There are various routes that marine invasive non-native species can arrive by and spread, and these are termed ‘pathways’. During stakeholder workshops held in the Severn Estuary area in 2023 and 2024, key pathways relevant to the Severn Estuary were identified and action plans were developed for each. For some of these pathways, there is already a wealth of information available on relevant actions and how to mitigate spread, which we have linked for users where appropriate. However, for other pathways, there is currently limited guidance on best practice mitigation. Our biosecurity action plans outline the actions that can be taken in the Severn Estuary to address the risks posed by marine invasive non-native species associated with these pathways.