The Pacific oyster (Magallana gigas), originally introduced to the UK for aquaculture, has established wild populations along much of the coastline. Native to the Pacific region, this resilient species thrives in intertidal and subtidal zones, attaching to rocks and artificial structures. While valued for its economic and culinary importance, its spread into wild habitats raises ecological concerns, as it can outcompete native species and alter local ecosystems by forming dense reefs.