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August 11-14, 2009
R/V Manta


Each year the coral spawning event is greatly anticipated by both researchers and recreational divers. This year, August spawning was moderate, but occurred somewhat as predicted. A second spawn was also predicted to occur in September.

As usual, the sanctuary research team was on hand to make observations. They were joined by National Ocean Service (NOS) Ocean Media Center videographers, as well as University of Texas (UT) and Texas A&M Galveston (TAMUG) researchers. The researchers were specifically studying the uptake of zooxanthellae by larval corals and plankton variation comparisons between spawning and non-spawning periods.

The remains of a recruitment rack, part of a permitted experiment that was destroyed by hurricanes, were also consolidated for future recovery. 

The underside of a manta ray swimming to the left.  Most of the belly area is white, with two dark blotches located near the base of the gill slits.
One of the manta rays sighted by researchers at East Flower Garden Bank. Photo: Schmahl/FGBNMS


*Chuck Currie, Captain
*Ward "Rocky" Watson, Mate
*Jack Gray, Deckhand

Research Team:
*John Brooks, NOS Ocean Media Center
*Sarah Davies, University of Texas - Researcher
*Ryan Eckert, FGBNMS Research Intern - Deck/Dive Support
*John Embesi, FGBNMS Research Specialist - Dive Support
*LTJG Tracy Hamburger, FGBNMS Operations Officer - Dive Support
*Emma Hickerson, FGBNMS Research Coordinator - Principle Investigator, Dive Support
*Paul Hillman, NOS Ocean Media Center
*Courtney Horne, Texas A&M University Galveston - Researcher
*Eli Meyer, University of Texas - Researcher
*Marissa Nuttall, FGBNMS Research Assistant - Dive Support
*G.P. Schmahl, Sanctuary Superintendent - Dive Support

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East Bank Activities

The R/V MANTA was loaded and left the dock on Pelican Island in Galveston at around midnight on August 10, 2009.  We arrived at East Flower Garden Bank (EFGB), buoy #5, on August 11th at about 6:30 a.m. 

Four divers swimming above coral reef and sand flat to reset a piece of equipment. Two divers are carrying the water quality instrument, while two more divers follow with camera equipment.
John Brooks and Paul Hillman film John Embesi and Emma Hickerson as they swim the Seabird water qualty instrument back to the instrument rack at East Flower Garden Bank. Photo: Schmahl/FGBNMS

During the first morning dives we retrieved, downloaded, and redeployed the Seabird water quality instrument and acoustic receiver.

A white, tube-shaped instrument mounted vertically to a cross-shaped bracket attached to a metal rack partially buried in the sand.  Blue water and coral colonies are visible in the background.
Seabird water quality instrument mounted on a rack in the sand at East Flower Garden Bank. The instrument rack has been partially buried by shifting sand as a result of Hurricanes Rita (2005) and Ike (2008). Photo: Schmahl/FGBNMS

The Seabird collects temperature and salinity measurements, while the acoustic receiver tracks animals, such as mantas, that have been tagged with acoustic transmitters. 

A diver floating to the right of a line hanging down from a submerged buoy.  Attached to the line next to the diver is an oblong black canister.
Marissa Nuttall makes some notes on her wrist-mounted slate after attaching the acoustic receiver to the receiver mooring at East Flower Garden Bank. Photo: Schmahl/FGBNMS

Mantas were the main attraction for the morning, and remained so for the duration of the dives at East Bank. At least six individuals were documented over the course of the week.

The underside of a manta ray swimming to the left.  Belly markings show two large black blotches, some smaller black spots, and wide black margins along the fins.The underside of a manta ray swimming toward the right.  The belly markings include wide, black margins from the middle to the end of the fins and two dark blotches near the base of the gill slits.
Two of the manta rays sighted at East Flower Garden Bank. Photos: Schmahl/FGBNMS

Two of them were re-sightings, but four of them were new animals for our manta catalog.

