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- Parameter or Variable: BENTHIC SPECIES (REEF CREST) (measured); Units: Percent Cover; Observation Category: in situ; Sampling Instrument: photograph; Sampling and Analyzing Method: Bank crest repetitive photostations were selected within an area of dense high relief features harboring diverse benthic communities and marked by scuba divers using nails or eyebolts and numbered tags. Permanent mooring buoys 1, 2, and 3 were used for this study to enable easy access to the site by scuba divers. Repetitive photostations were installed on biologically interesting locations on high relief habitat, which included sites with scleractinian corals and sponges. In 1993, a total of 36 permanent photostations were installed. Over time several of these stations have been lost due to the dynamic environment at Stetson Bank (e.g., algal overgrowth, storm impacts, and fragile substrate). To maintain a sufficient number of repetitive photostation sites, new stations have been established, as needed, following the same selection criteria. Each station is located by scuba divers and photographed annually. Images were captured using a Sony A6500 digital camera in a Nauticam NA-A6500 housing with a Nikkor Nikonos 15 mm underwater lens mounted to a T-frame set at 1.75 m from the substrate, with two Inon® Z240 strobes set 1.2 m apart. A set of lasers were mounted to the pole of the T-frame, fixed at 30 cm, for spatial scale reference. To ensure repeatability of the area captured in each image, a compass and bubble level were mounted to the center of the T-frame to allow images to be taken in a vertical and northward orientation. Percent cover was calculated using CPCe® (Kohler & Gill 2006). Thirty points were randomly overlaid on each image and the benthos lying directly under each point was identified.; Data Quality Method: Data were reviewed by trained observers for quality and accuracy..
- Parameter or Variable: BENTHIC SPECIES (MESOPHOTIC) (measured); Units: Qualitative; Observation Category: in situ; Sampling Instrument: photograph; Sampling and Analyzing Method: Mesophotic permanent repetitive photostations were installed by ROV at biologically interesting sites ranging from 35.8 to 54.7 m depth. Locations were selected along hard bottom features in both coralline algae and deep reef habitat using historical ROV data. Photostations were physical marked with concrete block (25.4 cm x 25.4 cm x 15.2 cm) weighing 25 kg in air. The latitude and longitude of each site were recorded using the ROVs navigation system. Subsequently, the recorded latitude and longitude were used to locate each station. To create repeatable images annually, each station was assigned a heading from which the ROV oriented itself and collected high definition video imagery of the site, with the marker in view, and the original site images used for reference. From this video, still frames for each repetitive station were extracted. A downward facing photograph of each station was also captured, with the ROV positioned directly above the station marker, approximately 1 m above the bottom. The SubAtlantic Mohawk 18 ROV, owned by the National Marine Sanctuary Foundation (NMSF) and FGBNMS, and operated by University of North Carolina at Wilmington - Undersea Vehicle Program (UNCW-UVP), was used. The ROV was equipped with an Insite Pacific Mini Zeus II HD video camera with two Deep Sea Power & Light 3100 LED lights, a tool skid with an ECA Robotics five-function all-electric manipulator, and two parallel spot lasers set at 10cm in both the video and still camera frames for scale. Qualitative summaries of still frame image from the high definition video and downward facing still camera were conducted using ImageJ and Microsoft Excel. In 2015, key features were identified in each imaged and outlined using a color-coded key in Adobe Illustrator (e.g., scleractinian coral colonies). Key biological features were assigned a code using the first two letters of the genus and species name, along with a unique number for the image. (e.g., StIn_1 = Stephanocoenia intersepta colony 1). Measurements of key stony coral, octocoral, and black coral specimens were made using ImageJ and the reference scale lasers. Key features were compared between subsequent years, when possible. Comparisons document the loss, reduction, or expansion of key features and changes in general condition.; Data Quality Method: Data were reviewed by trained observers for quality and accuracy..
