Common Scoter (Melanitta nigra) Infaunal Data Collected During Academic Research Projects dataset https://portal.medin.org.uk/portal/start.php?tpc=007_NRW_DS111793 Carmarthen Bay, an extensive, shallow embayment off the south coast of Wales, UK, encompasses a wide range of rich and diverse coastal and marine habitats. Carmarthen Bay is an internationally important wintering ground for the Common Scoter duck (Melanitta nigra) and is widely regarded as the most important such site in the UK causing the site to be proposed as a Special Protection Area (pSPA) under the EC Birds Directive. The Common Scoter is strongly migratory and often travels considerable distances over land making brief stop-overs on inland waters. Its diet consists predominantly of molluscs, especially during the winter, although it occasionally takes other aquatic invertebrates such as crustaceans (e.g. barnacles and shrimps), worms, echinoderms, isopods, amphipods and insects (e.g. midges and caddis flies) as well as small fish and fish eggs. The large concentrations of this species that occur during the moulting period and in winter are highly vulnerable to oil spills, human disturbance and the degradation of food resources as a result of oil exploration. The need for a comprehensive baseline survey of the macro fauna communities of Carmarthen Bay became a priority for government agencies such as the Countryside Council for Wales in the wake of the Sea Empress oil spill February 1996. The long-term presence of certain infaunal species and the stability of the areas populations of the species may be a factor in the importance of the Carmarthen Bay is an internationally important overwintering site for the common scoter. This dataset consists of an extensive series of surveys of the macrofauna around Carmarthen Bay and was collated to identify environmental and / or biotic conditions relating to areas where scoter number were high or low. The majority of this dataset is data generated as part of a Countryside Council for Wales (CCW) funded PhD for the University of Wales Swansea known as \Carmarthen Bay infauna scoter project\". It also includes data related to a University of Wales Swansea MSc Environmental biology dissertation entitled 'Common Scoter Melanitta nigra in their wintering habitats; an investigation into the factors influencing their finer scale distribution'. Data was collected by students with CCW involvement or supervision." 20041231