Salt marshes: crucial for coastal protection and birds

The salt marshes of the Wadden Sea - a UNESCO World Heritage Site - are among the last pristine ecosystems in North West Europe. Not only they are indispensable food grounds for millions of birds, but they also play an important role in coastal protection. Microbial ecologist Joana Falcão Salles, together with her research group and other UG ecologists (Chris Smit en Matty Berg), want to find out what the impact of climate change is on this sensitive area.

Lying on the border of land and sea, the salt marshes are extra sensitive to higher sea levels and longer periods of drought. Joana investigates the interaction between three "protagonists" in the area: the plant Sea Couch, the shrimp-like Orchestia gamarella and the microbes in the soil, the shrimps and the plants. "The three have been studied separately, but we are increasingly finding that the interaction between them is important." says Joana.

Recovery strategies

At the moment, there is a kind of optimum balance in the Wadden Sea. The plant does not want it to be too wet, the lobster not too dry. And thanks to the plant, the accretion and erosion of the salt marshes remain balanced and the ecosystem stays intact. But what if it gets wetter or drier? Joana: "The plants and lobsters will have to adapt to the new circumstances. We hypothesize that the microbes play a major role in this. We have known for a number of years that they can determine the evolution and adaption of their host. For example, it appears that in certain bird species the immune system can change within one generation. This is possible because it is not the host but the microbes that genetically adapt."

To investigate the influence of climate change, Joana wants to build a number of test situations in the laboratory. "In the test situations we look at how the plants react in varying combinations, i.e. with and without lobsters or microbes, to changing circumstances, such as prolonged drought or flooding." Joana: "With that knowledge, for example, recovery strategies can be developed for affected salt marshes.

The needs

However, because it involves an enormous number of organisms, an enormous number of DNA samples must be examined. We hope that with the support of alumni and others who feel involved with the Wadden area, we can raise the necessary 24,000 euros.”