Intern Experience of Ashley Ford

Ashley Ford at Perry's Peak

PIMS Intern Report:

"Hungry, Hungry Diadema"

Ashley Ford, a sophomore at Auburn University, came to Lee Stocking Island in January for an 11-week research project as PIMS' Science Intern. Ashley developed an independent project focusing on Diadema antillarum, a long spined sea urchin, and its effect on algal communities. "I became interested in the relationship between Diadema and algae after listening to stories of recreational divers who, years ago, would move 5 or 6 of these urchins out of the way to capture lobsters," said Ashley.

The summer of 1983 was the beginning of a Caribbean-wide mass mortality of Diadema antillarum. Scientists soon discovered how valuable these urchins were to coral reefs when their die off caused more than ninety percent of the urchin population to vanish. Since the die off, there has been a shift from coral dominated reefs, to reefs mostly dominated by algae.

After discovering that very little information exists on these urchins, Ashley's hypothesis became clear; an increase in Diadema populations would result in a decrease in algal cover. Using plastic corrals to contain the Diadema on patch reefs dominated by algae, she selected 3 sites, taking weekly photos of the Diadema's impact on the algal growth. Her photos confirmed her hypothesis, showing a decline in the algal populations after just three weeks.

So what's the benefit of hungry Diadema on a coral reef? It's possible that, as Diadema populations increase and algal communities decrease, the coral head is cleaned making it an ideal location for coral recruits to settle and begin building a healthy coral reef.

<< Back