Management Measures Tool for Marine Energy

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Accessing Management Measures that Support Deployment of Wave and Tidal Energy Devices

As the marine renewable energy (MRE) industry moves beyond deployment of individual wave and tidal energy devices towards arrays, certain risks of MRE devices on the marine environment are not well understood and have led to onerous monitoring requirements placed on device developers.

A workshop was held in May 2017 with researchers, regulators, and developers to create the basis for the tool shown below. In consultation with the research and regulatory communities, it was agreed that applying a set of robust management measures could act as safeguards for marine animals and habitats until available monitoring data allows for determining the level of risk from MRE devices. At that point, measures could be dialed back or removed, if warranted. More information on the workshop and input for the tool can be found here.

The Management Measures Tool for Marine Energy shows management (or mitigation) measures from past or current MRE projects as a reference to help manage potential risks from future projects and allow them to move forward in the face of uncertainty, or until a risk can be retired. Additional management measures are regularly added by the OES-Environmental team. In addition to the searchable tool below, the information can be downloaded here. The download file includes additional details not shown below, including comments from stakeholders on past experience, cost of management measures, and when a management measure is needed.

View the instructions document for more in-depth details and examples on how to use the Management Measure Tool for Marine Energy or check out this webinar for an overview and demonstration of the tool. 

Last updated January 2023

Displaying 101 - 200 of 339 management measures
Technology Project Phase Stressor Receptor Management Measure Advantages Challenges Project Documents
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Contamination

Potential for accidental or unplanned events which could lead to contamination of the marine environment.

Marine Mammals
Design feature

Physical Containment systems including bulk heads, closed circuit systems, pressure relief systems.

Reduces risk of contamination/pollution escaping from structure.

Foubister 2005, MeyGen 2012, Royal Haskoning and Sea Generation (Kyle Rhea) Ltd. 2013, Sustainable Energy Authority of Ireland (SEAI) 2011, The Marine Institute 2016, THETIS Energy 2009, EMEC Fall of Warness Grid-Connected Tidal Test Site, MeyGen Tidal Energy Project - Phase I, Kyle Rhea Tidal Stream Array Project, Atlantic Marine Energy Test Site (AMETS), Galway Bay Test Site, Torr Head Project
Wave, Tidal Operation & Maintenance Entanglement

Potential for marine animals to become entangled in device mooring lines and cables.

Marine Mammals
Cetaceans
Monitoring

Fishing debris detected during routine inspections of mooring lines and cables will be removed.

Remove/reduce risk of entanglement

Low cost measure, implemented as part of standard O&M procedures.

Regular monitoring will benefit system performance in addition to addressing environmental risks (e.g., early detection of damage or failures in the system).

Wave, Tidal Installation, Decommissioning Underwater noise

The potential effects from underwater noise generated during installation/construction (excluding piling).

Marine Mammals
Mitigation

Avoid/limit 'noisy works' within close proximity to sensitive sites (e.g., known seal haul outs during sensitive periods, defining appropriate clearance distances where necessary).

Could reduce potential effects on sensitive species during sensitive periods.

Could increase project construction timescales (e.g., if continuous drilling time is restricted or specific periods need to be avoided).

Orbital Marine Power 2014, Xodus AURORA 2010, Aquatera Ltd 2011, European Marine Energy Centre (EMEC) 2014, Davison and Mallows 2005, Xodus Group 2019, ScottishPower Renewables 2012, McGrath 2013, Aquatera 2017, The Marine Institute 2016, Federal Energy Regulatory Commission (FERC) 2020, DP Energy Ltd. 2017, HS1000 at EMEC, Wello Penguin at EMEC, EMEC Fall of Warness Grid-Connected Tidal Test Site, Strangford Lough - MCT (SeaGen), EMEC Billia Croo Grid-Connected Wave Test Site, Fair Head Tidal Array, Tocardo InToTidal at EMEC, Galway Bay Test Site, PacWave South Test Site, Fair Head Tidal Array
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Barrier to movement

Potential barrier to movement due to the physical presence of devices and associated moorings/support structures, cables and electrical equipment.

Reptiles
Monitoring

Monitoring of existing developments.

Reduces scientific uncertainty.

Can be complex and costly.

Wave, Tidal Operation & Maintenance Entanglement

Potential for marine animals to become entangled in lost fishing gear or other equipment trapped on infrastructure.

Reptiles
Sea turtles
Monitoring

Ensure standard notifications of loss of fishing gear in region notified to operators. Reporting of entanglement events.

Good practice for emergency preparedness.

Chances of lost fishing gear being reported is reportedly low.