- Parameter or Variable: BENTHIC SPECIES (MESOPHOTIC) (measured); Units: Percent Cover; Observation Category: in situ; Sampling Instrument: photograph; Sampling and Analyzing Method: Transect sites were selected within potential hard bottom habitat to exclude soft bottom habitat. Habitat was defined using 2 m resolution bathymetry raster with focal statistics calculated for range (minimum to maximum depth) within a 5 m x 5 m rectangle. Cells with a depth range >1 m were identified as potential habitat. A 33.5 m contour was used to restrict the extent of the layer, limiting surveys to depths greater than those conducted by scuba divers on the bank crest. Annually, 30 survey sites were randomly generated within mesophotic habitat, distributed proportionality by area between habitats: 15 in coralline algae reef and 15 in deep reef. The same SubAtlantic Mohawk 18 ROV described in Field Methods for repetitive photostations was used. Images were collected with the ROV still camera facing downward, perpendicular to the substrate. Transects started at each of the random drop sites and continued for 10-minutes along hard bottom habitat while the ROV traveled at one meter above the bottom, at a speed of approximately 1 knot per hour, taking downward facing images every 30 seconds. Mesophotic transects images were processed to remove silted, shadowed, out of focus, or soft bottom images (images with <50% hard bottom). If a transect did not have at least nine useable images, it was removed from the analysis. Percent cover was calculated using CPCe® (Kohler & Gill 2006). Five hundred points per transect were distributed evenly amongst images and then randomly overlaid on each image. The benthos lying directly under each point was identified. Habitats are based on definitions in Schmahl G.P., Hickerson E.L., Precht W.F. (2008) Biology and Ecology of Coral Reefs and Coral Communities in the Flower Garden Banks Region, Northwestern Gulf of Mexico. In: Riegl B.M., Dodge R.E. (eds) Coral Reefs of the USA. Coral Reefs of the World, vol 1. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-6847-8_6; Data Quality Method: Data were reviewed by trained observers for quality and accuracy..
- Parameter or Variable: BENTHIC SPECIES (REEF CREST) (measured); Units: Percent cover; Observation Category: in situ; Sampling Instrument: photograph; Sampling and Analyzing Method: Transect sites were selected within high and low relief habitat, defined using 1 m^2 resolution bathymetric data. Depth range was calculated with a 5 m x 5 m rectangular window, and reclassified to define low relief habitat (<1 m range) and high relief habitat (>1.1 m range). A 33.5 m contour was used to restrict the extent of the layer, limiting surveys to within depths that would allow scuba divers sufficient time to conduct surveys and avoid decompression. Sites were distributed proportionally by area between habitats: 20 low relief sites and 10 high relief sites. A still camera, mounted on a 0.65 m T-frame with a bubble level and strobes, was used to capture non-overlapping images of the reef, where each image captured approximately 0.8 x 0.6 m (0.48 m^2). Each transect was designed to capture 8.16 m^2 of benthic habitat, therefore requiring 17 images. Spooled fiberglass 15 m measuring tapes with 17 pre-marked intervals (every 0.8 m) were used as guides, providing a 0.2 m buffer between each image to prevent overlap. A Canon Power Shot® G11 digital camera in an Ikelite® housing with a 28 mm equivalent wet mount lens adaptor, with two Inon® Z240 strobes set 1 m apart on the T-frame, was used. Percent cover was calculated using CPCe® (Kohler & Gill 2006). Five hundred points per transect were distributed evenly amongst images and then randomly overlaid on each image. The benthos lying directly under each point was identified.; Data Quality Method: Data were reviewed by trained observers for quality and accuracy..
