Our approach

The specification for each survey and report was determined at a start-up meeting to define the requirements for each deliverable. An initial desk-based review was conducted to determine the need and scope of each survey.

Intertidal survey

An intertidal mapping survey and quantitative coring survey was completed in the vicinity of White’s Jetty, Bell’s Wharf and the New Ferry Terminal. Phase I surveying was conducted to map intertidal habitats at a broad scale, groundtruthing habitat mapping derived from aerial imagery. The methods used were based on consideration of best practice guidance. Biotopes/habitats were assigned in the field (which was refined once core samples from the Phase II survey were analysed). For the Phase II survey, quantitative intertidal core samples were taken.
Key considerations of an EIA include potential effects of underwater noise and vibration effects (mainly from piling) on fish and marine mammals

Subtidal benthic survey

Subtidal surveys were conducted to provide general site characterisation to inform the assessments and covered the requirement to sample for the tentacled lagoon worm (Alkmaria romijni) which can occur in the subtidal and intertidal zone and are classed as nationally scarce due to their vulnerability to habitat changes.

Grab surveys were used to characterise benthic habitats/species in the vicinity of the New Ferry Terminal and associated dredge pocket. Subtidal grab surveys involved deployment of a mini-Hamon grab sampler from a survey vessel.

Laboratory analysis of intertidal and subtidal samples

All biological samples were processed according to APEM’s in-house Standard Operating Procedures (SOPs) and in full compliance with North-east Atlantic Marine Biological Analytical Quality Control (NMBAQC) scheme guidance. Taxa were identified to the lowest practicable taxonomic level, usually species, using appropriate taxonomic literature.

Desk-based review

A desk-based review of Environment Agency water quality data from stations just upstream and downstream of the project site was conducted to inform the water quality assessment. In addition, a desk-based review of marine mammals was also completed.

Outcomes

• APEM were initially commissioned to prepare the marine ecology sections of the Scoping Report and to design the surveys. Following successful completion of these tasks, APEM were commissioned to undertake the surveys, prepare the survey reports and complete the marine ecology chapters of the PEIR and Environmental Statement as well as other required ecological assessments.
• Key considerations included potential effects of the infrastructure and any dredging on benthic species of conservation importance; underwater noise and vibration effects (mainly from piling) on fish and marine mammals; release of chemicals from bottom sediments if dredging was required (with use of the EA’s SeDiChem tool for the WFD assessment); loss of intertidal habitat and introduction and spread of invasive non-native species. Appropriate mitigation measures were proposed as required.
• All of the reports were submitted to EDP on time ready for review by the Planning Inspectorate (PINS). The project is still ongoing and APEM’s deliverables have been submitted as part of the DCO application with the project due to go to Examination later in 2022. We’re watching the progress of this project with interest!

We’re proud to support our clients with projects large and small, and our specialist teams work together to provide accurate, reliable results that our clients can trust. If you’re looking for advice about surveys or would like to find out more about our marine team, contact us here.