Abstract
The fecal indicator bacteria (FIB), enterococci, is used to issue marine beach advisories. Measurements of this group of bacteria have been increasing in recent years leading to an increase in the number of beach advisories. Identifying the sources of enterococci are imperative to keeping beaches open. Extensive research has been conducted to evaluate bulk water and sediment matrices as potential sources, but much less research has evaluated the water from the sea surface microlayer (SML) and macroalgae (specifically Sargassum spp.). The objective of this dissertation is to fill the information gap by evaluating the exchange of microbes within the various beach matrices that include SML, bulk water, sediment, air, and Sargassum spp. plus the human and animal reservoirs that harbor this bacterium. Given that this study found that Sargassum spp. was found to represent a significant source, composting this resource was evaluated as a potential management solution for times when beach water is degraded due to excessive influxes of this macroalgae. To evaluate these objectives four studies were conducted. These included 1) a study on the microbial communities in the SML and the potential association with microbes in other matrices, 2) a study specifically examining sediment, decomposing seaweed, human, and other animals as sources of enterococci and their contributions to bacterial exceedances, 3) a study of composting Sargassum spp. and the quality of compost that is created as compared to various guidelines, and 4) a study evaluating the economics of Sargassum spp. composting from the perspective of a municipality. Two of the four studies assessed the potential sources of bacteria levels at the beach, while the other two focused specifically on the management solution of the one main source identified (Sargassum spp.).