Aerial surveys of the Greater Thames were carried out over a total of 58 days over eight winter seasons between 1988/89 - 2006/07. These consisted of three strip transect aerial surveys (1988/89, 1989/90) and 20 line transect aerial surveys (2001/02-2006/07) conducted by Joint Nature Conservation Committee, Wildfowl & Wetlands Trust and the Natural Environmental Research Institute, Denmark.
The first part of this report describes analyses of these data to determine the numbers of birds present for each species. The second part of this report assesses those numbers against the appropriate guideline thresholds, to determine whether the area, or part of it, might meet the site selection requirements under Stage 1 of the UK Site Selection Guidelines as a Special Protection Area (SPA) under the European Union Birds Directive.