North Thames Estuary & Marshes Area - Saltmarsh NVC Survey, 2023.
Abstract
This report details a phytosociological survey conducted by botanists from RSK Biocensus Ltd, mapping approximately 90 hectares of intertidal saltmarshes and adjacent halophytic vegetation along the northern shore of the River Thames, from the Thames Gateway Port to the Tilbury Cruise terminal. Using the National Vegetation Classification (NVC) method, the survey identifies and categorizes various saltmarsh communities, particularly highlighting the dominance of SM6 (Spartina anglica), SM11 (Aster tripolium var. discoideus), and SM14 (Halimione portulacoides) communities. These communities are found in different zones of the marsh, with Spartina anglica dominating the lower marsh, Aster tripolium var. discoideus in the landward areas, and Halimione portulacoides prevalent in the middle marsh. The survey also notes the presence of unusual species within these communities, such as Tripolium pannonicum var. flosculosus, Atriplex prostrata, Juncus gerardii, Juncus maritimus, and Elymus athericus. Additionally, the survey documents uncommon species like Artemisia maritima, Cochlearia anglica, and Lysimachia maritima behind the seawalls. Overall, the report emphasizes the ecological importance and distinctiveness of these saltmarshes within the inner and greater Thames estuary.