Electronic Supplementary Material
Decline in condition of gorgonian octocorals on mesophotic reefs in the
northern Gulf of Mexico: before and after the Deepwater Horizon oil spill
Peter J. Etnoyer1*, Leslie N. Wickes2, Mauricio Silva3, J.D. Dubick2, Len Balthis1, Enrique
Salgado2, Ian R. MacDonald3
1. NOAA Center for Coastal Environmental Health and Biomolecular Research, 219 Fort
Johnson Rd., Charleston, SC 29412
2. JHT, Inc. 2710 Discovery Dr., Suite 100, Orlando, FL 32826
3. Florida State University, Tallahassee, FL 32306
* Communicating author information:
Phone number: 843-789-9061
Fax number: 843-762-8700
Email: peter.etnoyer@noaa.gov
ESM- ROV Methods
Multiple pre-spill expeditions contributed to the total transect video time used in the coral health
analysis (Table 1). Beginning with MAMES in 1989 (Brooks et al. 1991), operations were
conducted aboard the ship R/V Tommy Munro using a modified Benthos RPV-2000 equipped
with a modified Sony DXC-3000 3-CCD (Photosea 3000) color video camera. All other video
was supplied from the USGS mesophotic reef fish surveys from 1997-2003 also aboard the R/V
Tommy Munro except 1997 where the R/V Suncoaster was employed. These cruises used
multiple Phantom ROVs. Through 1997-1999, a Phantom-S2 operated by the US Navy or NMFS
conducted operations and the National Undersea Research Center Phantom-DS4 outfitted with a
Nikon 950, 2-MP color video camera was used in the following years (2000-2003). In addition,
the ROV was equipped with forward-looking high-resolution still cameras from Insite Pacific
and a standard definition video camera, with 10 cm red lasers for scale
Post-spill research expeditions were conducted aboard NOAA ship Nancy Foster (August 1-8,
2010), Holiday Chouest (August 15-30, 2011), and RV Walter Smith (June 22 to July 13, 2014).
The ROVs employed for sampling were Global Explorer (2010 and 2014) and UHD Schilling
Robotics (2011). ROV dives were conducted each day that weather and currents would permit,
for the purpose of collecting biological samples, still images, and video images.
Image samples were collected on- and off-transect in all years. Cameras employed for capturing
post-spill high-definition video were Ocean Pro HD, 2-mp video camera (2010), Insite Pacific
Inc. Mini Zeus CMOS HDTV (2010), and Ocean Pro HD 3-mp video camera (2014). For highresolution in-situ documentation of polyp condition, the 2011 field effort included a digital still
camera (AquaSLR) in a deep-sea housing that was mounted on a frame that carrying two highoutput LED lamps; the array was deployed by the ROV manipulator arm. Transects were used
for abundance, density, and diversity estimates. Video framegrabs from transects in 2011 and
2014 were used for injury analysis. Calibrated lasers were employed for scale - 2 red lasers were
set at 24 cm distance in 2011, and 4 green lasers were set at 10 cm in 2014. CTD casts (Seabird
SBE 11 plus) were made at least once per site in 2014 to characterize temperature, oxygen, and
fluorescence.
The USGS historic dataset (225 min) provided the main source of pre-spill video. This was
supplemented by MAMES (70 min) at Alabama Alps. Only the 2011 NRDA dataset was utilized
for injury analyses. In total pre-spill video time, there was 92 min (22 transects) from AAR, 105
min (72 transects) on RTR/YTR, 37 min (26 transects) on CTR, and 61 min (58 transects) from
MSSR. Post-spill video times among the four sites included 140 min (31 transects) at AAR, 114
min (35 transects) at RTR/YTR, 33 min (11 transects) at CTR and 53 min (17 transects) at
MSSR. Other video datasets were considered but not utilized because they did not meet image
quality or transect criteria.
ESM Fig. S1: The bar plot shows the total cumulative duration of pre-spill video (1997-2003) and postspill video (2011) used in a Before-After-Control-Impact comparison of large sea fan health and condition
on mesophotic reefs in the northern Gulf of Mexico. Resources are United States Geological Survey
(USGS), Mississippi-Alabama Marine Ecosystem Study (MAMES; Brooks and Giammona 1990), and
the Natural Resource Damage Assessment (NRDA) field research conducted in 2011.
ESM Fig. S2: The bar plot shows the frequency of occurrence (in observations per minute) for large sea
fans (in dark gray) and small sea fans (in small gray) for each study site. Error bars are standard deviation.
The frequency of large sea fans is lower, but more consistent across sites.
ESM Fig. S3: The bar plot shows the frequency of occurrence (in observations per minute) of fishing
gear observations before the DWH oil spill (in light gray) and after the DWH oil spill (in dark gray) for
each study site. Error bars are standard deviation.
