Samenvatting

The present study investigated the abundance and distribution of protected seagrass associated species within the introduced Halophila stipulacea meadows on St. Eustatius. These species are the queen conch, Caribbean spiny lobster, slender seahorse, green turtle and several species of grouper (Epinephelus striatus, Mycteroperca interstitialis, Mycteroperca venenosa), snapper (Lutjanus cyanopterus, Lutjanus analis) and the rainbow parrotfish. These species are commercially and ecologically valuable through fisheries, tourism and their contribution to biodiversity which maintains important ecosystem services. The introduction of H. stipulacea altered the seagrass meadows as it has significantly shorter shoots compared to native seagrasses, potentially affecting these protected seagrass associated species as they benefit from high complexity e.g. shelter. Current nature management however is based on outdated research which describes the situation prior to the introduction of H. stipulacea and no monitoring efforts are being made to update this. Furthermore, no baseline knowledge regarding the effect of H. stipulacea on the protected seagrass associated species or even the location of meadows was known prior to this study, resulting in a knowledge gap. Effective nature management is hindered by this knowledge gap and the aim of this research is to take the first step in providing an indication of the abundance and distribution of protected seagrass associated species to help close it.