Wave, Tidal Operation & Maintenance Changes in sediment dynamics

The potential wider or secondary effects (siltation changes or smothering) on protected or sensitive sub-littoral seabed due to scour or siltation around devices and associated moorings, support structures and export cables.

Benthic
Monitoring

Modelling to predict the interaction between changes in sediment dynamics and animals.

Reduces scientific uncertainty so appropriate management measures can be employed.

Limited management measures available to minimise interaction despite modelling to fully predict interaction.

Wave Operation & Maintenance Dissipation of wave energy

The potential wider or secondary effects on protected or sensitive sub-littoral seabed due to removal or alteration of energy flow arising from devices and moorings or support structures.

Benthic
Benthic invertebrates
Monitoring

Modelling to predict the interaction between wave energy and animals.

Reduces scientific uncertainty so appropriate management measures can be employed.

Limited management measures available to minimise interaction despite modelling to fully predict interaction.

Wave, Tidal Operation & Maintenance Habitat Creation

The introduction of infrastructure and artificial substrates will provide habitat and artificial refuges.

Benthic
Monitoring

Monitor near-field behaviours.

Reduces scientific uncertainty around collision risk, displacement, and other impacts.

Increased value/ fecundity of commercially important species.

Informs understanding of potential positivie impacts from colonization and use of project infrastructure.

This type of monitoring can be expensive and difficult to deliver in practice.

May require additional licensing (e.g. echosounders).

Foubister 2005, Magallanes Renovables 2020, Orbital Marine Power 2018, EMEC Fall of Warness Grid-Connected Tidal Test Site
Wave, Tidal Installation Barrier to movement

Potential barrier to movement due to the physical presence of devices and associated moorings/support structures, cables and electrical equipment.

Birds
Monitoring

Array installation carried out in phases.

Allows close monitoring to observe any unexpected effects.

GlaxoSmithKlineMontrose 2012, GSK Montrose Tidal Array
Tidal Operation & Maintenance Collision risk

Potential for collision with turbine blades.

Birds
Diving birds
Mitigation

Selective structural and blade coatings (e.g., colors to aide detection.

Unknown - it is possible that this will aid detection of subsea structures and help reduce risk.

Uncertainty around how animals use visual cues, could. Could result in 'attraction', increasing risk of collision.

Use of such measures may be limited to conform with IALA standards.

Xodus Group 2019, EMEC Billia Croo Grid-Connected Wave Test Site
Wave, Tidal Operation & Maintenance Entanglement

Potential for marine animals to become entangled in lost fishing gear or other equipment trapped on infrastructure.

Birds
Diving birds
Compliance

Ensure standard notifications of loss of fishing gear in region notified to operators. Reporting of entanglement events.

Good practice for emergency preparedness.

Help track effects/interaction with marine animals.

Chances of lost fishing gear being reported is reportedly low.

Wave, Tidal Installation Marine Non-Native Species (MNNS)

Potential for introduction of MNNS which can have an adverse impact on the native species at the site.

Birds
Design feature

Avoid the introduction of hard bottom substrate into a soft bottom habitat.

Ensures the efficient recovery of species native to the surrounding habitat.

May have technical implications.

Wave, Tidal Installation, Operation & Maintenance, Decommissioning Changes in sediment dynamics

Reduced visibility impacting prey detection and obstruction avoidance.

Fish
Monitoring

Modelling to predict the interaction between changes in sediment dynamics and animals.

Reduces scientific uncertainty so appropriate management measures can be employed.

Limited management measures available to minimise interaction despite modelling to fully predict interaction.

Wave, Tidal Operation & Maintenance Collision risk

Pontential risk of collision with device giving size and character of structure.

Fish
Design feature

Device components (e.g., transformer and power conditioning equipment) are designed internally.

Reduces potential for collision with external moving parts.

The Marine Institute 2016, Galway Bay Test Site
Wave, Tidal Operation & Maintenance EMF

Impacts of electromagnetic fields from landfall cables on sensitive species.

Fish
Demersal fish
Design feature

Bury cables where possible and viable.

Sustainable Energy Authority of Ireland (SEAI) 2011, Tidal Lagoon Power 2017, Federal Energy Regulatory Commission (FERC) 2020, Atlantic Marine Energy Test Site (AMETS), Swansea Tidal Lagoon (SBTL), PacWave South Test Site
Wave, Tidal Operation & Maintenance Entanglement

Potential for marine animals to become entangled in lost fishing gear or other equipment trapped on infrastructure.

Fish
Elasmobranch, large fish
Mitigation

Fisheries management: Agreement with fishermen not to fish near to the device, warning of the dangers of losing equipment.

Reduces potential for entanglement of fishing gear in mooring lines and thus potential for entanglement of marine animals.

