Deepwater Corals

North to Alaska!

On March 4th a trailer truck pulled out of UConn Avery Point with two containers and a winch totaling about 27,000 pounds of oceanographic gear, headed for Seattle, WA, mobilization site for NURTEC’s latest expedition – “Deepwater Exploration of Glacier Bay National Park” (GBNP) in Alaska. One container was the Center’s ROV control van and the other housed the Kraken2 ROV and tons of support gear, tools, spares etc. The mission is being led by Dr. Rhian Waller from the University of Maine and is sponsored by NOAA’s Office of Ocean Exploration and Research (OER).

Truck with NURTEC ROV gear
A trailer truck getting ready to leave UConn Avery Point for Seattle, Washington

The K2 ROV will be deployed at night off the contracted support vessel Norseman II to explore the deeper waters of the park, collect video, digital stills and select samples of deep water organisms for subsequent genetic and age data analyses. During the day SCUBA will be used to explore and sample the shallow waters of GBNP that are unique in that they support cold water corals that normally grow in much deeper water.  This phenomenon is due to freshwater runoff that is laden with brown colored tannins that block the penetration of sunlight, creating conditions similar to much deeper water.

The Norseman II support vessel
The Norseman II
Rainbow on the way to Glacier Bay
Panorama of a rainbow on the transit to Glacier Bay











The NURTEC ROV team arrived in Seattle on March 10th and began to mobilize all of the gear onto the Norseman II, before setting sail north to Alaska. The four day transit along the spectacular Inside Passage provided additional time to tweak all systems for the upcoming two-weeks of challenging dive operations. The mission began with test dives on March 18th with the first full day of ROV operations taking place the following evening with a successful dive that included collecting many deep-water coral samples.

NOAA’s OER is providing detailed, day by day Mission Logs of the expedition on its Ocean Explorer website.


March 21, 2016 Report

The K2 ROV completed the third successful dive exploring the East Arm of Glacier Bay National Park.  Deep water corals measuring 1-2 meters across were sighted on the dive.  The team is now steaming towards the West Arm for a dive in the Johns Hopkins Inlet.

The East Arm of Glacier Bay
The calm waters of the East Arm of Glacier Bay
K2 ROV on deck after a dive in Glacier Bay National Park

2015 Deep Sea Coral Exploration in the Gulf of Maine

NURTEC conducted 26 tows using its ISIS2 towed camera system from July 1-10, 2015, continuing its partnership with NOAA Fisheries Northeast Fisheries Science Center and University of Maine to explore the Gulf of Maine for Deep Sea Corals (DSC’s). The ISIS2 camera sled was equipped with both down and forward-looking hi-def video cameras and a down-looking digital still camera. For 2015 NURTEC integrated two thrusters onto the sled to provide much improved and much needed maneuverability that allowed the system to be better positioned in the rugged topography and deal with the strong currents of the Gulf of Maine. The system was operated off the RV Connecticut, which again provided the perfect support ship for this type of operation with its dynamic positioning capabilities.


This was the third expedition, funded by NOAA’s Deep Sea Coral Research and Technology Program, to explore for DSC’s in the Gulf, with each year finding new areas that support these ecologically sensitive and vulnerable, slow-growing animals that were likely much more ubiquitous in the region. In addition, some sites from previous years were revisited to assess the condition of the corals from previous surveys. Three main areas were surveyed this year: Outer Schoodic Ridge, the Mount Desert Rock area and the Georges Basin region. The following provides some highlights from this expedition.

Several areas on Outer Schoodic Ridge did appear, based on coarse resolution bathymetry, to be similar to areas previously found to support dense coral communities. Nonetheless, they turned out to be steep sediment slopes with evidence of impacts from both mobile and fixed fishing gear (e.g., tracks on sonar, displaced cobbles and boulders). One site that was revisited from a previous cruise, with dense coral and sponges on both horizontal surfaces and steep vertical walls, had a tremendous abundance of haddock. Noteworthy is that pollock was the primary gadiform species in 2014 and silver hake in 2013. All appeared to search for and capture prey amongst the structure-forming fauna, including corals. While some of this activity is due to the attraction of prey and predators to the underwater vehicle, the variation in dominant fish species observed from year to year reflects variability in the presence of particular taxa. This suggests that DSC habitat can serve as the ecological stage for multiple players depending on current conditions.

