ACCESS NUMBER: 39187 

STUDY TITLE: Deepwater Program: Investigations of Chemosynthetic Communities 

on the Lower Continental Slope of the Gulf of Mexico (Chemo III) 

REPORT TITLE: Investigations of Chemosynthetic Communities on the Lower 

Continental Slope of the Gulf of Mexico, Interim Report 2 

CONTRACT NUMBER: 1435-01-05-39187 (M05PC00018) 

SPONSORING OCS REGION: Gulf of Mexico 

APPLICABLE PLANNING AREA: Central 

FISCAL YEARS OF PROJECT FUNDING: 2005; 2006; 2007; 2008, 2009 

COMPLETION DATE OF REPORT: August 2009 

COSTS: FY 2005 - $842,977; FY2006 - $798,028 

PROJECT MANAGER: James M. Brooks, Ph.D. 

AFFILIATION: TDI-Brooks International Inc 

ADDRESS: 1902 Pinon Dr, College Station, TX 77845 

PRINCIPAL INVESTIGATORS*: Brooks, J. M.1, C. Fisher2, H. Roberts3, B. Bernard1, I. 

McDonald4, R. Carney3, S.Joye5, E.Cordes6, G. Wolff1, L. Gehring2 (

1 TDI-Brooks 

International Inc, 2

 The Pennsylvania State University, 3 Louisiana State University, 4

Texas A&M University – Corpus Christi, 5 The University of Georgia, 6 Harvard 

University) 

KEY WORDS: Gulf of Mexico, chemosynthetic communities, habitat, AUV, ROV, 

submersible, biology, photography, tubeworms, mussels, bacterial mats, education, 

population dynamics, food web, life histories, biodiversity and biogeography 

BACKGROUND: The largest oil reserves in the continental United States are found in 

the Gulf of Mexico (GOM). The Mineral Management Service (MMS) is responsible for 

overseeing the responsible extraction of these natural resources. By the early 1980s, 

energy companies had developed the technology to explore and extract oil and gas in 

waters up to 1,000 m deep and have continued to develop the technology to extract oil 

and gas from deeper water and now have the capability to drill oil wells in all water 

depths in the GOM Outer Continental Slope (OCS). 

During the mid to late 1980s, MMS contracted with the Geochemical and Environmental 

Research Group (GERG) at Texas A&M University (TAMU) to collect animals from 

areas of the deep sea floor associated with active oil and gas seeps. Bush Hill, a site 

that became one of the best studied seep sites in the world, was populated with giant 
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tubeworms and mussels, which had only recently been discovered at deep-sea 

hydrothermal vents in the Pacific Ocean. Since that time similar (but different) coldseep and hydrothermal-vent communities have been discovered in many different 

geological settings in the world’s oceans. 

Over the last 20 years these animals and communities have been studied at moderate 

depths in the GOM, along with the geology, geochemistry, and microbiology that allows 

them to flourish. The hydrocarbon seep communities in less than 1,000 m on the upper 

Louisiana slope of the GOM are the most intensively studied and most understood of 

any deep-sea cold-seep communities in the world. The basic biology of the dominant 

animals, their life histories, and the biodiversity and biogeography of the seep and coral 

communities on the upper Louisiana slope is now understood. The successional 

processes that lead to the eventual development of coral communities on carbonates 

created during periods of active hydrocarbon seepage is understood. Also discovered 

are new communities, such as the ice worms that inhabit methane ice and the mussels 

that ring the Brine Pool NR-1. 

Although several GOM hydrocarbon seep sites at depths greater than 1,000 m have 

been visited by scientists, only a single site has been the focus of more than a few 

exploratory dives. This site, at 2,200 m in Alaminos Canyon, has lush communities of 

tubeworms and mussels that are reminiscent of the shallower sites that are well known. 

However, the underlying geology and almost all of the species present are different. 

Preliminary studies indicate that the structure of the communities associated with the 

tubeworms and mussels is also quite different. The normal “background” fauna are 

different at this depth, and different patterns of interaction between these animals and 

the seep specific animals are expected. 

OBJECTIVES: The primary purpose of this research is to discover and characterize 

the sea floor communities that live in association with hydrocarbon seepage and on 

hard ground in the deep GOM. The sites studied are in areas energy companies will 

soon drill for oil and gas. Advances in understanding and knowledge of the ecology of 

this deep community and the types of communities that exist at depths between 1,000 

and 2,200 m are the goals of this contract. 

