Taking apart a coral head, step-by-step

Florent with a coral head to be broken up.
Image: Angus Livingston



CReefs field work isn't all diving, eating and enjoying tropical sunsets. Mostly it is hard work and long hours.
Today volunteers Zamaria Rocio, part of the ARMADA program*, and Florent Angly, a PhD student from San Diego State University, spent several hours taking apart a dead coral head, brought back yesterday, to examine its contents.
Their work is part of Dr Laetitia Plaisance's study of the number and type of crustaceans, molluscs and echinoderms on these reefs.
Dr Plaisance, a researcher from the Smithsonian Institution based in Washington, said her study was part of the global Census of Marine Life.
"My work is being done to develop a standardised technique for assessing the biodiversity of reef invertebrates," she said.
That means Laetitia and her assistants are recording all types of invertebrates they find, rather than just trying to discover new ones.

An organism found in a coral head.
Image: Angus Livingston


To help everyone understand what goes into finding these organisms, Ms Rocio and Mr Angly have set out a step-by-step guide to what their work entails.
  • Step one: Fill a bucket of water about two-thirds of the way up and make a mark of the water level.
  • Step two: Remove the coral head from its tank and photograph it.
  • Step three: Put it in the bucket and measure the increase in water level to determine the volume of the coral head. It may be necessary to break the head up a little bit to make sure it is submerged.
  • Step four: Record the information.
  • Step five: Prepare a series of small water containers to hold what's found in the coral.
  • Step six: Start breaking the coral into small pieces and begin looking for organisms living within the skeleton. In this case, Ms Rocio and Mr Angly look for crustaceans, molluscs and echinoderms over five mm in size.
  • Step seven: Use tweezers and plastic spoons to remove the organisms, while hammers and chisels are used to break the coral apart. Sometimes the tweezers are necessary to remove algae on the coral that is making it difficult to see what's underneath.
  • Step eight: When something is found, it is placed in one of the water containers to be examined later.
  • Step nine: When they're finished with a piece of coral, the researchers put it in another bucket of water to be examined by other scientists looking for other organisms.
  • Step ten: Once the coral has all been picked through, the animals that have been extracted are taken to the laboratory for Laetitia to look through and take tissue samples for DNA analysis and classify them into species.
After the process is complete Mr Angly and Ms Rocio return to the laboratory to help Laetitia classify and tag the organisms.
*The ARMADA program provides American teachers with the chance to do field work in locations around the world. Ms Rocio is one of 10 teachers selected this year to go away.