- Parameter or Variable: FISH CENSUS (REEF CREST) (measured); Units: Density (#/100 m^2); Observation Category: in situ; Sampling Instrument: swimmer/diver; Sampling and Analyzing Method: Scuba divers, using the modified Bohnsack and Bannerot (1986) stationary visual fish census technique, restricted observations to an imaginary cylinder with a radius of 7.5 m, extending from the benthos to the surface. All fish species observed within the first five minutes of the survey were recorded as the diver slowly rotated in place above the bottom. Immediately following this five-minute observation period, one rotation was conducted for each species noted in the original five-minute period to record abundance (number of individuals per species) and fork length (within size bins). Size was binned into eight groups; <5 cm, ≥5 to <10 cm, ≥10 to <15 cm, ≥15 to <20 cm, ≥20 to <25 cm, ≥25 to <30 cm, ≥30 to <35 cm. If fish were >35 cm, each individual size was recorded based on visual estimation by divers. Divers carried a 1 m PVC pole marked in 10 cm increments to provide a reference for size estimation. Each survey required, at minimum, 15 minutes to complete. Transitory or schooling species were counted and measured at the time they moved through the cylinder during the initial five-minute period. Notes on the habitat within each survey area were obtained, including information on benthic relief Surveys began after sunrise and were repeated throughout the day until dusk. There were two survey types: Random and Repetitive. Random survey start location were selected in conjuction with random transects. Survey sites were selected within high and low relief habitat, defined using 1 m^2 resolution bathymetric data. Depth range was calculated with a 5 m x 5 m rectangular window, and reclassified to define low relief habitat (<1 m range) and high relief habitat (>1.1 m range). A 33.5 m contour was used to restrict the extent of the layer, limiting surveys to within depths that would allow scuba divers sufficient time to conduct surveys and avoid decompression. Sites were distributed proportionally by area between habitats: 20 low relief sites and 10 high relief sites. Repetitive survey sites were co-located with select benthic repetitive photostations where the station marker was the center of the fish survey cylinder. Counts were converted to density per 100m^2; Data Quality Method: Data were reviewed by trained observers for quality and accuracy..
- Parameter or Variable: FISH CENSUS (MESOPHOTIC) (measured); Units: Density (#/100 m^2); Observation Category: in situ; Sampling Instrument: video camera; Sampling and Analyzing Method: Fish were visually assessed by ROV using forward facing video footage obtained from mesophotic random transects. Observations of fish were restricted to the field of view of the ROV’s forward facing high definition video camera. Transect sites were selected within potential hard bottom habitat to exclude soft bottom habitat. Habitat was defined using 2 m resolution bathymetry raster with focal statistics calculated for range (minimum to maximum depth) within a 5 m x 5 m rectangle. Cells with a depth range >1 m were identified as potential habitat. A 33.5 m contour was used to restrict the extent of the layer, limiting surveys to depths greater than those conducted by scuba divers on the bank crest. Sites were randomly generated within mesophotic habitat, distributed proportionality by area between habitats: 15 in coralline algae reef and 15 in deep reef. The SubAtlantic Mohawk 18 ROV was used. Transects started at each of the random drop sites and continued for 10-minutes along hard bottom habitat while the ROV traveled at one meter above the bottom, at a speed of approximately 1 knot per hour. Counts were converted to density per 100m^2. Habitats are based on definitions in Schmahl G.P., Hickerson E.L., Precht W.F. (2008) Biology and Ecology of Coral Reefs and Coral Communities in the Flower Garden Banks Region, Northwestern Gulf of Mexico. In: Riegl B.M., Dodge R.E. (eds) Coral Reefs of the USA. Coral Reefs of the World, vol 1. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-6847-8_6.; Data Quality Method: Data were reviewed by trained observers for quality and accuracy..
- Parameter or Variable: VIDEO TRANSECT (measured); Units: N/A; Observation Category: in situ; Sampling Instrument: video camera; Sampling and Analyzing Method: Video transects were conducted along three permanent 100 m transects. Each transect was marked using eyebolts every 25 m. Bolts were marked with the transect number and the eyebolt position along the transect. Transect start locations are available on the site maps. Before recording on video, a line was laid between the eyebolts to mark the transect. Video was recorded using a Sony® Handycam® HDR-CX350 HD video camera in a Light and Motion® Stingray G2® housing. A two-meter-long plumb bob was secured to the front of the camera housing to maintain distance above the bottom. The diver swam along the transect line, following the line with the plumb bob, maintaining the camera at a 45o angle to the seafloor.; Data Quality Method: N/A.
