**NOAA Office of Ocean Exploration: Quick Look Report FY2003**

# Basin: Gulf of Mexico

**Expedition: Northern Gulf of Mexico Deep-Sea Habitats**

**Project: The Occurrence and Ecology of Deep-Water Corals and
Associated Communities**

The following Quick Look Report provides an initial overview of the
accomplishments achieved on project number OE_2003_011: The occurrence
and ecology of deep-water corals and associated communities. This
project was one of three projects supported by the NOAA Office of Ocean
Exploration (OE) during the *Northern Gulf of Mexico Deep-Sea Habitats
Expedition*.

***[I. GENERAL OVERVIEW:]{.underline}***

*[Project Title:]{.underline}* The occurrence and ecology of deep-water
corals and associated communities

*[Principal Investigator:]{.underline}* Will Schroeder (University of
Alabama)

*[Chief Scientist:]{.underline}* Sandra Brooke (University of Oregon)

> Co-PI Julie Olson (University of Alabama)

*[Primary Equipment:]{.underline}*

> Vessel: NOAA Ship RONALD H. BROWN, a 274 ft research vessel based in
> Charleston, SC.
>
> ROV: Innovator heavy work class ROV owned and operated by Sonsub, Inc.
>
> Tracking: Sonardyne tracking system linked with WinFrog positioning
> system
>
> Multibeam: Seabeam 2112

*[Partners:]{.underline}*

-   University of Alabama

-   University of Oregon

-   NOAA -- Office of Ocean Exploration

-   Texas A&M University

-   Sonsub, Inc.

-   C&C Technologies

*[Area of Operation:]{.underline}*

![](media/image1.jpeg){width="5.0in" height="3.571527777777778in"}

***[II. Summary:]{.underline}***

*[Overview:]{.underline}* This project was designed to explore for
deep-water corals, specifically *Lophelia pertusa*, which is potentially
widely distributed and associated with very site-specific conditions
conducive to colonization and growth. Unlike the large *Lophelia* reefs
found in the South Atlantic Bight, the information available indicates
that the colonies in this region exist as scattered thickets anchored on
hard carbonate substrate found in association with relict hydrocarbon
seeps. If so, we may be witnessing the early stages of *Lophelia
pertusa* coral reef development. Given the expansion of the oil and gas
industry in the northern Gulf of Mexico, it is critical that we locate,
map, and characterize these areas, and undertake comprehensive efforts
to learn more about their biology and ecological function -- the
foundation for developing sound management strategies to protect these
fragile resources. This expedition brought together scientists with
knowledge and expertise in geology, coral biology, and ecology to begin
an initial investigation of suspected sites. Several of the scientists
also are skilled in seafloor mapping and GIS, an important element of
exploratory science.

Using a remotely operated vehicle (ROV), the *Innovator*, owned and
operated by Sonsub Inc. of Houston, TX, we conducted a total of 7 dives,
collecting 20 hours of video tape, 30 digital still images, and samples
of water (2 Niskin bottles), sediment (3 cores), rocks (5), and corals
(10 branches of *Lophelia pertusa*, 1 branch of *Madrepora oculata* and
7 cup corals). We also collected a species of crab *Eumunida picta*,
which had not previously been described for the Gulf of Mexico, 2
species of unidentified anemone at VK862, and several samples of
octocorals for identification. We conducted multibeam mapping while in
transit between sites for a total of **X km**, which will be used to
identify additional areas of interest. We also conducted multibeam
mapping at Mississippi Canyon site MC885 and GC354 on a predetermined
survey grid to generate baseline maps to guide future exploration. All
of this information builds on data that we have been collecting in this
region for years using manned submersibles and other sampling
techniques. However, the *Innovator* provided an opportunity to collect
samples from deep-water areas where we have never sampled before.
Specifically, we were successful in gathering samples of *Lophelia
pertusa* and other deep-water corals, as well as sediment samples that
will help us establish a correlation between the substrate and the
corals. These samples also will be invaluable for complementary efforts
to learn more about associated fauna, hydrocarbon seepage, and microbial
activity.

