Sampling will give key to the spread of species around reefs


By Angus Livingston
Tuesday 2 June 2009
WHEN Dr Laetitia Plaisance leaves Ningaloo and goes home to Washington, her work will have only just begun.
Laetitia is employed by the University of California but is working at the Smithsonian Institution in Washington.
Her project is to develop a method of estimating the biodiversity of coral reefs that can be repeated at reefs around the world.
That means she collects dead coral heads of a specific size from a specific depth and then takes samples of everything found in them.
"I do the collecting and sub-sampling here," she said. "Then I do the sequencing and all the statistical analyses [in Washington]."
That DNA sequencing involves samples of every organism – small and large – found in each coral head.
Once the results are known and each species is identified, Laetitia can do some statistical work on the numbers to better understand how species are spread among reefs.
One of the key aspects to this approach is that reef health can be regularly monitored.
"What we wanted most was a method to compare reefs," Laetitia said.
"We can repeat that method from year to year and see if the diversity is changing or not."
Due to rough weather last year, the CReefs team was restricted in taking samples from as many areas as they would have liked.
This year the weather has been better and the collections have included several different spots.
Laetitia said the diversity was surprisingly good at this location, but she will be able to tell more after she returns home.