- Parameter or Variable: WATER QUALITY (MOORED) (measured); Units: degrees C; psu; Observation Category: in situ; Sampling Instrument: CTD - moored CTD; Sampling and Analyzing Method: Water temperature and salinity on the crest of Stetson Bank (24 m), was collected continuously using a Sea-Bird® Electronics Inc. 16plus V2 CTD, equipped with a WET Labs ECO NTUS turbidity meter. The loggers were installed on a large railroad wheel in the midsection of the bank crest. The instrument was downloaded quarterly and factory service of the instrument was performed annually. Onset® Computer Corporation HOBO® Pro v2 U22-001 thermographs were used as a backup to the Sea-Bird instrument and recorded temperature on an hourly basis. A HOBO® thermograph deployed at the 30 m station, located on the northerly edge of the bank crest, recorded temperature hourly. Another HOBO® thermograph was installed at 40 m, also along the northern edge of the bank crest, to record temperature hourly. The loggers were downloaded and maintained on a quarterly basis. The HOBO® thermistors were attached to eyebolts embedded in the substrate. Due to instrument download schedule, some data from the previous and subsequent year are included in this data package. All measurements were later processed to daily averages.; Data Quality Method: Data were reviewed by trained observers for quality and accuracy..
- Parameter or Variable: WATER QUALITY (PROFILES) (measured); Units: degrees C; psu; pH; DO; turbidity; fluorescence; Observation Category: in situ; Sampling Instrument: CTD; Sampling and Analyzing Method: Water column profiles were collected using a Sea-Bird Electronics 19plus V2 to record temperature, salinity, pH (on NBS scale), turbidity, fluorescence, and dissolved oxygen (DO) every ¼ second during the column profiles. Data were recorded following an initial soaking period, on the down cast phase of each deployment, while the CTD was brought to the surface at a rate <1 m/sec.; Data Quality Method: Data were reviewed by trained observers for quality and accuracy..
- Parameter or Variable: WATER QUALITY (SAMPLES) (measured); Units: variety; Observation Category: in situ; Sampling Instrument: CTD; Sampling and Analyzing Method: Water samples for nutrient and seawater carbonate chemistry parameters were collected quarterly. Samples were collected using a sampling carousel equipped with a Sea-Bird® Electronics 19plus V2 CTD and six OceanTest® Corporation 2.5 liter Niskin bottles, with bottles activated at specific depths. When this instrument was not available due to maintenance or operational issues, samples were collected using a manually triggered handheld Niskin bottle, lowered on a measured line. Each quarter, three nutrient samples, with one replicate for each depth, were collected near the seafloor (approximately 20 m depth), mid-water (10 m depth) and near the surface (1 m depth). Ocean carbonate samples were collected at identical depth intervals, with one replicate collected with the surface (1 m) sample. Once samples were collected, subsamples were transferred as follows: chlorophyll-a subsamples were transferred to 1000 ml brown glass containers with no preservatives; reactive soluble phosphorous subsamples were placed in 250 ml white plastic bottles with no preservatives; and ammonia, nitrate, nitrite, and total nitrogen subsamples were transferred to 1000 ml white plastic bottles and preserved with sulfuric acid. Within minutes of sampling, labeled sample containers were stored on ice at 4 °C and a chain of custody was initiated for processing at an EPA certified laboratory. The samples were transported and delivered to A&B Laboratories in Houston, TX within twenty-four hours of collection. Water samples for seawater carbonate chemistry measurements were collected following methods requested by the Carbon Cycle Laboratory (CCL) at Texas A&M University – Corpus Christi (TAMU-CC). Samples were collected in ground neck borsilicate glass bottles. Bottles were filled using a 30 cm plastic tube connected to the filler valve of the Niskin bottle. Bottles were rinsed three times using the sample water, filled carefully to reduce bubble formation, and overflowed by at least 200 ml. A total of100 μl of saturated HgCl2was added to each bottle, which was then capped and the stopped was sealed with Apiezon® grease and secured with a rubber band. The bottles were then inverted vigorously to ensure homogeneous distribution of HgCl2. Samples were then stored at 4 °C and sent to CCL at TAMU-CC, in Corpus Christi, TX. Each sample was analyzed for pH, alkalinity, dissolved inorganic carbon (DIC), saturation state with respect to aragonite (Ωaragonite).; Data Quality Method: Data were reviewed by trained observers for quality and accuracy..
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