Okeanos Explorer (EX1711): Gulf of Mexico (ROV and Mapping)

Vessel: NOAA Ship Okeanos Explorer; Expedition Dates: November 29 - December 21, 2017

Project Principals: Brian Kennedy, NOAA/OAR/OER (Expedition Coordinator); Michael White, NOAA/OAR/OER (Mapping Lead)

Operations will include the use of the ship's deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, Knudsen 3260 chirp sub-bottom profiler sonar, and Teledyne Acoustic Doppler Current Profiler), XBT and CTD casts in support of multibeam sonar mapping operations, OER's two-body ROV Deep Discoverer and Seirios, and the ship's high-bandwidth satellite connection for continuous real-time ship-to-shore communications.

South Reed

Area

South Reed; Gulf of Mexico

Overview

Purpose

The dive targeted an area proposed by the Gulf of Mexico Fishery Management Council as a new Habitat Area of Particular Concern (HAPC). The area showed high habitat suitability for deep-sea corals in models. Therefore, the primary objective of this dive was to acquire baseline information on the distribution and abundance of benthic fauna, in particular corals and sponges. By climbing two escarpments and crossing a terrace, the dive encountered a variety of benthic habitats and communities. This dive generated information on the distribution, diversity, and habitat use of these communities.

Escarpment Canyon

Area

Escarpment Canyon; Gulf of Mexico

Overview

Purpose

The Florida Escarpment southwest of Pulley Ridge has a complex canyon and promontory system with relief exceeding 1000 m. These extraordinary "spur and groove" or "saw-tooth" structures have steep cliffs and canyon features with extensive hard substrate walls that are ideal for the establishment of deep-water sessile communities, as well as soft-sediment habitats. This dive site, given the canyon location, allowed us to encounter and characterize a variety of benthic habitats and associated communities, including the distribution and abundance of corals and sponges. This generated information on the distribution, diversity, biogeography, and connectivity of these communities.

Okeanos Ridge

Area

Okeanos Ridge; Gulf of Mexico

Overview

Purpose

The dive targeted an area proposed by the Gulf of Mexico Fishery Management Council as a new Habitat Area of Particular Concern (HAPC). The area showed high habitat suitability for deep-sea corals in models. Therefore, the primary objective of this dive was to acquire baseline information on the distribution and abundance of benthic fauna, in particular corals and sponges. By climbing two areas of the escarpment and crossing the exposed top edge between, the dive encountered a variety of benthic habitats. This dive generated information on the distribution, diversity, and habitat use of these communities, which has management implications.

Long Mounds

Area

Long Mounds; Gulf of Mexico

Overview

Purpose

The dive targeted an area proposed by the Gulf of Mexico Fishery Management Council as a new Habitat Area of Particular Concern (HAPC). The area showed high habitat suitability for deep-sea corals in models. Therefore, the primary objective of this dive was to acquire baseline information on the distribution and abundance of benthic fauna, in particular corals and sponges. By beginning in a valley, climbing an escarpment and then crossing the exposed top edge, the dive encountered a variety of benthic habitats. This dive generated information on the distribution, diversity, and habitat use of these communities, which have management implications.

Incised Escarpment Ridge

Area

Incised Escarpment Ridge; Gulf of Mexico

Overview

Purpose

The dive was one of a comparative pair exploring the geology and associated communities at 1800-2300 m on the northern end of the West Florida Escarpment. This first dive explored the southern section, where the escarpment is marked by promontories. The second dive will survey the northern section of the escarpment, where the promontories are reduced, resulting in steep cliffs. ROV exploration of these features aided our understanding of the geological structure and origin of this area of the Florida Escarpment. Additionally, these pronounced features hosted many deep-water sessile communities, for which we collected baseline data on the distribution, abundance, diversity, biogeography and connectivity. A midwater survey also took place during this dive.

Smooth Escarpment Ridge

Area

Smooth Escarpment Ridge; Gulf of Mexico

Overview

Purpose

The dive was one of an exploratory pair that compared the geology and associated communities in 1800-2300 m at the northern end of the West Florida Escarpment. This second dive explored where the escarpment is very steep as a result of reduced promontories. ROV exploration of these features aided our understanding of the geological structure and origin of this area. Additionally, these exposed areas of hard substrate hosted deepwater sessile communities, for which we collected baseline data on their distribution, abundance, diversity, biogeography and connectivity.

Wreck 15377

Area

Wreck 15377; Gulf of Mexico

Overview

Purpose

To explore and characterize wreck 15377.

AT 251

Area

AT 251; Gulf of Mexico

Overview

Purpose

The dive was located on a BOEM seismic anomaly located in a geologically active area. The dive explored this feature, which included two possible locations of methane bubble plumes (confirmed during multibeam surveys by the NOAA Ship Okeanos Explorer). ROV exploration of this feature aided our understanding of the geological composition and origin of this area. Additionally, baseline data was collected on the distribution, abundance, diversity, biogeography and connectivity of chemosynthetic communities and surrounding faunal assemblages.

Henderson Ridge Mid-South (AT401)

Area

Henderson Ridge Mid-South (AT401); Gulf of Mexico

Overview

Purpose

The dive was within a proposed Flower Garden Banks National Marine Sanctuary expansion zone, and so had significant management implications. The dive explored the main ridge in this area, where multibeam surveys by the NOAA Ship Okeanos Explorer identified five possible locations of methane bubble plumes. The area showed high habitat suitability for deep-sea corals in models, so observations supported goals of the Southeast Deep Coral Initiative (SEDCI). ROV exploration of these features will also help determine the geological composition and origin of this area. Additionally, baseline data was collected on the distribution, abundance, diversity, biogeography and connectivity of chemosynthetic and coral communities, as well as surrounding faunal assemblages.

