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Summary Report Constructed Oyster Reef Project In October 2013 an oyster reef was constructed in the Indian River approximately 40 ft.to 50 ft. east of the FDOT ditch (located along the northern boundary of the Spoonbill Marsh) discharge point to the Indian River. The footprint of the oyster reef measures approximately 75 ft. by 150 ft. with the long axis being oriented in a north -south direction or perpendicular to the direction of flow from the FDOT ditch. This oyster reef is a three dimensional structure constructed using concrete rubble that ranged in size from approximately 1.0 ft' to pieces approximately 13 ft' in size. A wire mesh foundation was used to minimize settling of the concrete rubble into the underlying sediments. The oyster reef generally extends up into the water column to a point approximately 0.5 ft. below the mean low tide elevation. The concrete rubble was hand stacked to maximize the volume of void space between the individual pieces of concrete. The resulting reef structure was distributed over an area of approximately 0.25 acres, while the estimated area of exposed concrete surface available for colonization by encrusting organisms was approximately 0.81 acres. The project objectives for constructing the oyster reef were defined as follows. 1. Create a three dimensional hard surface submerged structure in the Indian River with a relatively high surface area within a limited space that provides potential habitat for encrusting organisms such as oysters. Macro encrusting organisms (such as oysters, barnacles, and serpulid tubeworms) form the base of the food chain (for fish, crab, and shrimp species), and can provide micro refugia for certain larvae and juvenile fish species, and can provide significant additional surface area and micro -habitat for other attached organisms such as algae species that will modify water quality conditions within and around the reef. Oysters also can directly modify water quality conditions within and around the reef structure. 2. The concrete rubble was hand stacked to create void spaces throughout the reef structure of differing sizes, dimensions, and openings to the Indian River. These void spaces were intended to provide refugia for juvenile fish species and crustaceans (such as crab and shrimp species). The relative significance of the void space in the reef design was predicated on a working hypothesis that predicted the biomass of potential food items associated with the reef would be significantly greater (on a g/m2 basis) than any other area in the general vicinity of the reef, including the mangrove communities along the shoreline. A logical extension of the hypothesis then predicts the biomass of game fish including the reef in their home range, or that will be found over, within, or around the reef will be significantly greater than other nearby areas within the Indian River including nearby seagrass beds, if any. 3. Establish a relatively dense oyster population on the surface of the exposed concrete rubble. This oyster population will facilitate the removal of nitrogen from the water column flowing Page 1 of 4