L (Lara) Jansen

MUMACO: Mussels as mangrove facilitators for Coastal Defense 

The coast of Demak, Java, Indonesia, is 4.5km of land has been lost to sea in the last 25 years. Local villages are constantly at risk of flooding. In a joint effort TU Delft, Universitas Diponegoro and WUR are working on a solution that enables not only coastal defense, but also provides a viable business case for local fishermen and an opportunity for ecosystem restoration. Vertical poles reduce wave energy, promoting sediment accumulation and creating habitat that is suitable for mangrove recruitment, a natural coastal defense. Simultaneously, the poles are used for cultivation of native mussels, providing income for local fishermen and empowering locals to maintain the constructions. The construction also functions as an artificial reef that attracts many animals, thereby contributing to a balanced ecosystem and improved ecosystem services. In this way, Mussels function as Mangrove facilitators for Coastal MUMACO.

The aim of my PhD thesis is to assess the effects that mussel-covered poles have on the local ecosystem. Pelagic, benthic and epifaunal communities will be monitored throughout the duration of the project to understand if and how local biodiversity is increasing in response to the mussel-covered poles, and if additional fisheries can be enabled in a sustainable way. To this end, morphological identifications of animals are supplemented with a genomics approach using state-of-the-art sequencers. Stable isotope and stomach content analyses will provide insights in possible food web changes. In combination with size-frequency distributions and monitoring primary production, this will indicate whether or not the ecological carrying capacity of the ecosystem is enhanced.

If proven to be succesful, we hope that the principle in MUMACO can be translated to other regions facing similar problems.