Xodus Group 2019, EMEC Billia Croo Grid-Connected Wave Test Site
Tidal Operation & Maintenance Marine Non-Native Species (MNNS)

Potential for introduction of MNNS which can have an adverse impact on the native species at the site.

Fish
Mitigation, Design feature

Antifouling application on components such as the pile and rodos blades.

Helps prevent colonization of the device and structure, avoiding forming a stepping stone for non-native species.

Royal Haskoning and Sea Generation (Kyle Rhea) Ltd. 2013, Kyle Rhea Tidal Stream Array Project
Tidal Operation & Maintenance Changes in water flow

The potential wider or secondary effects on protected or sensitive sub-littoral seabed due to removal or alteration of energy flow arising from devices and moorings or support structures.

Habitat
Monitoring

Installation of ADCPs and turbulence sensors to better understand the baseline tidal flow conditions and hence the change in tidal flow due to presence of the device(s).

Reduce scientific uncertainty.

Tidal Energy Ltd 2008, Aquatera 2017, Ramsey Sound, Tocardo InToTidal at EMEC
Wave, Tidal Operation & Maintenance EMF

Impacts of electromagnetic fields from subsea cables on sensitive species.

Habitat
Benthic invertebrates
Design feature

Install cable protection, armor, rock placement, or other cable protection.

Reduce the level of EMF to surrounding water column and therefore any potential effects.

Reduces 'snagging risk' for vessels.

Creation of artificial habitat leading to greater fecundity in species.

May have an impact on surrounding benthic habitats and sensitive species.

Creation of artificial habitat may cause aggregation effect causing greater impact of EMF.

Uncertainty around the need for and efficacy of this measure.

Increased cost to project.

...Read more

May have an impact on surrounding benthic habitats and sensitive species.

Creation of artificial habitat may cause aggregation effect causing greater impact of EMF.

Uncertainty around the need for and efficacy of this measure.

Increased cost to project.

Reduced possibilities for decommissioning in future.

Direct disturbance/loss of benthic communities.

Read less
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Marine Non-Native Species (MNNS)

Potential for introduction of MNNS which can have an adverse impact on the native species at the site.

Habitat
Mitigation, Compliance

Adhere to appropriate measures when jettisoning ballast water.

Reduce/remove risk of transfer of non-native species.

Sustainable Energy Authority of Ireland (SEAI) 2011, Atlantic Marine Energy Test Site (AMETS)
Tidal Operation & Maintenance Changes in water flow

The potential wider or secondary effects on protected or sensitive sub-littoral seabed due to removal or alteration of energy flow arising from devices and moorings or support structures.

Marine Mammals
Design feature

Site selection.

Minimizes significance of interaction .

ScottishPower Renewables 2012, Ness of Duncansby Tidal Array
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Contamination

Potential for accidental or unplanned events which could lead to contamination of the marine environment.

Marine Mammals
Mitigation

Material selection - lubricants, coolants, hydraulic fluids etc. - selected with low ecotoxicity levels and biodegradable.

Reduces/removes risk of contamination/pollution from materials which may have escaped structure.

Use of lower toxicity materials may compromise performance, or impact other technical issues (e.g., fluid changes.)

Foubister 2005, MeyGen 2012, Xodus AURORA 2010, The Marine Institute 2016, THETIS Energy 2009, EMEC Fall of Warness Grid-Connected Tidal Test Site, MeyGen Tidal Energy Project - Phase I, Galway Bay Test Site, Torr Head Project
Wave, Tidal Operation & Maintenance Entanglement

Potential for marine animals to become entangled in lost fishing gear or other equipment trapped on infrastructure.

Marine Mammals
Cetaceans
Monitoring

Ensure standard notifications of loss of fishing gear in region notified to operators. Reporting of entanglement events.

Good practice for emergency preparedness.

Chances of lost fishing gear being reported is reportedly low.

Federal Energy Regulatory Commission (FERC) 2020, PacWave South Test Site
Wave, Tidal Operation & Maintenance Underwater noise

The potential effects from underwater noise generated by wave and tidal energy converters.

Marine Mammals
Monitoring

Measure noise generated by device(s) during operation to better understand the potential effects on sensitive species.

Measured noise levels can be correlated with threshold values of relevant species and baseline noise levels of the site to determine impact and need for adaptive management measures.

Can be complex and costly to undertake this type of monitoring in high energy environments.

Data and analysis have requirement for acoustic experts.

