Effects of invasive species

Invasive species such as the Pacific oyster can have far-reaching effects on invaded ecosystems, including modifying parasite-host interactions and disease risk. We combine field studies with experimental approaches to identify the complex effects of invaders on native coastal ecosystems such as the Wadden Sea.

Sampling on a bed of invasive Pacific oysters by Anouk Goedknegt during her PhD project. Photo: David Thieltges

Oyster project

Invasive species often pose a risk for native ecosystems as they can affect ecosystem functioning and services. In this project, we investigated the impact of one of the most prominent invader in the Wadden Sea, the Pacific oyster Crassostrea gigas, on native predator-prey and pathogen-host interactions. We found that oysters have complex effects on parasite-host interactions, for exampling by co-introducing parasites such as the parasitic copepod Mytilicola orientalis which now also infects native mussels with detrimental effects. For more information, see PhD thesis by Anouk Goedknegt produced in the course of the project Effects of invasive species on native predator-prey and pathogen-host webs which was funded by NWO-ZKO/BMBF.

The Invasive parasitic <I>copepod Mytilicola</I> orientalis has been co-introduced with Pacific oysters and now also infects native blue mussels (<I>Mytilus edulis</I>). Photo: Marco Faase

Ongoing studies

We are continuing our research on the effects of invasive species on invaded coastal ecosystems such as the Wadden Sea together with colleagues from the Wadden Sea Station of the Alfred Wegener Institute on Sylt in northern Germany. In addition to further identifying the complex impacts of the Pacific oyster invasion, we also study the effects of invasive mud crabs (Hemigrapsus sp.) on native shore crabs (Carcinus maenas) and the Wadden Sea food web.