This report provides the results of a terrestrial invertebrate survey to inform Natural England’s proposal to enlarge the Mucking Flats and Marshes Site of Special Scientific Interest (SSSI), notified (in part) for its invertebrate interest. The survey was conducted on land that makes up the northern Tilbury Fort Marshes to the south of Tilbury Town and to the east of Tilbury Docks.
The survey targeted the Broad Assemblage Type (BAT) W22 ‘wetland’. Data was collected via pitfall trapping, sweep netting and suction sampling.
A total of 211 species was recorded from the sample sites including 22 with a nationally significant status. The Specific Assemblage Type (SAT) that is most prominent at the site is the M311 ‘saltmarsh and transitional brackish marsh’ with a total of eight species of fidelity recorded (where the threshold for favourable condition is nine).
The report found that of the four areas which were surveyed only sub-compartment TFM13 was of conservation value with respect to invertebrates. The interest in this area is a small zone on the southern part of the site where there is a small fragment of brackish marsh. Recommendations are made to investigate this area further in order to see if it can be expanded, enhanced or connected to other nearby fragments. It is noted that reducing grazing pressures, increasing connectivity or re-wetting of surrounding land are potential management strategies that could be considered.