The Mersey Estuary was designated as a Special Protection Area (SPA) for birds in 1995, to protect important populations of waders and wildfowl. The SPA is underpinned by two Sites of Special Scientific Interest (SSSI) (New Ferry and Mersey Estuary) which are further subdivided into units.
Natural England have an obligation to carry out monitoring of the habitats that support the bird species for which the SPA is designated to ensure that the Conservation Objectives are being achieved. Natural England contracted NIRAS Consulting in 2016 to carry out surveys of the saltmarsh in units 7, 8, 9, 10 and 11 of the Mersey Estuary SSSI to inform a condition assessment of the habitats that support the SPA features.
In addition to carrying out surveys to capture data on the floral communities and to inform a condition assessment of the saltmarsh, information was also collected on the abundance and distribution of Canada geese on the marsh to inform an assessment of their impact on the suitability of the saltmarsh to support the SPA features.