The underside of a manta ray swimming to the right. Belly markings show several grayish-black blotches, some smaller black spots, and pale gray margins along the fins.
One of the manta rays sighted at East Flower Garden Bank. Photo: Schmahl/FGBNMS

We also worked with Sarah Davies to roll up what was left of her recruitment rack. Sarah had set up the rack in an open sand patch to look at coral recruitment. Unfortunately nature had other plans for the sand patch--the 2008 hurricane season did some major rearranging! 

Three divers kneeling in a sand flat, rolling up metal pipes in a section of chain link fence.
Marissa Nuttall, Sarah Davies, and Emma Hickerson roll metal pipes in chain link fence to bundle rack debris for future recovery. Photo: Schmahl/FGBNMS

Visibility was great at EFGB, about 100 feet (31m), and temperature was 84F (29C). There was no current.

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2009 Spawning Observations

Corals at the Flower Garden Banks usually spawn 7–10 days after the August full moon, but sometimes they also spawn 7-10 days after the September full moon.  If there are two full moons in August, we are also likely to see two spawning events that year.

This year’s coral spawning prediction was a little difficult due to the fact that the full moon was August 6th at 0:55 GMT (Greenwich Mean Time), which was August 5th at 7:55pm our time (Central Daylight Time or CDT).  Since this was relatively close to midnight, the question was whether to count the 5th or the 6th as the first night after the full moon. For planning purposes, we chose the earlier of the two dates. As it turned out, the corals spawned based on August 6th being the first night after the full moon. 

If that’s not confusing enough, the full moon fell quite early in the month, so we thought there would be a good chance that the corals would spawn again in September. We gave it a 50/50 chance this year. 

In general, the spawning event in August was not as prolific as we’ve seen in the past, but still well worth the trip.  The corals spawned at the predicted days and times. This included the star corals Montastraea cavernosa, Orbicella (Montastraea) franksi, Orbicella (Montastraea) faveolata, Stephanocoenia intersepta, and the brain coral, Pseudodiploria strigosa

Dome-shaped colony of star coral just before spawning begins.  The surface appears to be covered in tiny yellow balls.

A dome-shaped colony of star coral as it begins to spawn.  Small, white, bb-shaped egg packets are beginning to release from the colony and float in the water above.

A dome-shaped colony of coral continues to spawn.  More small, white, bb-shaped egg packets escape from the surface of the colony and float upward.

A dome-shaped colony of coral in full spawning mode.  Small, white, bb-shaped egg packets fill the water around the colony.

Sequence of Orbicella (Montastraea) faveolata spawning. Photo: Schmahl/FGBNMS

However, we didn’t see other spawning species that we typically expect, such as brittle stars (Ophioderma squamisissimum and O. rubicundum) and Christmas tree worms (Spirobranchus giganteus). Neither did we see the mass spawning of barrel sponges (Xestospongia muta).

The M/V Fling was also in the sanctuary with a boat load of recreational divers and reported seeing Christmas tree worms spawning the night before we arrived. Quite a few of their divers also came over for a tour of the R/V Manta.

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West Bank Activities

On August 13th, we headed over to West Flower Garden Bank (WFGB) for the day, to maintain the Seabird water quality instrument and acoustic receiver there.  The rack to which the Seabird instrument is attached was quite buried. We’ll have to dig that out before too long, but settled for removing just enough sand to allow access to the Seabird instrument itself.

Two divers dig sand out from around the base of a water quality instrument mounted to a rack on the sea floor.
John Embesi and Emma Hickerson digging out the Seabird instrument at West Flower Garden Bank. Photo: Schmahl/FGBNMS

After retrieving the Seabird, we also made some general observations. Unfortunately, it seems that the one and only WFGB elkhorn coral (Acropora palmata) is succumbing to a disease.

