Year of Publication

2014

Season of Publication

Fall

Paper Type

Master's Thesis

College

College of Arts and Sciences

Degree Name

Master of Science in Biology (MS)

Department

Biology

NACO controlled Corporate Body

University of North Florida. Department of Biology

First Advisor

Dr. Anthony M. Rossi

Second Advisor

Dr. Dale A. Casamatta

Third Advisor

Dr. Kelly J. Smith

Department Chair

Dr. Daniel C. Moon

College Dean

Dr. Barbara A. Hetrick

Abstract

Harmful algal blooms are exponential increases in autotrophic microorganisms that proliferate in such a way that the surrounding environment, the local economy and the health of regional populations are negatively affected. Among the causes of these blooms are anthropogenic inputs of excess nitrogen and phosphorus into the environment through overfertilization. Floating treatment wetlands (FTW) have emerged as a novel method of reducing the negative impacts of these nutrient inputs by using artificial rafts to float normally emergent wetland plants on the surface of water bodies to assimilate excess nutrients. Because their use is so new, only limited research has been performed on their effectiveness. This mesocosm-level study evaluated the performance of a FTW consisting of a community of yellow canna (Canna flaccida), blue flag iris (Iris hexagona) and bulltongue arrowhead (Saggittaria lancifolia) in simulated stormwater of varying nitrogen and phosphorus concentrations. The community of plants displayed nitrogen limitation, while the cyanobacteria-dominated algal community that developed displayed phosphorus limitation, leading to the conclusion that in order for this community of macrophytes to limit algal growth, nitrogen must be present to support their growth and concurrent assimilation of the algae-limiting nutrient phosphorus. Canna and iris were found to significantly outperform arrowhead in terms of biomass gains. The study also showed that the size of the plants may be of great importance in the ability of FTWs to limit algal development. Despite the fact that the community of plants in this study were unable to limit the development of algae, the use of FTWs remains promising and further research should be done to continue to enhance our understanding of their strengths and weaknesses.

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