Southeast US and Bahamas, Leg 2

Vessel: NOAA Ship Okeanos Explorer; Expedition Dates: October 31, 2019 to November 20, 2019

Ports: Miami, FL to Key West, FL

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

From October 31 to November 20, 2019 the NOAA Office of Ocean Exploration and Research (OER) conducted the 2019 Southeastern U.S. Deep-sea Exploration remotely operated vehicle (ROV) and mapping cruise (EX1907) from Miami, Florida, to Key West, Florida. Twelve ROV dives were completed, and over 12,700 square kilometers were mapped during this expedition. ROV dive operations supported the expedition objectives, including characterizing bottom fish and precious coral habitats, deep-sea coral habitats, seamounts, and fracture zones. During each dive, the ROVs descended to the seafloor and then moved from waypoint to waypoint, documenting the geology and biology of the area. Onboard and shore-based scientists identified encountered organisms to the lowest taxon possible based on data available during real-time assessment.

Blake Plateau South

Area

Blake Plateau South; Southeast U.S. Continental Margin, offshore Florida, Georgia, South Carolina and North Carolina

Overview

Date:	November 01, 2019
Max Depth:	870 Meters
Bottom Time:	6 Hours 50 Minutes 33 Seconds

Purpose

This site was first mapped during EX-19-03 L1 earlier in 2019. Seafloor bathymetry revealed a series of mound features and larger north/south trending ridges/escarpments. Characterizing newly acquired multibeam bathymetry is a priority for OER and its partners. These type of seafloor features can provide suitable habitat for deep-sea coral and sponge communities and their associates. This location is just inside the HAPC and will help provide foundational data needed by the scientific community. It was proposed as a dive site on EX-19-03-L2 but was dropped after the community decided to dive further to the west.

Stetson Mesa East

Area

Stetson Mesa East; Southeast U.S. Continental Margin, offshore Florida, Georgia, South Carolina and North Carolina

Overview

Date:	November 02, 2019
Max Depth:	826 Meters
Bottom Time:	9 Hours 5 Minutes 30 Seconds

Purpose

Dive location was a placeholder for EX1906 data. This ridge seems to mark the eastern extent of the Million Mounds area. Dive will help characterize EX1906 mapping data. Based on bathymetry data, this ridge seems to be topped with mound features. This area is part of a Habitat Area of Particular Concern (HAPC) and is a priority for regional managers. This dive is planned in an area that was recently mapped and contains interesting seafloor features that warrant further exploration and characterization.

Stetson Mesa West

Area

Stetson Mesa West; Southeast U.S. Continental Margin, offshore Florida, Georgia, South Carolina and North Carolina

Overview

Date:	November 03, 2019
Max Depth:	809 Meters
Bottom Time:	3 Hours 51 Minutes 34 Seconds

Purpose

These are interesting basin and ridge features to the west of the Million Mounds area. They have not been investigated and they have the potential to focus sub-seafloor groundwater seepage, expose faults, and display a biological gradient upslope. Characterizing this feature type will provide valuable information about the geologic makeup and biological communities that comprise these basin features seen in this region of the Blake Plateau.

Stetson Mound Field 01

Area

Stetson Mound Field 01; Southeast U.S. Continental Margin, offshore Florida, Georgia, South Carolina and North Carolina

Overview

Date:	November 04, 2019
Max Depth:	836 Meters
Bottom Time:	6 Hours 56 Minutes 52 Seconds

Purpose

This site was first mapped on EX1906. Site has the potential to be a suitable habitat for deep sea corals and sponges and could very likely be an aggregation of cold-water coral mounds Dives 4 and 5 are located in the same field of mound features, although the features seems to differ in morphology and sizes. These dives will compare mounds of different sizes and shapes. This area is also part of a Habitat Area of Particular Concern (HAPC) and is a priority for regional managers. Dive is planned in an area that was recently mapped and contains interesting seafloor features that warrant further exploration and characterization.

Stetson Mound Field 02

Area

Stetson Mound Field 02; Southeast U.S. Continental Margin, offshore Florida, Georgia, South Carolina and North Carolina

Overview

Date:	November 05, 2019
Max Depth:	830 Meters
Bottom Time:	2 Hours 36 Minutes 26 Seconds

Purpose

This site was first mapped on EX1906. Site has the potential to be a suitable habitat for deep sea corals and sponges and could very likely be an aggregation of cold-water coral mounds Dives 4 and 5 are located in the same field of mound features, although the features seems to differ in morphology and sizes. These dives will compare mounds of different sizes and shapes. This area is also part of a Habitat Area of Particular Concern (HAPC) and is a priority for regional managers.

