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of seasonal patterns in burial/emergence of benthic structures and changes in epibenthic biota will be conducted by repeated observations at sites marked by their GPS coordinates . 2) Evaluation of the DIDSONT" sonar for assessing fish abundance around benthic structures a) Initial equipment evaluation period : For initial evaluation of the DIDSONTM sonar, the grantee will arrange to lease the instrument for 2-3 weeks during the spring 2007 , and again in mid-late summer 2007 . Depending on the trial performances of the DIDSON the rental costs may be applied to eventual purchase of the unit which will remain the property of the Commission . b ) Evaluation methodology: A number of approaches will be used to test the sonar and to determine the optimal methods for use. One method will involve direct comparison between video and sonar observations . A single mounting frame will be constructed to hold both an underwater video camera and the DIDSONTM sonar transducer. The mounting frame and instrument array will be deployed in a variety of ways . When conditions permit, a diver will be able to swim along short transects , collecting simultaneous visual and sonar records of the objects in front of the array. At other times, both in calm conditions and when divers cannot operate safely, the instrument array will be attached to a weighted tripod . The tripod will then be lowered to the bottom and visual/sonar data on fish abundance and species composition will collected as fish (and perhaps sea turtles ) pass in front of the stationary observation platform . For both of these methods, we expect that the sonar will have a much greater observational range than the video system . However, as fish enter into the shorter range of the video and can be identified , we should be able to track and identify their sonar targets , developing the basis for sonar identification based on target shape and behavior. Additional deployment methods will be tested , including nighttime studies in selected locations using the sonar alone, and long-term (hours) evaluations that will help determine the temporal variability of fish abundance in specific habitats . c) Habitat assessment: The initial sensor methodology will be tested in the series of nearshore natural and artificial reef systems that will be characterized by the RoxAnnTM sonar. GPS locations of all video and sonar data will be used to characterize the fish fauna and substrate composition of each habitat type . 3) Direct Assessment of Fish Abundance and Species Composition . a) Assessment of fishes in near-shore sandy habitats adjacent to reef structures : Two types of seine nets will be employed to sample fishes in the surf zone near natural structures ; the existing artificial reef structures are too far offshore for inclusion in this portion of the study. Operations will require coordinated efforts of a boat crew and participants on shore. A 300' long x 8' deep center bag seine made of 1 " mesh will be used to capture the large and more mobile fishes that inhabit the near shore habitat . This net will be deployed from a boat as it moves outside the surf zone, stretching the net parallel to the shore . Lines attached to the ends of the net will be passed to the shore crew with a "pneumatic line thrower ' that is typically used to pass towing lines from tugs to other vessels , for mooring or rescue operations, and for military operations ( Restech Norway; www. restech . no). These line throwers can "shoot' a line over a distance of 70- 100 m . Once the lines are passed to shore, the crew will be able to draw the seine through the surf, thus capturing fish in the near shore region . A similar approach will use a 50 ' long x 6' deep ('/" mesh ) seine to capture juveniles that would pass through the mesh of the larger net. Once these techniques are developed , a bimonthly census of fishes will be conducted in the near-shore region that will involve at least 3-6 tows with each type of net in the vicinity of natural reef structures . Sites for these tows will be selected for their proximity to the sites surveyed by the RoxAnnT"' and DIDSONT instruments . If feasible, the DIDSONTM will be used to observe the deployment of the nets, and the behavioral responses of the fishes to the capture techniques . b) Assessment of fishes in and above reef structures : Two types of sampling gear will be used to directly sample the fish fauna immediately around natural and artificial reef structures . To capture the fishes moving above and around the reefs, 100' x 6' multi-panel mesh Page 11 of 19