Mangroves provide many ecosystem services in coastal environments around the world. These include water quality improvement, creating habitats for terrestrial and aquatic species, and stabilizing shorelines. In central Florida, the red mangrove Rhizophora mangle is a common species in coastal wetlands, and recently the number of individuals successfully recruiting to intertidal oyster reefs has greatly increased, possibly because biogeochemical hot spots are present on oyster reefs due to nutrient-rich biodeposits from the live oysters. To understand how well R. mangle responds in terms of survival and growth to the suite of variables associated within these two unique habitats, I tracked 300 seedlings (n = 30 per site on 5 oyster reefs and 5 shoreline sites) that were approximately 1-year old at the start of my project. Monitoring occurred over 12 months (start: August 2022). Monthly data collection included above-ground measurements for each mangrove (survival, height, stem circumference, light availability, leaf count, herbivory, leaf area, and chlorophyll levels) of the seedlings, while below-ground measurements quantified biogeochemical properties of the soil adjacent to mangroves at each site. Survivorship declined over time for both habitats, but survivorship was greater on oyster reefs (cox regression model, p= 0.002). Results suggest greater stem circumference and ammonium concentrations at oyster reef sites. With the data gathered from this study, I determined that oyster reefs have conditions that provide better chances for long-term survival and growth for R. mangle in Mosquito Lagoon. This possibility should be considered on all estuarine systems where mangroves and oyster reefs intersect.
Mekail Negash
Dr. Linda Walters, Advisor
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