Document Type

Internship Report

Publication Date

Fall 2013


This study was created to collect and analyze data on the condition of mangroves, seagrass beds and coral reefs surrounding Key Biscayne, and to develop a means of disseminating this information to residents. It comprises the following components: 1) the design of a robust sampling protocol for the ecological assessment of mangrove, seagrass, and coral reef habitats, and 2) the implementation of field surveys to assess the status of these habitats at select sites around Key Biscayne. Key findings include: Mangroves: basin mangroves at Crandon Park exhibited average basal area when compared with other mangroves in the region. High densities of R. mangle were the primary contributor to basal area, suggesting these mangroves are adversely affected by storm activity or high winds. Increased freshwater input is likely lowering soil salinity and preventing these mangroves from becoming hypersaline. Seagrass beds: Seagrass cover at study sites around Key Biscayne was low compared to recent studies of central Biscayne Bay. Maximum macroalgal cover for Key Biscayne occurred at its beaches. Epiphytes were widespread and in medium to high densities across the majority of study sites, indicating increased nutlient input in these areas. Coral reefs: Biscayne reefs were not currently undergoing significant tissue loss due to environmental stressors such as disease or coral bleaching, and exhibited increased surface area of scleractinian corals compared to earlier surveys of the same reefs. A small change in relative species compositions, from sediment-intolerant species to sediment-tolerant species, suggests that sedimentation might be affecting Biscayne reefs. Biscayne reefs were also dominated by dense turf macroalgae, which served as indication that both nutlient levels and herbivory are low in this area. All the data collected in this survey were incorporated into Key Biscayne’s Citizen Scientist web portal (, providing Key Biscayne residents ready access to ecological information about their coastal resources.


Department: MBF

MPS Track: TME

Location: Key Biscayne Community Foundation

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