*[Schedule:]{.underline}*

Sep 21 - Depart Panama City FL 1400 hrs

Sep 22 - Project number OE_2003_011: Viosca Knoll site VK826 (day lost
due to equipment malfunction)

Sep 23 - Project number OE_2003_011: Viosca Knoll site VK862/906/907

Sep 24 - Project number OE_2003_011: Viosca Knoll site VK826

Sep 25 - Project number OE_2003_011: Green Canyon site GC354

Sep 26 - Project number OE_2003_074

Sep 27 - Project number OE_2003_074

Sep 28 - Project number OE_2003_074

Sep 29 - Project number OE_2003_074

Sep 30 - Project number OE_2003_011: Mississippi Canyon site MC885

Oct 1 - Project number OE_2003_011: Mississippi Canyon site MC118 (day
lost due to weather)

Oct 2 - Arrive Gulfport MS 0900 hrs

Oct 3 - Open House

*[Project Objectives:]{.underline}*

-   Document coral habitat through video, stills, and specimens

-   Document bottom currents using a ADCP deployed from the ROV

-   Collect samples of associated fauna using manipulator and suction
    sampler

-   Document geology by collecting sediment samples - push cores

*[Key Findings:]{.underline}*

## Geology and morphology of target areas

All of our target areas included topographic features with various
degrees of relief and quantities of exposed carbonate. The overlying
sediment was composed of fine silts, and in some places also included
nodules of authigenic carbonate rock or high concentrations of dead clam
shells. The working depths of the sites ranged between 320m and 640m.
Water temperatures at these depths are approximately 7-8^o^C and
observed current speeds were \< 1kt. Visibility was equal to light
attenuation distance.

### Corals

High levels of spatial heterogeneity were observed among benthic
biological communities at all of the sites investigated. Areas of dense
epibenthic coverage were interspersed with areas of uniform sediment,
which were devoid of epibenthic fauna. Despite similarities in surficial
geology, each site supported zones of different dominant benthic
communities. We did not find large stands of *Lophelia pertusa* at sites
other than VK826; however, given the patchiness of these habitats and
the apparent zonation of community types, it is quite possible that
*Lophelia* systems also exist at the other sites, but are outside the
surveyed areas. A previously unexplored site, MC885, contained areas
with dense stands of large *Callogorgia* sp. Samples of *Lophelia,
Madrepora* and cup corals were collected for analysis of reproductive
status, and live samples of *Lophelia* will be taken to the Oregon
Institute of Marine Biology for laboratory studies on coral behavior and
physiology. Samples of water, sediment and coral mucus were collected
for examination of associated microbial communities.

### 

### Associated invertebrates

A large number of invertebrates have been observed in association with
*Lophelia* communities. The structural complexity of the coral colonies
provides habitat for small crustaceans (crabs, shrimp) and echinoderms
(Ophiuroids, crinoids, asteroids) living in the interstices of the
branches. Encrusting sponges, serpulid worms and bryozoans live on the
dead skeleton and boring organisms invade both living and dead coral.
Large octocorals also supported an associated invertebrate fauna.
Several individuals of a large fleshy ophiuroid (ID TBD) were frequently
closely associated with the octocoral trees, and small crabs and shrimp
were observed amongst the branches. Exposed carbonates were frequently
colonized by a number of sponge and coral species, which provide
structural habitat for invertebrate fauna; however endemism of
invertebrates within habitat type is unknown.

