The impact of changes in sewage treatment on seaducks wintering in the Firth of Forth,Scotland

Changes in the numbers and distribution of seaducks wintering in the Firth of Forth off Edinburgh following the introduction of sewage treatment are described. Numbers of scaup and goldeneye were considerably reduced and feeding flocks were only recorded at outfalls where sewage continued to be discharged in large quantities.Although food items borne in the sewage were important in determining local distribution patterns, it was unclear whether these or abundant invertebrates were the most important factor attracting seaducks to this area.As a result of an environmentally desirable improvement scheme the United Kingdom has lost an internationally important concentration of wildfowl.