DESCRIPTION: Preparation for this program began in the fall of 2005, when Harry 

Roberts began to study a variety of types of information that would help discover new 

hydrocarbon seep and hard-ground communities in the deep GOM. Information was 

gathered from thousands of cores collected by the TDI-Brooks International, Inc. group, 

satellite images of persistent oil slicks on the surface of the Gulf, and extensive 

collections of geophysical data and maps of the sea floor that were made available for 

this project by the MMS. Fourteen sites were identified with a high potential to host lush 

chemosynthetic and/or deep-water coral communities. 

The Reconnaissance Cruise (RC) was conducted on the TDI-Brooks research vessel 

R/V GYRE from March 11-25, 2006 and was the initial cruise conducted for this 

contract. The cruise was completed in two week-long legs with an interim port call in 
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Venice, LA. Leg I (March 11-18, 2006) was dedicated to drift camera work to survey the 

sea-bed at selected sites. Leg II (March 19-25, 2006) involved both drift camera and 

trawling/box core work efforts. Thousands of pictures of the sea floor were taken at 

locations identified by Roberts and his team. Some sites revealed little except a muddy 

sea floor. At most of the sites there was strong evidence of seepage, and at least 

scattered occurrence of the types of animals expected at seep sites. In one case there 

were abundant soft corals, and at a few, there were large communities of seep animals. 

Based on the reconnaissance cruise report, the images of the sea floor, previous 

knowledge of the geophysics and geochemistry of the sites, and a desire to explore 

over a wide depth and geographic range, the cruise and dives on the Deep 

Chemosynthetic Community Characterization (DCCC) expedition were planned and 

completed in May 2006. The DCCC cruise was conducted on the Wood's Hole 

Oceanographic Institute (WHOI) research vessel R/V ATLANTIS and the ALVIN Deep 

Submergence Vehicle (DSV) from 7 May – 2 June 2006. 

From June 4 - July 6, 2007, TDI-Brooks' project team conducted a month long ROV 

cruise at deep-water seep and hardground sites in the lower continental slope of the 

GOM. The project utilized the NOAA ship the R/V RON BROWN and the JASON-II

ROV from Woods Hole Oceanographic Institute (WHOI). Data were collected by the 

geologists, geochemists, microbiologists, physiologists, and ecologists in the scientific 

party. 

SIGNIFICANT CONCLUSIONS:

• The number of survey photos captured with the bottom in view (BIV) was 10,922. 

• Site characterization and evaluation was completed on 24 sites. 

• Multiple dives were made at four sites and the geology, geochemistry, 

microbiology and biology of the sites thoroughly characterized. 

• Longer-term studies were established at these sites to determine growth rates of 

some of the animals, monitor for visitation by mobile deep-sea fauna such as 

larger fishes and crabs, and follow the fine scale changes in seepage patterns 

and community composition (Figure 1). 

• A camera dedicated to taking down-looking pictures was used to construct 

mosaics of any new animal communities discovered. 

• Push cores were collected for geological, geochemical, and microbial analyses 

and for the study of some of the tiny animals that may live between the sand 

grains at the deep seep sites. 

• A chemical analyzer was used to characterize new habitats. 

• Collections for study of the larger animals that live at the sites was begun. 

• Communities with full mosaics were revisited and chemical analyzers used to 

characterize the chemistry in and around individual animals identified in the 

images. 

• Quantitative collections of other tubeworm communities, mussel beds, and clam 

beds were made using specialized collection tools built specifically for this task. 

• Ten nighttime trawls were completed. 
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• Traps and cameras were used to capture and identify the visitors to the seep and 

coral communities being studied to aid in characterizing the more mobile fauna 

around the sites. 

• A rotary camera, left on the bottom for up to a year, is housed in a special glass 

tube and periodically “wakes up” to take 12 consecutive pictures as it rotates on 

a turntable. 

• More than 14,000 down-camera and 400 macro images were recorded. 

• Acoustic Doppler Current Profilers (ADCP) were operated on station and with the 

ship underway to obtain an integrated picture of current direction and velocity in 

the upper 1,000 m of the water column. 

