school of fish in background
Skip to page Header home about your sanctuary visiting your sanctuary education science management news and events protecting resources image library document library Get Involved advisory council partners NOAA logo - a circle with a stylized seabird in flight; background is dark blue above the bird and light blue below the bird.

blank spaceFind us on Facebook

     Follow @fgbnms on Twitter


Skip to Main Content
Science Home    Research    Monitoring    Habitat Characterization
Research Projects    Expeditions    Tools & Technology
Research Publications/Chronology


Every year, 7-10 days after the full moon in August, the reef-building corals of the Flower Garden Banks National Marine Sanctuary put on a fantastic spawning display. In ways that we still don't understand, each coral species times its gamete release for maximum benefit by avoiding the simultaneous spawning of other species. And, each year, sanctuary scientists and researchers from other facilities are there to observe this phenomenon in an effort to decipher even more pieces of the puzzle.

Cruise Highlights

The spiral gills of a Christmas tree worm protude above a spawning brain coral colony
A Christmas tree worm protruding from a spawning brain coral colony.
Photo: Schmahl/FGBNMS

Thanks to the nature gods, the corals spawned spectacularly on both the seventh and eighth night after the full moon (the eighth being the “bigger” of the two nights).  The star and brain corals released their gametes on cue.

A Christmas tree worm releasing spawn from its location atop a brain coral colony
A christmas tree worm spawns from its location atop a brain coral colony. Click on the image to see video footage.
Photo: Schmahl/FGBNMS
Video: Hickerson/FGBNMS



Brittle stars and christmas tree worms also spawned as expected, although there were a lot more Christmas tree worms “going off” than we’ve previously seen, and a lot fewer brittle stars.

A giant barrel sponge releasing spawn, which looks like snow, at West Flower Garden Bank
A giant barrel sponge spawning at West Flower Garden Bank.
Photo: Hickerson/FGBNMS



The big surprise was the spawning of the giant barrel sponges, Xestospongia muta.  We’ve had one report of this species spawning in the sanctuary and seen a photo or two, but never witnessed the event for ourselves. 

The spawn from a giant barrel sponge has settled onto the surrounding reef and looks like snow
The spawn from giant barrel sponges settled onto the reef like drifting snow.
Photo: Schmahl/FGBNMS



On the morning of the 6th night after the full moon, around 9:00 am, we were at the West Flower Garden Bank and the "snow storm" began. There was no current, so the eggs were forming a ring of white all around the sponges.


A third moment of discovery came when Doug Weaver and Emma Hickerson spotted a 5 foot long goliath grouper. We were able to obtain the first ever photographic evidence of this species in the sanctuary. This is an Endangered Species that warrants special protection and attention.

Download a copy of the full 2006 Spawning Cruise Report with photographs. (508kb pdf)

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

For summaries and reports from more recent spawning seasons, please use the links below.

2010 Coral Spawning

2009 Coral Spawning

2008 Coral Spawning

2007 Coral Spawning

top of page

weather report observations cool stuff get wet

Orange, branching gorgonian (soft coral) anchored in a bed of sponges and other sea life.
National Marine Sanctuary logo - a stylized whale tail above waves