Green Canyon Area, St. Tammany Basin (GC939)

Area

Green Canyon Area, St. Tammany Basin (GC939); Gulf of Mexico

Overview

Purpose

The dive site was located near to a proposed Flower Garden Banks National Marine Sanctuary expansion zone, as well as a Habitat Area of Particular Concern (HAPC) proposed by the Gulf of Mexico Fishery Council. Extensive previous exploration and the presence of a pipeline in the proposed areas limited potential dive locations within proposed areas. Additionally, several methane bubble plumes and potential hard grounds detected approximately five kilometers south during multibeam surveys by the NOAA Ship Okeanos Explorer resulted in the dive being planned outside of proposed areas for management. Despite this, baseline data collected on the distribution, abundance, diversity, biogeography and connectivity of chemosynthetic communities and surrounding faunal assemblages, as well as the geological composition and origin of this area, will have implications for the management of these areas.

KC 560

Area

KC 560; Gulf of Mexico

Overview

Purpose

The dive site was a BOEM seismic anomaly suspected to be a mud volcano with hydrocarbon seepage. The primary objective for this dive was to acquire baseline information on the distribution and abundance of benthic fauna, in particular chemosynthetic habitats. This will aid in gaining insight into the diversity, biogeography, and connectivity of these communities. Improving the geological understanding of the composition and origin of the area was also of importance.

Wreck 15725 (KC530)

Area

Wreck 15725 (KC530); Gulf of Mexico

Overview

Purpose

This dive investigated a side scan sonar target thought to represent an archaeological site and related debris. As this was the first time the site was investigated, it was expected that a visual reconnaissance would be conducted, as well as an experimental mosaic survey, and inspection of diagnostic artifacts, features, and biological inhabitants. A survey of the debris field was also expected. However, upon reaching the site of the wreck, only recent human debris was observed. As a result, it was decided that the benthic portion of this dive would be shortened to accommodate midwater exploration at depths of 1000m, 900m, 800m, 700m, 600m, 500m, 400m and 300m.

Tunica Mound (GB299)

Area

Tunica Mound (GB299); Gulf of Mexico

Overview

Purpose

The dive lies within a proposed Flower Garden Banks National Marine Sanctuary expansion zone as well as within a proposed Habitat Area of Particular Concern (HAPC). The dive track climbed a series of terraces in the northern section of this area, and then headed west along a ridge. This maximized chances of encountering exposed characteristic hard substrate and coral communities in this area. The primary objective for this dive was to acquire baseline information on the distribution and abundance of benthic fauna, gaining insight into the diversity, biogeography, and connectivity of these communities. ROV exploration of this area will help determine the geological composition and origin of this area. Information gained has management implications.

Penchant Basin (GC276)

Area

Penchant Basin (GC276); Gulf of Mexico

Overview

Purpose

The dive site was located in a geologically active area where a number of BOEM seismic anomalies were detected, including oil and seeps. Additionally, surveys by the NOAA Ship Okeanos Explorer in 2012 and 2014 detected a number of gas plumes, indicative of possible chemosynthetic habitats. The primary objective for this dive was to acquire baseline information on the distribution and abundance of benthic fauna, in particular at chemosynthetic habitats and for corals. This aided in gaining insight into the diversity, biogeography, and connectivity of these communities, which has management implications. Improving the geological understanding of the composition and origin of the area was also of importance.

Penchant Basin (MC796)

Area

Penchant Basin (MC796); Gulf of Mexico

Overview

Purpose

The dive target was within a proposed Flower Garden Banks National Marine Sanctuary expansion zone. The area showed high habitat suitability for deep-sea corals in models, so observations support goals of the Southeast Deep Coral Initiative (SEDCI). The primary objective for this dive was to acquire baseline information on the distribution and abundance of benthic fauna, including corals such as Lophelia. This aided in gaining insight into the diversity, biogeography, and connectivity of these communities, which has management implications. Improving the geological understanding of the composition and origin of the area was also of importance. Two exploratory 10-minute midwater transects were undertaken at 400 m and 300 m depths.

Dauphin Dome (MC388)

Area

Dauphin Dome (MC388); Gulf of Mexico

Overview

Purpose

The dive target was within a proposed Flower Garden Banks National Marine Sanctuary expansion zone. We targeted the western-edge of the dome that had a number of BOEM seismic anomalies and water-column bubble targets detected by the NOAA Ship Okeanos Explorer. The primary objective for this dive was to acquire baseline information on the distribution and abundance of benthic fauna, including chemosynthetic communities and corals. This aided in gaining insight into the diversity, biogeography, and connectivity of these communities, which has management implications. Improving the geological understanding of the composition and origin of the area was also of importance. Following the benthic portion of this dive, there were four exploratory midwater transects (900m, 700m, 500m, 300m).

Horn Dome (MC036)

Area

Horn Dome (MC036); Gulf of Mexico

Overview

Purpose

The dive target was within a proposed Flower Garden Banks National Marine Sanctuary expansion zone. We targeted the northwestern-edge of the dome that had a number of BOEM seismic anomalies and watercolumn bubble targets detected by the NOAA Ship Okeanos Explorer. The primary objective for this dive was to acquire baseline information on the distribution and abundance of benthic fauna, including chemosynthetic communities and corals. This aided in gaining insight into the diversity, biogeography, and connectivity of these communities, which has management implications. Improving the geological understanding of the composition and origin of the area was also of importance.