This report provides the results of an aquatic macroinvertebrate survey following on from previous surveys conducted in 2022 The survey results were also used to evaluate the conservation value of each compartment and the overall condition of the site. The survey area included eight sampling compartments between Tilbury Fort and the north of Mucking Marshes.
Invertebrate samples were collected in waterbodies using sweeps at different layers of the waterbody profile including floating vegetation, benthic layer and the submerged edge of the nearside bank. Waterbody characteristics were determined by sampling water within the surface 15cm of water. Abiotic parameters were recorded in the surface 10cm of water including pH, conductivity, total dissolved solids, temperature (all measured using a Hanna HI83303 Aquaculture Photometer). In addition to this, at each sample point, information was recorded on exposed and submerged bank profiles, channel width and depth, and levels of grazing, poaching, and shelving.
The survey recorded 27,687 specimens. Of these specimens 239 taxa of aquatic invertebrates were identified with 180 of these identified to species level. All compartments supported a number of Red Data Book (RDB) species, Notable species and local species. In total one species of RDB1 odonata, five species of RDB3 beetles, one RDB3 mollusc, 27 notable beetle species and three notable hemiptera were recorded.