*[Initial Impressions/Characterization:]{.underline}*

At VK 862, a species of solitary anemone occurred at high densities
across large areas of the site. Occasional exposed carbonate outcrops
supported sponges and gorgonians. Only a single *Lophelia* colony was
observed at this site during the survey, although small colonies have
been observed on exposed carbonates during previous surveys (NR1
submarine). At VK826, large established thickets of live and partly live
*Lophelia* colonies were the dominant benthic features. These occurred
on exposed carbonate outcroppings and also on apparently sediment
covered substrate. We investigated an area of the NE section of the site
where high-resolution side scan sonar data indicated the presence of
dense coral thickets. We encountered a flat mud substrate devoid of
epibenthic structure and concluded that the coordinates of the SSS data
were offset and required recalculation, but that the area warrants
further exploration. The third site, GC354 had areas of large exposed
carbonate boulders, which supported communities of sponges,
scleractinians and octocorals, crinoids etc, but outside of the boulder
field near the top of the western mound, the substrate was primarily mud
and had little epibenthic community structure. At our last surveyed site
(MC885), we encountered a large patch of *Callogorgia* bushes, also on
the southern slope of the eastern mound. To the north and east of the
*Callogorgia* field, the substrate became flat areas of fine mud.

***[Accomplishments:]{.underline}***

#### ROV operations

We dove on a total of 4 different sites: VK862 (Dives 30 and 31 -- total
6 hours of video); VK826 (dives 32, 33, 34 -- total of 4 hours of
video); GC 354 (dive 36 -- 3 hours of video) and MC885 (dive 43 -- 7
hours of video). We completed 4 transect lines on the southern side of
the southwestern mound at VK862 (100m in length and 20m apart), and
another on the top of the eastern mound (150m in length and 50 m apart).
At VK826 we made collections on the southwestern flank, surveyed the top
of the mound and ran a transect grid (150m lines, 50m apart) over an
area to the Northeast of the mound. This grid did not cover the target
substrate so the grid was repositioned 100m to the east. This was also
unsuccessful and the target feature was not located. At GC354, we
deployed a current meter near the top of the western mound, surveyed the
mound area and ran a long transect (350m) from the west to the east
between the two topographic high points. We then returned to the first
area, made collections of octocorals and took photographs of fauna on
the large boulders scattered throughout the area. At MC885 we ran 2 x
200m transects across the site in a west -- east direction, and then
concentrated smaller transect lines on the western side of the site in
the *Callogorgia* fields.

#### Sampling operations

Samples of *Lophelia* were collected at VK826 and GC354. *Madrepora
oculata* was collected at MC885 along with several unidentified cup
corals. Samples of *Antipathes* sp., anemones (unidentified) and
*Eumunida picta* were collected at VK862 and octocorals, sponges and
galtheid crabs were collected at GC354. Samples of *Callogorgia* sp. and
a redeye gaper fish were collected at MC885.

#### Mapping operations

Multibeam data were collected at GC354 and MC885. Sites VK 862 and 826
had been mapped during the previous cruise. Multuibeam data was also
collected during transit between VK826 - GC354 and also during the
transits between the Flower Gardens - MC885 -- MC118.

#### Education and outreach 

The deep-water coral team participated in the tours of the Ronald H.
Brown conducted on Friday, October 3, 2003, for local media and
middleschool students. Displays of living deep-water organisms included
corals (*Lophelia pertusa*, *Madrepora occulata*, *Madracis* sp., cup
corals), a Venus fly-trap anemone, and a squat lobster (*Eumunida
picta*). Also available for discussion and examination were a sediment
core from \~1500 feet depth and bacterial colonies from deep-water
samples. The group also participated in writing material for the Ocean
Explorer website during and prior to the cruise and used the OE website
as a link for students to keep updated on the progress of the
expedition. An abstract was submitted to the Underwater Intervention
2004 conference summarizing the results of this cruise and the utility
of the Ronald H. Brown and the Sonsub Innovator ROV as a research
platform. A variety of additional talks by the PI's will also
incorporate data collected on this cruise. At least one manuscript is
expected to be produced utilizing the cruise data.

#### Web-site

Two of the daily logs were written by the PI's and information regarding
the final dive (MC885) was provided for a third daily log. A mission
plan and list of objectives, as well as a supporting article on coral
distribution and abundance, were submitted to the Ocean Explorer website
prior to the cruise.

