Nature conservation and restoration in the Caribbean Netherlands

Wageningen Marine Research also conducts research relating to coast and climate in the Caribbean Netherlands. Coral researcher Erik Meesters elaborates on various ongoing projects.

Since 2010, the islands of Bonaire, Sint Eustatius and Saba have been special municipalities of the Netherlands. Accordingly, the Netherlands has a responsibility when it comes to nature conservation on and around the islands, says ecologist Erik Meesters of Wageningen Marine Research. He has been conducting research in this area since 1987. “During that time, I have seen drastic changes in the local nature”, he says. “Water pollution and overfishing are major problems, as is water turbidity due to the influx of sediment and nutrients from land. In more recent years, climate change has become an underlying driver of change.”

Richest ecosystems on earth
Efforts to limit the influence of all these pressures on nature require an in-depth understanding of the ecosystems, according to Meesters. “Much of the biodiversity is still unknown”, he emphasises. “The same goes for the interrelationships between living and non-living nature. For example, the combined role of temperature, light transmission and nutrients in the water.”

The ecosystems in the Caribbean Netherlands are among the richest on earth. Their base is formed by reef-forming corals. Their three-dimensional calcareous structures are home to all kinds of plants and animals and their complex food webs, from microscopic algae to colourful sea slugs and from tiny fish to the largest sharks. “While diving you can study the upper regions of coral reefs”, says Meesters. “For the deeper parts, we use underwater drones with remotely controlled cameras. We can also take samples using this equipment.”

Monitoring
The protection of this rich nature is a task of the Dutch Ministry of Agriculture, Nature and Food Quality. The government has therefore asked research institutes such as Wageningen Marine Research to map out these ecosystems – and create measures to protect them. “We mainly conduct research within 100 meters of the coastline”, says Meesters. “This is where you’ll find the ecosystems that are most important to the islanders for tourism and fishing. But we also study the Saba Bank, a deeper reef area that measures 60 by 40 kilometers, well off the coast of Saba. The Saba Bank is the largest protected nature reserve in the Netherlands.” 

We also use new environmental DNA techniques to investigate which animal and plant species occur at certain locations.

The research spans a wide range of efforts, as Meesters explains. Monitoring plays an important role. “For example, we investigate how coral reefs change over time”, he says, “as well as the water quality, transparency and the amount of chlorophyll in the water: a measure of phytoplankton growth that increases under conditions with higher nutrient concentrations. We also use new environmental DNA techniques to investigate which animal and plant species occur at certain locations.” 

Interventions
Based on these monitoring activities, Meesters and his colleagues advise the government: where are interventions needed, which interventions are they, and how can they best be carried out? “By counteracting erosion on land, you can prevent a lot of sediment from ending up in coastal waters, for example”, says Meesters. “On the island of Bonaire, EU money has been invested in a sewage treatment system. As a result, less sewage water ends up in the sea.”

Meesters and colleagues are also studying coral restoration. They do this in collaboration with students and local NGOs. For example, they set up biodegradable frameworks on which they attach coral fragments, as a basis for new reefs. They also investigate which genetic factors make some coral colonies more resilient to pressure factors than others. “Based on that, you can decide which populations you want to continue breeding with, and where.”

Resilience
Have these measures led to any concrete results yet? “I’m a bit ambivalent in that respect”, Meesters replies. “The islands are still incredibly beautiful and diverse. And we are already seeing some improvements, for example in the field of fisheries policy and wastewater treatment. Efforts are being made to combat overgrazing by donkeys and goats along the coast, thereby decreasing erosion. But at the same time, pressures have continued to increase, even in the past decade. In 2010, Bonaire had 12,000 inhabitants; now there are 22,000 and there’s a call for more tourism. This invariably increases the pressures on the environment, making it harder for corals to cope with other threats such as higher sea water temperatures due to climate change. Sometimes this makes me a little depressed.”

On the islands, nature conservation is increasingly high on the agenda. A number of good projects are already underway, especially with NGOs.

Meesters takes comfort in the fact that research by Wageningen Marine Research and other parties contributes to better protection of these ecosystems. “I am confident that this has positive effects”, he says firmly. “On the islands, nature conservation is increasingly high on the agenda. A number of good projects are already underway, especially with NGOs.” Last year a large joint project was launched, entitled ‘Resilience Restoration of Nature and Society in the Caribbean Netherlands’. It aims to improve nature and environmental management. Meesters: “So yes, a lot of good things are happening there too.”