CORAL REPRODUCTION RESEARCH

Flow through filtration system set up on top deck of the M/V Fling under a shade canopy. Natural seawater was pumped up from below, run thorugh the system, then drained back into the Gulf. Photo: Drinnen/FGBNMS

Principle Investigator:

Dan Hilton
M.Sc. Candidate, Marine Biology
University of Calgary
Alberta, Canada
dhilton@ucalgary.ca

Research Focus:

Environmental Controls of Coral Spawning Behavior

Summary:

Dan Hilton is a graduate student under Dr. Peter Vize at the University of Calgary. His work, like Peter's is focused on deciphering what cues trigger coral spawning. Likely candidates are calcium, potassium, cyclic nucleotides, and other internal signal molecules.

In August 2007 Dan collected samples of Montastraea cavernosa to study in the lab in an effort to narrow down the field of candidates. Montastraea cavernosa was selected because it has larger polyps than most of the sanctuary species and therefore more protein to work with in the lab.

Pieces of M. Franksi colonies in tanks on the boat. Photo: Drinnen/FGBNMS

In September 2007, Dan returned to the sanctuary to experiment with the influence of added calcium on pre-spawn corals. This time his study centered on Montastraea franksi and its more reliable spawning schedule. Pieces of M. franksi from six different colonies were actually removed from the reef and brought on board the M/V Fling, where they were placed in a flow through filtration system using natural seawater.

M. franksi samples placed in containers and subjected to different calcium treatments to see how calcium might influence spawning behavior. Photo: Drinnen/FGBNMS

On the evening that M. franksi was expected to spawn on the reef, Dan broke each of his samples into 4 smaller pieces and placed them into separate containers. He then applied three different treatments to six samples each in an effort to increase internal calcium levels of the corals. Observations were then made to see if the treated samples spawned any earlier or later than the control samples or their counterparts still on the reef. Initial data seemed to show no effects from increasing the calcium levels, but decreasing calcium levels will likely be tested in the future.

Broken pieces of M. franksi were placed back into the open filtraion system after experimental calcium treatments, then epoxied back together. Photo: Drinnen/FGBNMS

Following this calcium experiment, Dan rinsed each of the coral samples thoroughly then placed them back in the flow-through filtration system until he was sure they were healthy. He then epoxied each of the original pieces back together then returned them to their exact locations on the reef. A little more epoxy secured them back in their rightful places. Dan jokingly refers to these as his "frankencorals".

And, if you're wondering how those "Frankencorals" will fair...Dan actually experimented with this reconstruction technique in 2006. One year later, the only sign of reconstruction is a tiny hairline fracture in the colony.

To learn more about what Dan and other students at the University of Calgary are doing, you can visit the Vize Lab web page.

Other Coral Reproduction Studies at the Flower Garden Banks National Marine Sanctuary:

Peter Vize
Sarah Davies