PhD Topic - Impact of the invasive Pacific oyster (Crassostrea gigas) on marine biodiversity conservation and ecosystem services

The Pacific oyster (Crassostrea gigas) was initially introduced into European waters in the 1960’s to offset the decline of native oysters. It was imported based on the knowledge that European waters were too cold for spawning and distribution would be confined to aquaculture sites. However, rising sea temperatures caused an increase in the spawning frequency of C.gigas and wild settlement has occurred on intertidal areas outside aquaculture sites. Dense, impenetrable C.gigas reefs now colonise intertidal mudflats and rocky shores in continental Europe and the UK, which may now interfere with feeding of wading bird and wildfowl species that overwinter in these habitats.

Aims 1. Does the presence of wild C.gigas change the invertebrate species, diversity, composition and biomass on mudflats and rocky shores?

2. To what extent are coastal birds and wildfowl affected by wild C.gigas settlement?

3. Can wild settlement of C.gigas be managed effectively in open systems?

4. How does the presence and management of invasive species such as C.gigas impact ecosystem services? e.g. fisheries and tourism