Wetenschap - 13 januari 2011

Corals in the nursery

Wageningen wants to play a part in the coral scene. Its first attempts are promising. The Dutch even has a first: an inland coral breeding nursery.

Biologist Ronald Osinga carefully attaches pieces of corals onto little plastic stands.
It is the first Friday morning in the new year. His new coral experiment is about to begin. More than a month ago, the little creatures were still living in the ocean facing the coast of CancĂșn in Mexico. They were flown into the Netherlands as hand luggage just before Christmas. Completely legal, by the way, stresses Osinga. They therefore have the necessary permits. And a nice story as well. Last month, Wageningen was at the centre of global coral research for an entire week, when Osinga played host to about three hundred congress participants. He used this opportunity to fly in corals from Mexico. Wrapped in wet tissue paper and placed inside plastic bags. This, explains Osinga, is called dry transport. 'It's lighter than in water and the corals are allowed into the cabin, which makes transport cheaper as well.' With the little ones being taken care of by scientists, their survival rate is much higher. 'We would rather not use couriers. That often goes wrong. A delay of just one day and the creatures die. Now we got them all within twenty hours from Mexico to Wageningen.'
Climate change
Osinga will examine how his Porites porites react to changed environmental conditions, these being in this case water acidity and availability of nutrients. In addition, changing light intensity and speed of water flow will also be simulated. 'These effects have individually been studied extensively', informs Osinga. 'What's new is the combination of variables which we will investigate into. We are interested in the interaction among these.' In short, Osinga wants to know how his corals react to climate change and how these animals grow in a different environment. This study is part of a big European project (www.FORCE-project.eu) where Alterra and Imares are participants.
Breeding corals; saving reefs
Some forty kilometres to the west, in an industrial area in Utrecht, Osinga's colleague Tim Wijgerde enters into a different kind of adventure. Wijgerde started early this year one of the world's first commercial coral breeding plants on land. It is in fact a feasibility study into breeding corals for the aquarium trade, Wijgerde explains. Corals in aquariums come mostly from nature at present, at the expense of tropical coral reefs. Worldwide, it is estimated that one to two million aquarium owners spend a small fortune of 300 million euros per year on corals. 'The demand for corals for aquariums will continue', says Wijgerde. 'You can't change that much, but we can make the sector more sustainable. By breeding coral to cater to demand, the natural coral reefs can be spared.'
Filter spares plankton
Coral breeding appears feasible, thanks to the development of a new water filtering method which leaves the plankton intact. Wijgerde: 'Corals depend a lot on plankton and light, but traditional filter systems kill the plankton. The new filter system, developed by the company EcoDeco, does not cause this problem. As such, coral breeding is within reach.' Under a programme for innovative ideas to protect biodiversity, the then Ministry of Agriculture, Nature and Food Quality (LNV) awarded 350,000 euros last summer to research into coral breeding. Wageningen UR and EcoDeco are working together in this project, under Wijgerde's lead.
Pioneers
Wijgerde and Osinga are the pioneers of a new shoot of the Wageningen research tree: tropical marine ecology. Both belong to the chair group Aquaculture and Fisheries of Professor Johan Verreth. 'Tropical marine ecology, which includes coral research, is a recent extension of our chair group', says Verreth. 'It fits well into the strategy of our group and that of the university. The addition of Bonaire, Sint Eustatius and Saba to Dutch territory has made coral ecology relevant, as well as research into coral breeding.' Verreth wants to go all out. 'It's now just a small research area in Wageningen, but we are going to expand considerably in the years to come.' A nice side effect, says the professor, is the strong attraction marine research has on students. Coral research is sexy and adventurous.
A sustainable coral market
For Wijgerde's coral plant, the adventure lies in the economic feasibility of breeding. Wijgerde does not doubt his mission. 'Corals grow by about one percent a day under optimal conditions. Every two and a half months, the biomass doubles. The test facility will grow 2000 thumb-size corals to the size of a fist. In one year, 4000 marketable units would be attainable. But the goals extend further: within five years, Wijgerde hopes to harvest as many as 50,000 corals annually. 'That is one third of the European market. We hope that in ten years' time, the global market would have been made sustainable to a large extent.'
Sensitive to climate change
Osinga will know in six months' time how his corals from CancĂșn fare in the changed climate they are exposed to. That will mark the end of part one of the experiment. Moreover, it will be the end for the corals. 'We will turn up the temperature slowly and observe what happens.' In fact, Osinga already knows the answer. The corals will turn pale, literally. 'The corals will lose the algae which stores light. As such, they will lose their major motor. That will be a fairly sudden and quick process. Within a few days, everything will have turned white. That's the turning point which we are looking for.'
 
Network unites scientists
Coral research in the Netherlands is increasing. The time is ripe for a club to call its own. This network is known as Acroporanet, named after the most common coral family in the world. The launch of the new club will take place on 30 March in Naturalis museum. 'Acroporanet is set up for people in the Netherlands who are involved in tropical marine biology research to exchange knowledge', explains Ronald Osinga, one of its founders. The network consists of several tens of researchers from universities (Wageningen, Groningen, Nijmegen, Amsterdam) and institutions (Naturalis, Deltares, Imares, NIOZ). Besides knowledge exchange, one of its main aims is to jointly guide marine onderzoek in the Netherlands. Go to  www.acroporanet.nl.

 

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