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.
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.