By Alyssa Reis and Patrick White
On May 19 2019
While here in Curaçao, we were instructed to collect coral samples during some of our dives for Josh, one of our TA’s. Josh is pursuing his PhD in genetics and epigenetics of coral reefs. He is collecting coral fragments from two different species, Colpophyllia natans and Montastraea cavernosa, at each of the dive sites that we have been visiting. Once we return to Carmabi Research Station, he takes each sample from seawater and transfers the samples into a vial of 96% ethanol. The purpose of the ethanol solution is to keep the DNA in the coral tissues from degrading. Josh keeps the coral samples separated by not only species and location but also by the depths that they were collected at. The purpose of him keeping track of the depths that the samples were obtained from, is to see if there is a population shift at 5 meters to 10 meters and below 10 meters to 15 meters. The reason Josh is interested in these different depths is because the temperatures of the sea water is different as well as the sunlight that reaches the coral which could result in an epigenetic variation in the coral DNA that could facilitate in their survival. After Josh obtains his data from Curaçao, he plans to compare it to data that was collected in Florida Keys. He also plans to collect samples from across the Caribbean.
I have always thought all corals would be soft and squishy. The pictures of them would portray corals as seemingly jelly like structures that would have you bounce off of them if you were to ever accidentally run into one. Of course, I have never touched a coral either, as this was strictly forbidden. “It will kill the coral” I would hear from people at aquariums or even fish stores. The combination of all those factors equals me never touching a coral for 21 years believing that corals were squishy and soft the whole time. This of course is not the case. Corals are hard, at least hard corals are hard, like REALLY hard.
I came across this discovery while getting coral samples in Curacao. I was in a dive group of four with one TA. I was given a knife, a rock, a test tube, and instructions to smack a small piece off. Josh, the TA, went first to demonstrate how to do it. Making it look very easy me and my dive buddy were next. This was when I first touched the coral which is basically just a slimy rock. All of my preconceptions on coral went out the window. My dive buddy and I had to really hit the corals with the knife reinforced with a rock smack to the back of the knife’s handle. In a coral colony the part that is alive is very thin, but the bulk of the coral’s mass is the calcium carbonate structure that the animal produces, which is as hard as a rock!
The authors of this blog are students enrolled in Tropical Marine Ecology and Conservation, field courses run in the Caribbean by the University of South Florida. In 2019 and 2021, the course went to the Carmabi research station in Curaçao and dived around the island over a 10-day period, for training and to carry out research projects. In 2018, the group went to Soufriere, Saint Lucia, and took part in various projects in partnership with the Soufriere Marine Management Association. In this blog, students will document their activities and how they relate to course material.