Project Title: 2017 NOAA Ship Nancy Foster expedition to West Florida Slope and Oculina Banks
Project Summary

NF-1708: August 13-31, 2017  Chief Scientist: Peter Etnoyer (Leg 1: August 13-24) and Daniel Wagner (Leg 2: August 27-31)

1. conduct benthic surveys using a deep-water remotely operated vehicle (ROV) in areas that have been proposed for the establishment of new habitat areas of particular concern (HAPC) on the West Florida slope;

2. collect biological specimens of deep-sea corals, sponges and their associated taxa using the manipulator arm of the ROV;

3. collect multibeam bathymetry and backscatter data in areas that have not yet been mapped at a high resolution, focusing on areas of the West Florida slope and peripheries of existing coral HAPCs in the South Atlantic Bight;

4. collect water samples and CTD data to support ongoing studies on seawater carbonate chemistry;

5. opportunistically collect water column acoustic data to characterize the relative abundance of pelagic fishes of the region.

Anticipated Management Application(s)

The objectives of the expedition were to survey, sample, and map deep-sea coral ecosystems in the eastern Gulf of Mexico and South Atlantic Bight between ~200-1000 m depths, focusing on priority areas identified by the Gulf of Mexico Fishery Management Council (GMFMC) and the South Atlantic Fishery Management Council (SAFMC).

Location(s):
  • Oculina Banks
  • West Florida Slope
Point of Contact: Office of the Point of Contact:
  • NOS NCCOS
Project Title: 2017 NOAA Ship Nancy Foster expedition to West Florida Slope and Oculina Banks
Methods/Approach

ROV seafloor surveys Seafloor surveys were conducted on leg 1 of the expedition using the ROV Odysseus operated by Pelagic Research Services. During each seafloor survey, the ROV descended to the seafloor and transited at an altitude of 1-3 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 camera (SubC 1Cam Alpha MK5 HD) that collected continuous video and photographs approximately every 5 seconds while the seafloor was in view, (2) parallel lasers projected 10 cm apart that were used to scale images collected by the camera, (3) a SBE 19plus SeaCat CTD profiler that collected conductivity, temperature, depth, salinity and dissolved oxygen every 0.25 seconds, and (4) a Trackpoint ultra-short baseline (USBL) sonar navigation system calculated the ROV’s position in real time. The ROV-mounted CTD was only operational during some of the dives (1-4, 8, 12-14). Similarly, the USBL navigation system was only operational during the first four ROV dives of the expedition. For all other dives of the expedition (dives 5-14), ROV position was approximated using the ship position and heading, ROV tether length, ROV depth, as well as noteworthy features (e.g., ridges, mounds) seen during the dive that were cross-referenced with contours in existing multibeam data of the area.

On the first two ROV dives of the expedition, short transects, 5-15 minutes in duration and corresponding to a survey distance of ~100-300 m, were conducted at the beginning, middle, and end phases of each dive. During transects, the ROV was intended to transit at a constant altitude (~1 m), speed (~0.5 knots) and heading, with the camera maintaining a wide and fixed frame. However, strong currents hindered transiting at a constant height and speed over ground. As a result, the transect methodology was abandoned after the second dive of the expedition. Instead, scientists focused on taking photos approximately every 5 seconds while the ROV was moving consistently along the seafloor, and noting the predominant substrates encountered throughout each dive.

Specimen collections A limited number of specimens were collected during seafloor surveys using the manipulator arm of the ROV Odysseus. For each collected specimen, the date, time (both in UTC), depth, latitude, and longitude (both from the ship position) were recorded at the time of collection. Once specimens were brought 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 and processed separately. Once photographed and labeled, specimens were preserved in non-denatured, 95% ethanol. Small clippings of most specimens were also preserved separately in 5% formalin, dry, liquid nitrogen, RNAlater® and Whatman Flinders Technology Associates (FTA®) cards.

Multibeam mapping surveys Mapping operations consisted of collecting multibeam bathymetry and backscatter data with the ship’s Kongsberg EM710 echosounder. During leg 1, mapping surveys were mostly conducted during nighttime or whenever the ROV was not in the water, and focused on areas in the 200-300 m depth range in the vicinity of proposed HAPCs on the West Florida slope. On leg 2, mapping surveys were conducted during both day and night, and focused on areas close to existing coral HAPCs off the south and east side of Florida at depths between 70-750 m. Additionally, leg 2 prioritized mapping shallow-water (<150 m) areas, as NOAA Ship Nancy Foster is one of the few ships in the NOAA fleet with mapping systems that can target these depths.

CTD casts and water sample collections CTD casts were performed on both legs of the expedition in order to collect sound velocity profiles needed to calibrate the ship’s multibeam echosounders, as well as to collect water column environmental data and seawater samples for carbon chemistry studies. CTD casts were conducted using the ship’s SBE-32 Niskin bottle carousel with the attached SeaBird SBE 19 sensors. During each cast, continuous water column data on depth, fluorescence, salinity, and dissolved oxygen were collected. Additionally, during some CTD casts, 500 mL water samples were collected at predetermined depths between 20-1000 m, and preserved using 100 μL of saturated mercuric chloride for studies on seawater carbonate chemistry. These water samples were all sent to the U.S. Geological Survey Carbonate Analytical Laboratory in St. Petersburg after the expedition for measures on total alkalinity and total inorganic carbon. In addition to using the SBE-32 Niskin bottle carousel, during the second leg of the expedition some CTD casts were also performed using the underway CTD system of the ship. This system was not available during the first leg of the expedition, due to the space limitations on the deck caused by the large footprint of the ROV.

Water column acoustics surveys The first leg of the expedition included the collection of water column acoustic data using the ship’s Simrad EK60 fisheries acoustics suite. In general, water column acoustic data were collected at the same time as seafloor mapping surveys, and typically occurred at depths ranging between 200-300 m. Additionally, several targeted linear transects were conducted in each proposed HAPC. These ran from east to west, perpendicular to a deep ridge feature running from north to south near ~400-500 m depths, and over presumed Lophelia pertusa mound features.

Project Results and Management Outcomes  None Defined
Project Title: 2017 NOAA Ship Nancy Foster expedition to West Florida Slope and Oculina Banks
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