Autonomous Underwater Vehicle (AUV) 

Sites AT340, GC852, WR269, and AC601 were mapped in great detail using the C&C 

Technologies Autonomous Underwater Vehicle (AUV) in February 2007. The AUV is 

equipped with instrumentation for collecting high-resolution multibeam bathymetry, chirp 

sonar subbottom profiles, and side-scan sonar swaths. These data are well constrained 

with excellent navigation and the data sets are acquired as the AUV travels at a 

constant height, 40 m, above the seabed. The data sets were used during the 2007 

cruise. 

STUDY PRODUCTS: TDI-Brooks International Inc. 2009. Investigations of 

Chemosynthetic Communities on the Lower Continental Slope of the Gulf of Mexico. 

An interim report 2 for the U.S. Dept of the Interior, Minerals Management Service Gulf 

of Mexico OCS Region, Metairie, LA. OCS Study MMS 2009-046. 367 pp. 

TDI-Brooks International Inc. 2007. Investigations of Chemosynthetic Communities on 

the Lower Continental Slope of the Gulf of Mexico. An interim report 1 for the U.S. Dept 

of the Interior, Minerals Management Service Gulf of Mexico OCS Region, Metairie, LA. 

Contract No. 1435-01-05-39187. 338 pp. 

Erik E. Cordes, Susan L. Carney, Stephane Hourdez, Robert S. Carney, James M. 

Brooks, Charles R. Fisher. 2007. Cold seeps of the deep Gulf of Mexico: Community 

structure and biogeographic comparisons to Atlantic equatorial belt seep communities. 

Deep-Sea Research I 54 (2007) 637–653. 

TDI-Brooks International Inc. 2006. Investigations of Chemosynthetic Communities on 

the Lower Continental Slope of the Gulf of Mexico. Reconnaissance Cruise Report for 

the U.S. Department of the Interior, Minerals Management Service Gulf of Mexico OCS 

Region, Metairie, LA. Contract No. 1435-01-05-39187. 58 pp. 

TDI-Brooks International Inc. 2006. Investigations of Chemosynthetic Communities on 

the Lower Continental Slope of the Gulf of Mexico. Deep Chemosynthetic Community 

Characterization Cruise Report for the U.S. Department of the Interior, Minerals 

Management Service Gulf of Mexico OCS Region, Metairie, LA. Contract No. 1435-01-

05-39187. 225 pp. 
ACCESS NUMBER: 39187 

 

TDI-Brooks International Inc. 2007. Investigations of Chemosynthetic Communities on 

the Lower Continental Slope of the Gulf of Mexico. Deep Chemosynthetic 

Reconnaissance II (DCR2) Post-Cruise Report for the U.S. Department of the Interior, 

Minerals Management Service Gulf of Mexico OCS Region, Metairie, LA. Contract No. 

1435-01-05-39187. 317 pp. 

Erik E. Cordes, Susan L. Carney, Stephane Hourdez, Robert S. Carney, James M. 

Brooks, Charles R. Fisher 2007. Cold seeps of the deep Gulf of Mexico: Community 

structure and biogeographic comparisons to Atlantic equatorial belt seep communities. 

Deep-Sea Research I 54:637–653. 

Charles Fisher, Harry Roberts, Erik Cordes and Bernie Bernard 2007. Cold Seeps and 

Associated Communities of the Gulf of Mexico. Oceanography Vol 20 Num 4, pp 68-79. 

Harry Roberts, Robert Carney, Mathew Kupchik, Charles Fisher, Kim Nelson, Erin 

Becker, Liz Goehring, Stephanie Lessard-Pilon, Guy Telesnicki, Bernie Bernard, James 

Brooks, Monika Bright, Erik Cordes, Stephane Hourdez, Jesse Hunt Jr., William Shedd, 

Gregory Boland, Samantha Joye, Vladimir Samarkin, Meaghan Bernier, Marshall 

Bowles, Ian MacDonald, Helge Niemann, Cindy Petersen, Cheryl Morrison, Jeremy 

Potter 2007. Alvin Explores the Deep Northern Gulf of Mexico Slope. EOS Vol 88 (35), 

28 August 2007, pp 341–348. 

*

 P.I.’s affiliation may be different from that listed for Project Managers. 
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Chemosynthetic Sites visited 2006 
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Site locations of JASON dives