EMEC Fall of Warness Grid-Connected Tidal Test Site

Site construction

The following potential environmental issues were identified for the construction of the Fall of Warness site:

• Modification to coastal processes (e.g. water movement and sedimentation patterns)
• Disturbance/modification to benthic habitats and communities due to cable laying in inshore waters.
• Disturbance (noise and physical presence) to wildlife including birds, cetaceans, turtles, pinnipeds and otters
• Pollution of water column from antifoulants, lubricants and hydraulic fluids.
• Ongoing minor disturbance to seabed communities in the immediate vicinity of the routes where the cable is laid on the seabed.
• Seabed disturbance/modification during foundation installation and during device installation/removal e.g. anchors etc.
• Disturbance (noise and physical presence) to local fish, seabird, seal, otter and cetaceans populations as a result of device installation.
• Loss of water current energy from the marine environment due to presence/operation of test devices may result in sedimentation and habitat and community modification and increased stratification in the water column.
• Foundations could affect seabed current flow and consequent sedimentary processes.
• Seabed scour around device foundations
• The effect of tidal turbines on seals and cetaceans is at present unknown as is the extent to which these populations pass through the waters of the Fall of Warness
• Wildlife entanglement/entrapment and collision with device blades e.g. diving bird populations, cetaceans (in particular the harbour porpoise), seals (in particular pups) and otters present in the area.
• Devices that break the sea surface may attract roosting birds and provide a seal haulout
• Electrical and electromagnetic effects – wildlife interactions

Of these environmental issues, those relating to seabed and coastal processes, water column contamination, and disturbance to wildlife were screened out due to the residual impact being classed as negligible. The only remaining environmental issue was:

• Disturbance/modification to benthic habitats and communities as a result of cable-laying in inshore waters.

Developers are not required to undertake a baseline seabed survey as this was carried out as part of the ES. They are however required to undertake a seabed survey post-decommissioning to assess the effect of the device upon the seabed. Other commitments are defined in the Guidance for Developers Document. [1].

Device testing

Potential residual impacts and their pathways associated with device testing are listed in EMEC’s Environmental Appraisal for the Fall of Warness site.

Mitigation Measures: 

Site construction:

The following section describes environmental mitigation measures undertaken during construction of the Fall of Warness site:

• Construction activities were planned to occur for 7 consecutive days in August, towards the end of the bird breeding season (cormorants) and before the start of the grey seal pupping season thus minimising any disturbance;
• Any evidence of wrecks encountered during cable laying were to be reported immediately to the County Archaeologist;
• Recognised marine standard materials held on vessel(s) and recognised marine working standards and regulations were applied;
• A Navigation Risk Assessment was undertaken and the site was marked on the appropriate charts providing the mariner with adequate information;
• The cable laying vessel complied with the International Regulations for Preventing Collisions at Sea (COLREGS) and displayed the appropriate lights and marks for a vessel restricted in her ability to manoeuvre;
• The works were promulgated by appropriate Notices to Mariners and  Navigational Warnings;
• Consideration was given to test berths being clear of the adverse weather ferry routes were possible (in the case of the surface piercing device), and away from the main transit route (in the case of the buoyant surface device);
• Appropriate marking, lighting and aids to navigation to be specified for all surface piercing devices;
• EMEC have implemented a wildlife monitoring programme to in an attempt to investigate the effect of device presence on marine wildlife; and
• EMEC has been involved with a number of other research institutions to identify the knowledge gaps and initiate research aimed at addressing these.

Device testing

Within EMEC’s Environmental Appraisal the following potential monitoring measures (where relevant) were listed for deployments at the Fall of Warness site:

• *Site-wide monitoring of wildlife abundance and density is currently delivered by EMEC for the developers. In the event that EMEC become unable to fund or conduct this monitoring, each developer must contribute accordingly to the continuation of this monitoring and data analysis;
• Focal studies on animal behaviour in the vicinity of devices and marine works;
• Monitor colonisation of selected devices and infrastructure. This may also form part of a marine non-native species (MNNS) management protocol or bio-fouling management;
• *Use of appropriate method(s) to detect collision or near miss, and monitor any other interaction between mega-fauna and the operating device;
• *Any use of underwater lighting at night to be gradual and alongside monitoring to determine any fish/bird attraction and collision risk for predators;
• In situ measurements of strength and range of Ei and B fields under different energy generation scenarios;
• Pursue passive and active monitoring on and around selected devices and infrastructure to inform knowledge base. This may also form part of a MNNS management protocol;
• Monitoring changes to hydrodynamic forces around particular devices would provide data that could inform impact modelling for later commercial-scale proposals. Lambkin et al (2008) may provide some useful information;
• *Acoustic monitoring of drilling and anchor/mooring installation noise at various distances and frequencies, particularly if novel methods are in use;
• *Establishing the acoustic signature of operating devices;
• *Reporting of observations from MMO records;
• *Depending on timing and duration of activities specific short term monitoring of, for example, seal haul outs may be required;
• *Device monitoring should be capable of alerting the developer to an entanglement event (e.g. use of load cells, underwater video); and
• Reporting of behavioural reactions through wildlife surveys (e.g. underwater video) and opportunistic observations.

(*) Monitoring measures which are a likely condition of a licence or consent (Note: although some of the above measures are described as not being required by the Regulator as a licence/consent condition, developers may choose to undertake research in these areas for their own purposes).