An elkhorn coral colony between a bright orange sponge on the left and a barrel sponge on the right.  The colony is split diagonally from top left to bottom right by a green line.  To the right of the line is greenish growth.  To the left of the line is healthy coral.
The only elkhorn coral colony (Acropora palmata) at West Flower Garden Bank is dying from some type of coral disease. Algae is taking over in places where the coral has already died. Photo: Schmahl/FGBNMS

While Marissa and Emma were redeploying the Seabird instrument later that day, a very curious black grouper came and sat at the tip of Emma’s fins to watch our progess. He stayed there long enough for Emma to turn around and get face to face. 

A scuba diver lying on an open sand patch facing to the right.  Facing the diver and also lying in the sand patch is a large fish.
A black grouper (Mycteroperca bonaci) eyeing Emma. Photo: Schmahl/FGBNMS

After attaching the instrument, Emma and Marissa swam the sand flat to make some observations.  There were at least five large queen conch (Strombus gigas) in the flat, and a 7-foot long male nurse shark was relaxing on top of on the large Siderastrea colonies on the north side of the flat.  The Xestospongia sponges that were infected with disease last summer, appear to be recovering. 

Interestingly, on this bank, we had a thermocline at about 65ft, where the water temperature was 84F above and 80F below.  We were also concerned at the lack of fish on the first couple of dives. 

After conducting our work at West Bank, we returned to East Bank to continue our spawning observations and research.

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2009 Spawning Summary

Following is the official report submitted to NOAA's Coral-List:

August 11, 2009
2125-2140 Montastraea cavernosa, 2 male colonies
2125-2140 Montastraea cavernosa, 1 female colony
2150-2155 Montastraea cavernosa, 2 colonies
2205 Orbicella (Montastraea) franksi, 1 colony

August 12, 2009
2133-2218 Orbicella (Montastraea) franksi, 34 colonies
2149 Pseudodiploria strigosa, 1 colony

August 13, 2009
2110-2135 Montastraea cavernosa, 8 male colonies
+2125-2210+ Orbicella (Montastraea) franksi, 59 colonies
+2125-2205 Pseudodiploria strigosa, 31 colonies
2250 Pseudodiploria strigosa, 1 colony
2240 Stephanocoenia intersepta, 1 male colony
2245-2330+ Orbicella (Montastraea) faveolata, 20 colonies

Other reported spawning observations:

August 10, 2009
2125-2140 Christmas tree worms (Spirobranchus giganteus)

August 11, 2009
~0930 Barrel sponge (Xestospongia muta)
2125-2140 Christmas tree worms, 2 male individuals

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Stetson Bank

On August 14th we spent our time at Stetson Bank, retrieving, downloading, and redeploying the Seabird water quality instrument and acoustic receiver. 

G.P and Emma also came across two very large, newly molted spiny lobster casings, several sharks, and two flying gurnards – the first record of these in the sanctuary! 

2009 September Spawning

The FGBNMS Research Team was unable to go back to the sanctuary during the predicted September spawning dates, but the M/V Fling did. Recreational divers on board the Fling reported that the spawn did indeed occur, and in quantities similar to the August spawn.

2010 Coral Spawning Predictions

Next year the August full moon falls on August 24th at 1705 GMT, which is 12:05 CDT locally, so we're going to count that as the first day after the full moon.  This means that the prediction for the spawn is August 30th (7 days after the full moon) to September 2 (10 days after the full moon). 

There is no guarantee that our predictions will be right.  The only thing we know for sure is that nature is driving this bus (or submarine). We are just along for the ride!

Dowload a copy of the 2009 Coral Spawning Cruise Report (692kb pdf).

For general information about the annual mass coral spawning event, please visit our Coral Spawning page.

For summaries and reports from other spawning seasons, please use the links below:

2010 Coral Spawning

2008 Coral Spawning

2007 Coral Spawning

2006 Coral Spawning

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Orange, branching gorgonian (soft coral) anchored in a bed of sponges and other sea life.
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