FINAL REPORT- SURVEY OF FISH ASSEMBLAGES AND BENTHIC HABITAT AT PULLEY RIDGE, S.W. FLORIDA SHELF; PART 1- CHARACTERIZATION OF BENTHIC HABITAT AND BIOTA WITH DOCUMENTATION OF HARD/LIVE BOTTOM. REPORT TO NOAA FISHERIES.

Abstract

Seven sites were surveyed with the NOAA Superphantom II ROV on Pulley Ridge. A single ROV dive (~1 hr) was completed at each of the seven sites. Video/photographic transects were used to document and characterize the benthic habitat and biota and allowed for quantitative estimates of densities and sizes of biota. The primary protocol was to document the presence or absence of hard-bottom habitat. Qualitative estimates of size of habitat features and size of benthic invertebrates were made from videotapes and digital images using the cameras’ parallel 10 cm lasers. During the transects the ROV was kept close to the bottom (\u3c 0.5 m) whenever possible. The video and digital still cameras were ~0.5 m off the bottom and angled down ~45o during the transects. Periodically (~1/ minute) the ROV was stopped and the digital still camera was turned down 90o for quantitative photos. Depending on the cameras’ degree of zoom, the field of view ranged from 25 cm to ~2 m but can be determined by the lasers in the image. The observer’s field of view which was limited by visibility of the water column and available light from the ROV was approximately 30-40 ft. Throughout each dive the Investigator (JR) made verbal notes on the videotapes and detailed written notes describing all aspects of the habitat and benthic biota. The log form included time, depth, photo number and description of each photograph, habitat description (substrate, shape and height of feature), and description of density and size of benthic invertebrates