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of fish as small as 2" anchovies against a rock background to as large as manatees and alligators . In the near- shore artificial reef systems to be studied , we also anticipate observing sea turtles that utilize the reef structures, and all turtle encounters will be documented and reported . The DIDSONTM will initially be used in concert with standard underwater video surveys to directly compare the utility of both methods . In addition to the new sonar-based and standard visual assessment techniques , direct fishery sampling procedures will also be employed to determine the species composition and relative abundance of fishes in the different habitats . Because each type of sampling technique has inherent limitations , a multi-faceted sampling program will be used . Sampling methods include beach seines, entanglement nets and traps . Seine nets are commonly-used tools for the quantitative assessment of fishes in many habitats . They are the primary sampling technique used by the FWCC 's Fisheries Independent Monitoring Program in the adjacent Indian River Lagoon and other estuaries throughout the state . However, current seine surveys of fishes in and near the surf zone are severely constrained by the difficulties in deploying and operating standard nets along the shore, especially when sharp drop-offs in the substrate , high surf, and strong along-shore currents prevent successful seining . Because of the difficulties in using standard seine survey techniques, the approach will be modified for use on the open coast. We will deploy large seine nets from a boat, using procedures similar to that employed by shore-based commercial seine net fishermen . The standard net will be a 300' long x 8 ' deep center bag seine made of 1 " mesh . To capture smaller juveniles that would pass through the 1 " mesh of the large net, a 50' long x 6 ' deep 1/4" mesh seine will be used when surf conditions permit . These nets will be used to sample surf-zone fishes in sandy areas adjacent to both natural and artificial reef structures . Although seines will provide a broad assessment of species within 100' of the shoreline , they will not be functional in deeper water, nor will they be efficient at capturing some of the species capable of avoiding the net during deployment. The grantee will seek regulatory permission from the FWCC Special Activities License Program for limited use of 100' x 6' multi-panel mesh gill nets to be deployed between moored buoys above reef structures in the targeted areas . The nets will be fished for no more than 30 minutes at a time , and will be constantly tended to ensure that sea turtles and large fishes are recovered and immediately released . To asses the abundance of fishes immediately within or adjacent to the reef structures , two types of weighted fish traps will be baited and deployed for 8- 12 hour periods from pre-set moorings on sandy habitats or immediately adjacent to reef habitats . Both of these traps are made of coated wire mesh , and are designed to capture small to medium sized demersal and bait fishes in saltwater environments (http ://www.catchnbait.com/pinfish-bait-fish- traps .htm ) . The small 11 " x 11 " x 22" trap is made with 0 . 5"" x 1 " mesh , and two 1 .5" wide funnel entrances . This low-profile trap should nestle easily within the contours of natural reef structures . The larger trap is 18" x 17" x 24" ( 1 " mesh ), with 2" funnel entrances . Both traps are equipped with "exit wall construction" to hinder fish escape . Full development of these sampling techniques will enable far more comprehensive analyses of the physical and community structure of east central Florida near-shore reefs than are presently possible . The techniques can then be used to improve our ability to determine impacts of beach nourishment on the protected coastal reef communities and to assess the function of different types of mitigation reef designs . Specific Research Objectives 1 ) Assessment of Benthic Habitat Structure . a) Gear testing and ground truth analysis : The RoxAnnTM sonar system will be used to assess the structure and composition of benthic habitats in the nearshore natural and artificial reef systems . The initial surveys will be conducted to "ground-truth" the RoxAnnTM to verify the signal characteristics of each type of bottom structure . These ground truth surveys will be conducted using sequential scanning of specific habitats using the RoxAnnTM followed by diver surveys using visual assessment, as well as video and still photography. b) Temporal and spatial assessment of benthic habitat structure : Following the initial development of RoxAnnTM sampling procedures, the grantee will establish a bi-monthly sampling program to evaluate the temporal and spatial changes in benthic habitat structure . This assessment Page 10 of 19