Isolated Mound, Central Blake Plateau

Area

Isolated Mound, Central Blake Plateau; Southeast U.S. Continental Margin, offshore Florida, Georgia, South Carolina and North Carolina

Overview

Date:	November 06, 2019
Max Depth:	842 Meters
Bottom Time:	8 Hours 57 Minutes 21 Seconds

Purpose

Dive is located on mapping data from EX1906. As part of our OER objective to map and characterize the deep US EEZ, these dives will be used to characterize newly generated mapping data. The mound features this dive is located on are known hotspots of biodiversity on the Blake Plateau. Dive is located outside of the Stetson-Miami Terrace HAPC and will provide information regarding connectivity of deep-water communities in and outside the HAPC. Dive is planned in an area that was recently mapped and contains interesting seafloor features that warrant further exploration. Dive objective will be to characterize newly acquired mapping data.

Habitat Response 01

Area

Habitat Response 01; Southeast U.S. Continental Margin, offshore Florida, Georgia, South Carolina and North Carolina

Overview

Date:	November 07, 2019
Max Depth:	807 Meters
Bottom Time:	6 Hours 41 Minutes 22 Seconds

Purpose

The purpose of this mission is to revisit a site that was historically subject to experimental deep sea mining to search for any signs of disturbance that can still be observed long after those activities occurred. We are hoping to gain insight into what impacts can be expected should future mining activities happen at other locations. Dives 7 and 8 are regional priorities for USGS and BOEM. Main objective is to acquire modern data over an area that has historically been subject to bottom disturbances.

Miami Terrace

Area

Miami Terrace; Southeast U.S. Continental Margin, offshore Florida, Georgia, South Carolina and North Carolina

Overview

Date:	November 15, 2019
Max Depth:	564 Meters
Bottom Time:	7 Hours 27 Minutes 6 Seconds

Purpose

This dive is located separately from other deep submergence work in the area near Miami. Collecting high resolution video and sample data will help characterize interesting features in the high resolution bathymetry. Characterizing this feature type will provide valuable information about the geologic makeup and biological communities that comprise these areas near Miami. Dive location is inside the Stetson-Miami HAPC. Dive objectives will be to collect high-resolution video footage of the geologic facies and the benthic communities that inhabit the region as well as a more refined data collection of current systems.

Key Largo Deep

Area

Key Largo Deep; Southeast U.S. Continental Margin, offshore Florida, Georgia, South Carolina and North Carolina

Overview

Date:	November 16, 2019
Max Depth:	642 Meters
Bottom Time:	6 Hours 26 Minutes 59 Seconds

Purpose

This is a planned map and dive on mapping data that will be collected the night before. There is no other deep submergence work in the immediate area. This dive will connect deep submergence work further to the North off of Miami and work further to the West in the HAPC. Dive 09 will help characterize an area that has very little deep water information. It is also a logistical dive as EX1907 transits further to the west. Dive objectives will be to gather baseline information about an area that has little to no deep water work and characterize newly acquired mapping data

Pourtales Terrace

Area

Pourtales Terrace; Southeast U.S. Continental Margin, offshore Florida, Georgia, South Carolina and North Carolina

Overview

Date:	November 17, 2019
Max Depth:	404 Meters
Bottom Time:	8 Hours 8 Minutes 48 Seconds

Purpose

Dive 10 is planned on features that could be a suitable habitat for deep sea corals and sponges. Dive 10 will occur in the Pourtales Terrace HAPC and is a priority for regional managers. Planned dive track will cross over in and out of the HAPC. Other deep submergence work in this area has confirmed the presence of deep water coral mounds. Dive is planned away from previous work.

Key West Deep

Area

Key West Deep; Southeast U.S. Continental Margin, offshore Florida, Georgia, South Carolina and North Carolina

Overview

Date:	November 18, 2019
Max Depth:	1218 Meters
Bottom Time:	6 Hours 8 Minutes 43 Seconds

Purpose

Characterizing this feature type will provide valuable information about the geologic makeup and biological communities that comprise these small mounds and escarpment. This dive will also provide valuable information about an area that very little deep submergence work in the vicinity.

Berg Bits

Area

Berg Bits; Southeast U.S. Continental Margin, offshore Florida, Georgia, South Carolina and North Carolina

Overview

Date:	November 19, 2019
Max Depth:	973 Meters
Bottom Time:	6 Hours 51 Minutes 56 Seconds

Purpose

This area was mapped on an NOAA OER/Okeanos cruise earlier this year. It contains interesting seafloor features that warrant further investigation. From an exploration standpoint, there is no other known deep submergence work in the area.