Consultancy and ecological survey for the Albion Waterside development

Carcinus Ltd were contracted to conduct a benthic marine ecology survey along the foreshore near Albion Waterside, Gravesend. This survey took the form of an Extended Phase I Habitat survey to characterise the intertidal communities, sediments, and habitats in the area. The survey was conducted to inform an Environmental Impact Assessment (EIA) for a proposed development in the area, to which Carcinus are providing support in the form of scoping support and delivery of an Ecological Impact Assessment (EcIA). In addition, our team of consultants undertook a thorough literature review to produce a technical note in support of planned biodiversity enhancements at the development site.

Intertidal Benthic Survey

Permissions for the survey were granted in the form of a Survey Exemption from the Marine Management Organisation (MMO) and a Temporary River Works Licence (TRWL) in the form of a Letter of Consent from the Port of London Authority (PLA). A detailed work plan and project-specific risk assessments were compiled prior to the survey and agreed by the client.

The thick intertidal mudflat present along this stretch of the Thames presented challenging conditions for survey operations. To safely access the site, a single experienced Carcinus ecologist along with a highly qualified pilot, surveyed the entire area of mudflat in a single day using a specially designed hovercraft. The methodology followed adhered to a standard methodology set out in the Joint Nature Conservation Committee’s Marine Monitoring Handbook.

The ecologist initially undertook a visual assessment to identify and record the main soft and if any, hard substrate areas. Within each distinct habitat, the substratum and dominant / characteristic species were identified using a rapid in-situ inspection to assess sediment type, geomorphological features and biological features (e.g. worm tubes / casts or burrows). Sedimentary characteristics were described to outline sediment type, water content, the presence and depth of anoxic layer(s) and any other relevant features. Positional data were recorded using a handheld GNSS logger to mark the positions of any notable features. Additionally, a series of 0.25 m² quadrats placed haphazardly along the mudflat and river wall and carefully investigated to give more detailed information on surface flora and fauna. Additionally, a series of 0.01 m² cylindrical push cores were taken and were subsequently analysed for both biodiversity and particle size distributions.

Following the survey and successful completion of laboratory and statistical analyses, a technical report was produced which detailed the results of the biological and physical analyses. This technical report was subsequently used as background evidence for the EcIA that our consultants drafted.

Ecological Impact Assessment

As part of this project, Carcinus consultants were also contracted to deliver a Marine Ecological Impact Assessment, which would be presented as a technical appendix in the development application’s Environmental Statement.

The drafting of an Environmental Statement is a key component of the EIA process, and allows readers (be they regulators, statutory consultees or the public), to understand the nature of a proposal and make a decision on the potential environmental impacts.

Carcinus provides a suite of aquatic environmental consultancy services for their clients. For this project, Carcinus’ experienced marine environmental consultants drafted Ecological Impact Assessment focussing on the potential impacts to marine ecological receptors, including:

• Intertidal benthic ecology;
• Marine mammals; and
• Fish

The planning application for this project, including the input provided by Carcinus, is currently awaiting approval from the planning authority.