ESM Fig. S4: In-situ image of Hypnogorgia pendula on Roughtongue Reef at 61 meters depth in 2014. Lasers are 10 cm.
ESM Fig. S5: Close-up image of Hypnogorgia pendula polyps in-situ, image courtesy NOAA, Flower Garden Banks
National Marine Sanctuary.
ESM Fig. S6: On-deck image of Hypnogorgia pendula at Coral Trees Reef, depth of 89 meters, sample HC2-B0920-TN9-1154 collected in 2011.
ESM Fig. S7: SEM plate of Hypnogogia pendula sclerites. The upper half of the image shows spindles and rods from the
body wall, and the lower half shows the large spindles in the coenenchyme which are diagnostic of the species. Sclerites
are from sample HC2-B0920-T-N9-1154 subsample 3067.
ESM Fig. S8: In-situ image of Swiftia exserta on Yellowtail Reef at a depth of 58 meters in 2014. Lasers are 10 cm.
ESM Fig. S9: On-deck image of Swiftia exserta on Alabama Alps Reef at a depth of 70 meters in 2010. The image is
sample GU2988-A0806-TE202.
ESM Fig. S10: Close-up of Swiftia exserta polyps, courtesy NOAA, Flower Gardens Banks National Marine Sanctuary.
ESM Fig. S11: SEM plate of Swiftia exserta sclerites showing spindles and capstans from both the inner and outer
coenenchyme. The sclerites are from sample GU2988-A0806-TE202.
ESM Fig. S12: In-situ image of Thesea nivea on Roughtongue Reef at a depth of 63 meters in 2014. Lasers are 10 cm.
ESM Fig. S13: Close-up image of Thesea nivea polyps from Alabama Alps Reef at a depth near 80 meters in 2011.
ESM Fig. S14: On-deck image of Thesea nivea from Mountain Top Reef at a depth near 70 meters in 2011. The image
shows sample HC2-B0927-MTR51-1686.
ESM Fig. S15: SEM plate of Thesea nivea sclerites. The left side shows the curved rods from the operculum and simple
spindles from the inner coenenchyme, the right side shows the double cones and double heads from the outer
coenenchyme. The sclerites from sample HC2-B0927-MTR51-1686 subsample 8010, collected in 2011.
ESM Fig. S16: In-situ image of Thesea rubra courtesy of NOAA, Flower Garden Banks National Marine Sanctuary.
ESM Fig. S17: In-situ image of Thesea rubra on Coral Trees Reef at a depth of 78 meters in 2014. Lasers are 10 cm. A
portion of this colony was collected as sample WS5-P1-E0707-T-CTR-GX018-2025-0056A.
ESM Fig. S18: On-deck image of Thesea rubra from Coral Trees Reef at a depth of 78 meters in 2014. The image shows
sample WS5-P1-E0707-T-CTR-GX018-2025-0056A.
ESM Fig. S19: SEM plate of Thesea rubra sclerites. The left side shows the large grains from the outer coenenchyme, the
right side contains the spindles from the inner and outer coenenchyme, as well as the smaller grains from the outer
coenenchyme. The light micrograph inset shows red sclerites from the outer coenenchyme and white sclerites from the
inner coenenchyme. The sclerites are from sample WS5-P1-E0707-T-CTR-GX018-2025-0056A.
ESM Fig. S20: Four panel plate showing in-situ images from the yellow plexaurid group referred to as Placogorgia spp.. Lasers are 10 cm. A.)
Placogorgia spp. from Coral Trees Reef. B.) Placogorgia tenuis from Coral Trees Reef. C.) Center yellow colony identified as Paramuricea sp. from
Madison Swanson Reef. D.) Muriceides cf. M. hirta from Alabama Alps Reef.
ESM Fig. S21: Four panel plate of on-deck images of from the yellow plexaurid group referred to as Placogorgia spp.. All scale bars are 1cm. A.)
Sample from Alabama Alps identified as P. rudis. B.) Sample from Coral Trees identified as P. tenuis. C.) Sample from Alabama Alps identified as
Paramuricea sp. D.) Sample from Alabama Alps identified as Muriceides cf. M. hirta.
ESM Fig. S22: Scanning electron microscope plate of sclerites from the yellow plexaurid group referred to as Placogorgia spp.. Scale bars are 100µm.
A.) Thorn-scales, cortical spindles, and rods from the operculum indicative of P. rudis. B.) Thorn-scale, cortical spindle, and crutch shaped rods from the
operculum indicative of P. tenuis. C.) Thorn-scales and cortical spindles indicative of Paramuricea sp. D.) Thorn-spindles and three-arm radiates
indicative of Muriceides cf. M. hirta.