My research focuses on the ecological and evolutionary consequences of human activities for marine species and ecosystems. I have made significant contributions in the fields of invasion genetics, biogeography, biodiversity conservation and community ecology. A key example is the extensive use of the latest DNA sequencing techniques to improve our understanding of associations between intra-specific hybridization of divergent genotypes, successful colonization of non-native species, and rapid changes in species ranges. My career has developed across different institutions around the world including the Universities of California Davis, Cape Town, Queensland, and over the last eight years the work of my research group has been carried out at the National Oceanography Centre, University of Southampton (UK). Undertaking this research has meant collecting samples of marine organisms, seawater and sediment from different parts of the world using oceanographic vessels, and conducting intertidal and subtidal surveys.