***[Thoughts for the Future:]{.underline}***

The application of the industrial ROV to our science objectives met with
moderate success, but I believe the limitations of the system can be
overcome to create a successful union of science and industry. The
advantage of using the ROV over a submersible is the ability to run
24-hour operations and therefore ultimately cover more area. The
disadvantage is that although the ROV itself can survey quickly (\~0.5
kts.), the TMS and ship were slow and cumbersome to move. If the work is
focused on a small area this is not an issue, but for large-scale
surveys a lot of time was wasted during repositioning. The speed of
survey was greatly reduced (\~0.1 kts.) in areas with topographic
features and the ROV tether often dragged on the ground or became
tangled around boulders. This is not acceptable in a fragile ecosystem
since the tether can cause a lot of damage and time was also wasted
during tether recovery. Making specimen collections would be greatly
improved by the addition of an integrated carousel or box on the front
of the ROV, preferably constructed from some kind of insulated material
so that specimens are recovered in good condition. The size and power of
the ROV was more than sufficient for fulfilling the research objectives.
A smaller machine would have been more maneuverable in complex habitats
and less powerful thrusters would have caused less sediment disturbance.
In areas with fine silt substrate, the ROV caused such high turbidity
that it would take several minutes to clear before operations could
proceed. The ROV operations could be improved by: 1) the use of a
smaller machine 2) the addition of a dedicated collection device 3) a
crew of pilots that have experience in working with similar systems. On
a positive note, the Sonsub crew and the navigation team were willing to
help in any way and did their utmost to improve operations for us. We
were very impressed with their professionalism and see great potential
for working with this group in the future.

The priority research need for this project is continued ground-truthing
of existing mapping data. This will require large-scale surveys using an
ROV, AUV or towed camera in order to cover large areas over extended
periods of time. Submersibles are not appropriate for this task since
they have limited bottom time. Observations of faunal distribution
during this cruise indicate extreme patchiness and differences in
dominant fauna, within apparently similar habitats. Further geological
and hydrographic site characterization is needed in order to understand
what is driving these zonation patterns. As far as management of coral
ecosystems in the GOM, the only well developed *Lophelia* area we know
of is at VK826. Since there are no commercial benthic fisheries species
in the deep GOM, the reefs are assumed to be safe from trawling, however
whilst diving on VK862 a fishing trawler was observed nearby in
approximately 500m of water. The boat was not operating at the time, but
this warrants further investigation. If deepwater fisheries are
developing in the GOM, there will be an urgent need to determine extent
and distribution of coral ecosystems. Mineral Management Service have
recently awarded a contract tocollaborating groups from Oregon Institute
of Marine Biology, University of Alabama and Pennsylvania State
University. The objective of the proposal is characterization of
habitats for deepwater corals in the GOM, using JSL submersibles. There
is great potential to combine further Ocean Exploration ventures with
this contract and thereby enhance the efforts of both.

***[Appendices:]{.underline}***

A.  Milestones -- we have explored parts of some of the sites where
    coral has been reported in the GOM. VK826 is well developed and will
    be our primary study site for focused ecological research over the
    next 2 years, whilst further exploration is needed to investigate
    extent and distribution of corals at other sites in the deep GOM

B.  Data Collected

-   20 hours of digital video, of which approximately 50% might be
    useful for benthic community analysis.

-   ROV tracking information for each dive.

-   CTD data for each dive

-   Digital still (2 dives) and video grab images for each dive

-   Video annotation information on habitat type and collection
    information

-   Samples of *Lophelia pertusa* for histology and laboratory
    experiments, samples of gorgonians and anemones for identification
    and archiving, samples of coral mucus, sediment and water for
    microbial community assessment.

-   Multibeam mapping of MC885 and GC354 (VK826 and VK862 ad been
    covered on the previous cruise), plus extended single swath
    transects between sites

Dive Logs -- Taconya will provide