Two spectacular coral walls were discovered in the Mount Desert Rock area on this cruise, with hanging gardens of red tree coral (Primnoa), fan coral (Paramuricea) and multiple species of sponge. A very rare pom pom anenome was observed enroute to one of the vertical walls. Noteworthy here were the dense patches of sea pens (Pennatula), including many smaller size classes (i.e., assumed younger age classes), encountered in fine-grained sediment habitats interspersed between rock ledges. This was perhaps the highest density of sea pens observed throughout this project.

Finally, no corals were observed at the base of the slope stretching from Georges Bank into Georges Basin. However, Lindenkohl Knoll, that forms a northern boundary to Georges Basin, did have sparse corals in multiple locations (mostly Paramuricea) along with evidence of extensive impacts from fishing. Steep vertical rock outcrops, like those in the northern Gulf that supported dense coral gardens, were nearly denuded of fauna and exhibited marks from fishing gear (extensive markings from ground-line components). Noteworthy is that such marks stretched from the base of one outcrop to over 6 m in vertical relief. In general, Paramuricea and associated epifauna were often small and virtually all occurred in physical refugia such as cracks and crevices of outcrops and along the sediment-rock interface of large cobbles and boulders. The one exception was an approximately 2 m deep by 4-5 m wide feature in a large outcrop with dense Paramuricea.

The results of this cruise, together with data collected during previous cruises, will provide the New England Fisheries Management Council and NOAA Fisheries important information for crafting a new Coral Amendment focused on conservation of these sensitive and vulnerable species.


2014 Gulf of Maine Deep Corals Cruise

K2 ROV launched from R/V Connecticut
K2 ROV begins descent into the deep waters of Gulf of Maine (Photo credit: P. Auster)

In the summer of 2013, the National Oceanic and Atmospheric Administration’s (NOAA) National Marine Fisheries Service (NMFS) supported NURTEC to conduct an expedition to the northern Gulf of Maine to explore for the location and distribution of deep sea corals. A 14 day cruise off the RV Connecticut with the ISIS2 camera sled was conducted from 11-24 July 2013 and completed 40 camera tows in four areas (western Jordan Basin, Mount Desert Rock-Outer Schoodic Ridges, Blue Hill Bay, and off Monhegan Island). Deep sea corals were present at 15 stations, sea pens at 20 stations and sponge fauna at 29 stations (More info).

Click here for Photo Gallery

The value of this survey was the speed at which the ISIS2 could be deployed to maximize the number sites that could be visited to provide presence/absence information on the distribution of corals and other important invertebrates. The limitations of the ISIS2, however, were that since it had no thrusters to control its direction, it was a the mercy of the ship’s motion and the currents, not being able to stop and get close-up imagery of any of the organisms. Further, the system had no capability to physically sample any of the organisms for important genetic and taxonomic analyses. In July, 2014 NMFS supported a 15 day mission to return to the Gulf of Maine with the Kraken2 (K2) remotely operated vehicle (ROV) to further survey and sample the sites that supported deep sea corals, sea pens and sponges.

Pollock amass in light of the K2 ROV.  The deepsea corals seen here provide a diverse habitat and abundance of food for benthic fishes. (Image courtesy of Gulf of Maine Deep Sea Coral Science Team 2014/NURTEC-UConn/NOAA Fisheries/UMaine)
Pollock amass in light of the K2 ROV. The deepsea corals seen here provide a diverse habitat and abundance of food for benthic fishes. (Image courtesy of Gulf of Maine Deep Sea Coral Science Team 2014/NURTEC-UConn/NOAA Fisheries/UMaine)
Map of N. Gulf of Maine Deep Coral Sites

