Noise may cause disturbance to SPA species and needs to be considered to establish the baseline against which to compare dredging operations. Limited information was retrieved on current noise levels experienced by the waterfowl populations of the Thames Estuary, and no regular noise monitoring programmes were identified for this area. It has not, therefore, been possible to provide an in depth baseline description of noise levels along this stretch of the Thames. As a result, the baseline examines the likely background noise as well as the likely levels that would be generated by the maintenance dredging regime. This therefore represents the levels likely to be experienced by the waterfowl assemblages of the Thames Estuary and Marshes SPA, Benfleet and Southend Marshes SPA, and Holehaven SSSI.
Within the baseline it is considered that maintenance dredging is unlikely to be causing significant disturbance to waterfowl given the background levels of disturbance and the relative infrequency of dredging activities.