Abstract
Strategic environmental impact surveys in the early part of the 21st century accurately quantified aggregations of red-throated divers Gavia stellata in marine areas around England for the first time. Simultaneously, these areas were then proposed for both Marine Protected Areas (MPAs) of international importance (sensu EU Birds Directive) for the species. Prior to or simultaneous with these proposals, several offshore wind farm (OWF) developments were proposed, consented and built within the MPAs. Providing scientific advice on development within these MPAs has often proven challenging, as initially the evidence base was restricted to measured effects at relatively few OWFs. Here we summarise the evolution of survey and analysis methods that have helped shape our current understanding of red-throated diver behavioural responses to OWFs and make some recommendations to address remaining evidence gaps.