The expedition utilized the R/V Connecticut as a support ship. It is the ideal platform to support ROV operations due to its dynamic positioning system, low freeboard and ample deck space to support the K2 ROV system comprised of the ROV, a winch for its 4000 feet of tether, a hydraulic power unit to drive the winch, and a 20 foot control van where the ROV is controlled at the direction of scientists and pilots. Despite two days of unworkable weather the NURTEC team was able to conduct 21 dives, averaging 9.8 hours in the water per day working at an average depth of 204 meters (669 feet). The K2 collected over 100 hours of high definition video and 7273 high resolution digital still images from its two cameras. In addition, the K2 collected a significant number of deep sea corals, sponges and sea pens for analyses of populations genetics, reproductive histology, and for voucher specimens at the Smithsonian Institution’s National Museum of Natural History. The genetics will provide important information on the relationship of these deep sea corals to other populations existing further offshore, while the morphological analyses will provide evidence of the dynamics of reproductive condition of these animals. Video will be used to assess habitat requirements of key species, variation in size structure of corals, and the functional role of coral and sponge taxa as fish habitat. This information, will provide NOAA and the New England Fishery Management Council with very important guidance for future management decisions on these vulnerable marine ecosystems.

In the News

2013 Gulf of Maine Corals

Imaging Surveys of Northern Gulf of Maine and Jordan Basin Habitat Areas for Deep-sea Corals and Sponges

Dive operations


Schoodic Ridges - Mount Desert Rock AreaFor this project NURTEC provided designed and developed a new towed video system to support seafloor imaging surveys in the northern Gulf of Maine.  The project is based on a collaborative pre-proposal (Auster, Packer, Nizinski, Bachmann and Stevenson) to the NOAA Deep Sea Coral Program and draft text by this same group for a deep sea coral amendment to the New England Fishery Management Council.   The project addresses NOAA’s long-term mission Goal #3 focused on “Healthy Oceans.”  In particular, research and information products that result from this deep sea coral survey effort will directly inform NOAA Fisheries and the New England Fisheries Management Council and improve conservation and sustainable use of “marine fisheries, habitats, and biodiversity …”.


Underwater Technology Development

ISIS2 towed system

A significant engineering effort was implemented to accomplish project goals for collecting high resolution seafloor imagery at a large number of stations in the steep topographic settings where corals occur in the northern Gulf of Maine.  The Instrumented Seafloor Imaging System (ISIS2) was developed to operate via an electro-optic cable to support high definition and standard definition video cameras, movable lights on pan-tilt units, a digital still camera with electronic flash and a sector scanning sonar.  The operational objective was to produce a real time “flyable” vehicle that would provide the pilot with real-time imagery with which to control the depth off bottom via a winch (y-axis movement) and to combine this with the dynamic positioning of the surface support vessel (x-axis movement along the seafloor) to conduct near bottom transects in the precipitous topography of the northern Gulf.

Operations Summary

A 14 day cruise off the RV Connecticut with the ISIS2 camera sled was conducted from 11-24 July 2013 and completed 40 camera tows in four areas (western Jordan Basin, Mount Desert Rock-Outer Schoodic Ridges, Blue Hill Bay, and off Monhegan Island). Deep sea corals were present at 15 stations, sea pens at 20 stations and sponge fauna at 29 stations.

Results to Date

tow10-114bump-03Geo-referenced data on camera tow locations and nominal presence-absence of target fauna have been submitted to the NOAA Deep Sea Coral Database.  A post-cruise review of selected still imagery produced a set of initial identifications of coral taxa for use in analysis of video imagery.  A protocol for throughput of video imagery, selecting and labeling frame-grabs, data types (e.g., taxonomic resolution, habitat classification), data handling (data set structure and storage), and linking to navigation data has been developed at NMFS Sandy Hook.  Detailed extraction of data from video imagery is ongoing.  A subset of transects has been selected for initial analyses in order to identify limitations based on image and taxonomic resolution.  An initial report focused on the occurrence of coral gardens in the Gulf of Maine, a direct result of this work, has been published in the peer-reviewed journal Biodiversity.  This project also led to a collaboration with the Ecosystem Monitoring group of NEFSC that focused on producing multibeam maps of seafloor bathymetry at two of our primary survey areas from the NOAA Ship Okeanos Explorer, September 2013 ECOMON cruise.  These maps will provide invaluable information to guide future investigations of these topographically challenging deep sea coral habitats.  An quick-turnaround publication was generated by the research team:


