Florida Keys Coral Reef Monitoring Project
The Florida Keys National Marine Sanctuary and Protection Act (HR5909) designated over 2,800 square nautical miles of coastal waters as the Florida Keys National Marine Sanctuary. The Act requires the US Environmental Protection agency and the State of Florida to implement a Water Quality Protection Program in cooperation with NOAA. Programs in monitoring seagrass habitats, coral reefs and hardbottom communities, and water quality were instituted with the intent of integrating information with the central focus of water quality. The team of Phillip Dustan, University of Charleston, James Porter, University of Georgia, and Walter Jaap, Florida Marine Research Institute were asked to collaborate on the design and implementation of the coral reef/hard bottom community monitoring program.
The team, which brings a combined 60-plus years of field experience to the effort, considers this to be more than a simple monitoring project that will produce a general characterization of the Florida Keys Reefs. The question we have been asked to address (Are the reefs changing?), requires knowledge about the ecology of reef corals. It is a problem grounded in the theory of population biology.
The general objective of the coral reef / hardbottom monitoring program is to measure the status and trends of these communities to evaluate progress toward protecting and restoring the living marine resources of the Sanctuary. We are operating from a set of unproven but testable hypotheses. The null hypothesis (Ho) is that the coral communities are at dynamic equilibrium (no net change in percent cover or species richness over certain time scales). Alternative hypotheses (Ha) include: (1) overall reef decline in percent cover, species richness, and other measurable community parameters, (2) overall reef increase in measurable community parameters, (3) significant changes observed in individual reefs with no overall change on a landscape scale (decreases in one location balanced by increases elsewhere), or (4) changes are linked to specific regions of the landscape. The Coral Reef Monitoring Project provides the first real opportunity in the Florida Keys to address these questions at the spatial scales required to detect large-scale patterns and discriminate between these hypotheses. Furthermore, because the coral reef monitoring is integrated with the seagrass and water quality programs, the results can be used to focus research on determining causality, and can be used to inform and evaluate management decisions.
Station installation for the Florida Keys Coral Reef Monitoring Project required a year of field work. Our EMAP sampling protocol resulted in the selection of 9 hardbottom reefs, 10 patch reefs, and 23 offshore reefs distributed throughout the Upper, Middle, and Lower Florida Keys in a stratified random design. We will be sampling a total of 42 reefs, each with 4 video units, for a total of 168 video units providing a total coverage of 5,040 m2 in area recorded by video. Our protocol for video transect sampling, subject to minor modification following data analysis and final testing with respect to issues of sample sufficiency and object identification, is as follows. At each site there are four video units. A video unit consists of two marking stakes separated by approximately 22m distance. One is a starting point (anchor pin), the other is the finishing point (set pin) for a set of video transects. The center of a 2m crossbar is placed on each stake, and three floating polypropylene lines are stretched taut between the centers and ends of the crossbars. A lightweight brass chain is draped directly beneath each polypropylene line and the floating line is removed. Three passes will be made through each video station (down each side and down the center) with the video camera held vertically in the water column at a distance of approximately 50 cm from the reef surface.
Video transects are taken with a Hi8 camera; images are then framegrabbed from tape and written to CDs for data archiving and image analysis. We anticipate that we will write approximately 100 framegrabbed images per transect (a complete set of overlapping frames, see Figure 4) to write-once compact disk (CD); of these, a randomly selected non-overlapping set of approximately 40 to 80 framegrabbed images will be analyzed for percent cover of scleractinians and other organisms by a random dot overlay procedure. Taking the lower estimate of 40 images per transect (final decisions must await power analyses using real transect data from a selection of habitat types), we expect, then, at minimum, to write 50,400 framegrabbed images to CD medium; these will be read from CD-ROM drives by individual investigators and at least 20,160 framegrabbed images will be analyzed annually.
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