Science “coral couple” Marijn van der Laan and Marit Pistor.
ST. EUSTATIUS--Coral reefs first appeared some 542 million years ago. Today, they occupy less than a quarter per cent of the ocean floor yet support 25 per cent of marine life. The Science Cafe, hosted by Caribbean Netherlands Science Institute (CNSI) once every month, learned how vital the role of these tiny colonisers is to the world’s marine ecosystems and to the shallow waters that flow around St. Eustatius and Saba.
For the last two years, successive teams of young scientists have been taking a close look at which corals feel at home on the two islands and which corals need a health check. Called Arossta, this project is sponsored by various Dutch institutes and local organisations such as St. Eustatius National Parks Foundation Stenapa, CNSI, the Saba Conservation Foundation and Golden Rock Dive Center.
Marijn van der Laan and Marit Pistor are the latest project gatekeepers to spot the type of local corals and count the many small fish that feed on the algae that inhabit this fascinating world.
Three days a week, these students of coastal marine biology from the Van Hall Larenstein University of Applied Sciences in Leeuwarden, dive down to 50 feet to satisfy their aquatic curiosity.
“However, we are very selective where we dive,” reported Marijn van der Laan. “Twelve months ago, our fellow students anchored three types of structures on the ocean floor near Crook’s Castle and Twin Sisters to promote the growth of coral colonies. These structures that we call reef balls, layered cakes and ‘natural’ rock reefs are now the focus of our scientific quest.”
Van der Laan explained that the “coral couple” are also selective about when they dive. “We normally dive late in the afternoon,” reports Marijn van der Laan. “We use UV [ultraviolet – Ed.] lighting that bounces off the corals in various colours that give away their location and pedigree. Too much sunlight and we lose contrast. Too little light and our video cameras could miss out on the fish count. And that count is important for knowing how healthy the local fish stocks are now and in the future.”
Marit Pistor insists that the Arossta Project is vital for predicting the future state of corals in the local region. “There are many factors that can inhibit the growth of corals, like erosion and overfishing,” she explains. “Last Tuesday’s stormy night was an eye-opener for the two of us. We dived to only a depth of 23 feet and could see absolutely nothing because of the contaminated island run-off.”
Dr. Teresa Leslie, Stenapa President, is adamant that overfishing is not an immediate problem. “Small fish love corals and big fish like to eat small fish. That is the way of the world and says more about psychology than biology. Unlike our ABC [Aruba, Bonaire and Curaçao – Ed.] cousins, our Statia fishing industry is – if anything – understaffed not over-fatigued.”
“But erosion on Statia is becoming an enormous problem. We are losing our geography, our history [Fort Oranje and other fortifications – Ed.] and our marine zoology. The Dutch are masters at water management and their expertise is urgently required on Statia to direct, drain, harvest and distribute rainwater.”
In the meantime, the two science divers announced some findings of their studies. “Layered cakes are more attractive places to cultivate corals. Runners up are natural rock structures then reef balls,” explained Pistor. “This may not make the world or perception wobble but for coral communities, it could prove life or death.”
However, the research is not expected to end there. Future plans involve creating a completely new artificial reef as well as starting pilot projects to study juvenile sea urchins and herbivorous fish species in local waters.