Peter J. Auster, Morgan Kilgour, David Packer, Rhian Waller, Steven Auscavitch & Les Watling (2013) Octocoral gardens in the Gulf of Maine (NW Atlantic), Biodiversity, 14:4, 193-194, DOI: 10.1080/14888386.2013.850446

ROV Support for the Lophelia II Expedition

Corals at Ram Powell
Deepwater corals and anemones found on Ram Powell,   a deepwater oil platform in the Gulf of Mexico. Image courtesy of the Lophelia II 2012 Expedition, NOAA-OER/BOEM.

Lophelia II 2012: Deepwater Platform Corals was a 12 day mission in the Gulf of Mexico sponsored by the Department of the Interior’s Bureau of Ocean Energy Management (BOEM) and NOAA.  NURTEC provided its remotely operated vehicle, the Kraken2 (K2), that worked off from the research vessel the Brooks McCall, operated by TDI-Brooks.  The mission was called Lophelia II after the deep-water coral Lophelia pertusa and focused on understanding the ecology of deep water corals and other invertebrates that inhabit oil and gas platforms in the Gulf of Mexico.

The expedition included lengthy, challenging yet successful ROV dives at four oil platforms and one subsea installation off the Louisiana, Mississippi, and Alabama coastline.  K2 was used to conduct thorough video and photographic surveys of coral and other invertebrate communities living on the subsea structure of the platforms, extending as deep as 1000m.    K2 was also used to collect biological specimens for museum display and genetic analysis as well as seawater and sediment samples for related ecological parameters. One of the mission highlights was the discovery of a new depth record for Lophelia at 799m on the Ram Powell platform.  Click here for more information.

Florida Shelf Edge Exploration II

Pink Stylaster corals
Pink Stylaster corals (Photo credit: CIOERT Research Team)

From September 12 to September 30, 2011, members of NURTEC’s remotely operated vehicle (ROV) operations team collaborated with the Cooperative Institute for Ocean Exploration, Research and Technology (CIOERT) and partner scientists aboard the NOAA vessel Nancy Foster to conduct an undersea exploration of Florida’s deepwater coral ecosystems.  The objectives of this expedition were to survey these shelf-edge habitats and assess abundance and diversity of reef fishes, corals, and other associated invertebrates.  While some areas were revisited from previous years, the team also explored new sites along Pulley Ridge and Pourtalѐs Terrace.


Kraken2 ROV
NURTEC’s Kraken2 ROV (Photo credit: Andy David, NMFS)

The science party utilized an array of ocean technologies including CTD, MOCNESS, multi-beam sonar to identify potential hard-bottom targets of mesophotic coral reefs and NURTEC’s ROV, Kraken2, to ground-truth these areas of interest with high definition video, digital still photography, and sample collection.  For the mission, Kraken2 was equipped with an array of custom designed sampling systems including a HD video camera, four additional SD cameras for a variety of viewpoints, a down-looking digital still camera for conduction quantitative photo transects, forward and down-looking paired lasers for sizing objects, a six function manipulator with cutting claw for sample collection, suction sampling tube and eight bucket array, auto-indexing quiver array for biota collection.


sampling coral
Kraken2 ROV collecting coral sample with manipulator
and suction hose (Photo credit: CIOERT Research Team)

Over the course of sixteen scheduled dive days, a total of 26 dives were conducted ranging in depth from less than 200 meters to 850 meters water depth.  The opportune weather conditions, cooperative effort of science, ship and ROV team, and performance of Kraken2 ROV produced hundreds of hours of undersea video, thousands of digital photos, and wide array of biological specimens collected for taxonomy, genetic sampling, and medical research.  In summary, the research cruise was a success and the resulting data/scientific insight will help assess the efficacy of establishing marine protected areas and understanding coral/fish associations.

For more information about the FLOSEE II Expedition, please visit FLOSEE II: Exploring and Mapping Shelf Frontiers off South Florida.