seagrass decline through light reduction caused by the overgrowth of epiphytes, macroalgae, or phytoplankton. Previous research has shown significant epiphyte biomass, nitrogen fixation and diazotroph abundances associated with seagrasses. Phytoplankton contain unique combinations of chlorophyll compounds. Chlorophyll analysis can provide biomass and be used to estimate general phyla information based on presence and abundance of certain chlorophyll compounds. This study will examine biomass, abundance and community composition of epiphytes associated with two species of seagrasses, Thalassia testudinum and Halodule wrightii.

Seagrass beds are an essential part of estuaries and shallow coastal waters that provide many services and support to the ecosystem. They serve as nurseries for marine life, decrease shoreline erosion and increase sediment stabilization.
Disturbances to seagrass beds can be natural such as stingray pits, or they can be anthropogenic such as propeller scars.
Stingray pits are a result of bioturbation from the stingray feeding on benthic organisms which causes a deep depression in the seagrass beds, but also can release trapped nutrients from the sediment.
Natural disturbances are expected to be more abundant, and to occur more frequently in seagrass beds.

The Gamma primer showed nonspecific primer annealing, the literature information will be checked in order to find out if the correct sequence was used to predict optimal parameters. With the correct parameters for the CYB primer, this one will proceed to be used with the samples of Thalassia testudinum and Halodule wrightii from Santa Rosa Sound to continue the study on nitrogen fixation by epiphytes. The next steps are to finish DNA extraction of epiphytes from the seagrass blades collected and use these primers to identify the presence of the nifH genes.