NOAAS Okeanos Explorer Gulf of Mexico 2017 Expedition

Gulf of Mexico 2017 was a 23-day telepresence-enabled expedition focused on acquiring data on priority exploration areas identified by ocean management and scientific communities.

Using NOAA Ship Okeanos Explorer's unique capabilities, scientists and other audiences onshore were provided with real-time video footage from deep-water areas in important, yet largely unknown, U.S.

[1] 17 ROV dives were conducted from 300 to 2,321 meters of depth to explore the diversity and distribution of deep-sea habitats and associated marine communities in the Gulf of Mexico basin.

There were also four midwater exploration dives conducted at depths of 300 to 900 meters to investigate the diversity and abundance of the largely unknown pelagic fauna.

Asphaltic and authigenic carbonate outcrops hosting large filter-feeding communities were also observed in geologically active areas.

[1] A number of the ROV dives surveyed Habitat Areas of Particular Concern (HAPCs) proposed by the Gulf of Mexico Fishery Management Council.

Based on initial observations, archaeologists believe the shipwreck likely post-dates 1830 and may have been a merchant ship built for distance over speed.

The blue curve on the graph shows the ocean temperatures measured by the conductivity-temperature-depth (CTD) sensor on the Deep Discoverer ROV during Dive 17 at Horn Dome.

Video recording of methane emissions adjacent to one of the massive hydrate deposits provided insights into seafloor gas dynamics.

[7] The only macrofauna spotted living directly on methane hydrate outcrops were ice worms, Hesiocaeca methanicola.

Map of the general expedition operating area
Fish experts on the global midwater team were blown away by the appearance of this fish from the genus Leptochilichthys . The observation placed this fish at a shallow depth of 900 meters, when typical observations place this fish squarely in the bathypelagic zone at ~2,000 meters. [ 3 ]
During Dive 7, Deep Discoverer explored an unknown shipwreck identified by the Bureau of Ocean Energy Management simply as “ID Number 15377.” .
Dive 17 explored the northwest part of Horn Dome, a salt-cored bathymetric high that had been the focus of several previous remotely operated vehicle dives.
Methane hydrate is stable to the left of the purple curve on this temperature-depth plot. Each 100-meter increase in water depth corresponds to a pressure increase of ~10 megapascals .
Pink "ice worms" are visible beneath the overhang in the center left part of this photo.