Methods/Approach
Seafloor surveys were conducted using the ROV Mohawk operated by the Undersea Research Program at the University of North Carolina at Wilmington. During each seafloor survey, the ROV transited at an altitude of approximately <1 m off the bottom and a speed over ground of <0.50 knots. The ROV was equipped with the following equipment that collected continuous data throughout each dive: (1) a high-definition, forward-looking video camera, used to record each dive once on bottom until leaving for the surface (2) a high-definition, forward-looking still camera to collect images of interesting biology and photograph transect paths (3) parallel lasers projected 10 cm apart, which were used to scale images collected by the video and still cameras, (4) an Imaginex 881 sonar system linked to a Trimble SP461 GPS/heading receiver, which provided position information at <0.5 m accuracy every two seconds, and (5) a tool skid mounted on the bottom of the ROV which includes an ECA Robotics five-function manipulator arm, retractable bio box with three dividers, four rotatable collection buckets, and reversible/variable speed pump for suction hose usable by way of the manipulator to collect items into the buckets
Five minute transects were conducted over the varying habitat types encountered during each ROV dive. Transects were conducted at approximately 1 m altitude off the bottom traveling at 0.5 knots. Photographs were collected using the still-image camera each time the reference lasers passed over benthic colonies or every 20 seconds, depending on biological density at each given site. A voice recording was maintained in the HD video recording to note the start and end of each transect via microphone connected to the recording system. This information will be used in the post-processing of transect data. Typically, two transects were conducted during each dive.
A total of 54 biological specimens and two sediment samples were collected during seafloor surveys using the manipulator arm of the ROV. For each collected specimen, the date, time, latitude, longitude, and depth, was recorded at the time of collection. Once specimens were brought back onto the deck of the ship, they were examined for commensal organisms, labeled, photographed and inventoried into a database containing all relevant metadata. Any commensal organisms found on the specimens were separated from the sample and processed separately. Once photographed and labeled, specimens were preserved in an appropriate medium.
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Project Results and Management Outcomes
None Defined
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