SIMEC Atlantis Energy Ltd 2011, Aquamarine Power Ltd 2011, Orbital Marine Power 2014, Minesto 2016, Xodus AURORA 2010, European Marine Energy Centre (EMEC) 2019, ScottishPower Renewables 2010, Davison and Mallows 2005, McGrath 2013, Royal Haskoning 2012, Orbital Marine Power 2018, Atlantis Resources Corporation at EMEC, Oyster 800 at EMEC, HS1000 at EMEC, EMEC Billia Croo Grid-Connected Wave Test Site, Sound of Islay Demonstration Tidal Array, Strangford Lough - MCT (SeaGen), Fair Head Tidal Array, Oyster 800 at EMEC
Wave, Tidal Installation, Decommissioning Changes in sediment dynamics

Reduced visibility impacting prey detection and obstruction avoidance.

Reptiles
Mitigation

Best practice methodologies to reduce resuspension of sediment during cable burial or device foundation/mooring installation.

Wave, Tidal Operation & Maintenance Entanglement

Potential for marine animals to become entangled in device mooring lines and cables.

Reptiles
Sea turtles
Design feature, Monitoring

Routine inspections of mooring lines. Implement features into existing control systems to detect entanglement events.

Remove/reduce risk of entanglement.

Likely to be required as part of the technical monitoring of the device and therefore not an additional cost.

Could be a costly measure for technology developers if not required as part of technical monitoring of device.

Tidal Operation & Maintenance Changes in water flow

The potential wider or secondary effects on protected or sensitive sub-littoral seabed due to removal or alteration of energy flow arising from devices and moorings or support structures.

Benthic
Benthic invertebrates
Monitoring

Pre and post installation monitoring of sensitive benthic communities, based on diver, drop down, static visual surveys (camera), or grab sampling.

Reduce scientific uncertainty.

Interpretation of data for statistical purposes may not have power to detect change generated by impact.

May require correlation with detailed Computational Fluid Dynamics studies and physical flow measurements.

SIMEC Atlantis Energy Ltd 2011, Tidal Energy Ltd 2008, Foubister 2005, European Marine Energy Centre (EMEC) 2011, ScottishPower Renewables 2010, Davison and Mallows 2005, Laminaria 2018, Royal Haskoning 2012, The Marine Institute 2016, Royal Haskoning 2019, Orbital Marine Power 2018, Aquamarine Power Ltd 2011, Atlantis Resources Corporation at EMEC, Ramsey Sound, EMEC Fall of Warness Grid-Connected Tidal Test Site, EMEC Shapinsay Sound Scale Tidal Test Site, Sound of Islay Demonstration Tidal Array, Strangford Lough - MCT (SeaGen), EMEC Billia Croo Grid-Connected Wave Test Site, North West Lewis Wave Array, Galway Bay Test Site, Oyster 800 at EMEC
Wave, Tidal Operation & Maintenance EMF

Impacts of electromagnetic fields from subsea cables on sensitive species.

Benthic
Benthic invertebrates
Design feature

Install cable protection, armor, rock placement, or other cable protection.

Reduce the level of EMF to surrounding water column and therefore any potential effects.

Reduces 'snagging risk' for vessels.

Creation of artificial habitat leading to greater fecundity in species.

May have an impact on surrounding benthic habitats and sensitive species.

Creation of artificial habitat may cause aggregation effect causing greater impact of EMF.

Increased cost to project.

Reduced possibilities for decommissioning.

...Read more

May have an impact on surrounding benthic habitats and sensitive species.

Creation of artificial habitat may cause aggregation effect causing greater impact of EMF.

Increased cost to project.

Reduced possibilities for decommissioning.

Direct disturbance/ loss of benthic communities.

Read less
MeyGen 2012, Foubister 2005, McGrath 2013, DP Energy Ltd. 2017, Federal Energy Regulatory Commission (FERC) 2020, MeyGen Tidal Energy Project - Phase I, EMEC Fall of Warness Grid-Connected Tidal Test Site, Fair Head Tidal Array, Fair Head Tidal Array, PacWave South Test Site
Wave, Tidal Installation, Decommissioning Habitat Loss

Direct loss of protected or sensitive sub-littoral seabed communities due to the presence of devices and associated moorings or support structures on the seabed.

Benthic
Benthic invertebrates, demersal fish
Design feature

Micrositing of offshore infrastructure to avoid sensitive habitats and minimise footprint.

Could reduce/remove effects on sensitive habitats.

Low cost measure at single device or small-scale array.

Foubister 2005, Royal Haskoning and Sea Generation (Kyle Rhea) Ltd. 2013, RSK Group 2012, South West of England Regional Development Agency (SWDRA) 2006, Magallanes Renovables 2020, ScottishPower Renewables 2012, Laminaria 2018, The Marine Institute 2016, THETIS Energy 2009, EMEC Fall of Warness Grid-Connected Tidal Test Site, Kyle Rhea Tidal Stream Array Project, Wave Hub, EMEC Billia Croo Grid-Connected Wave Test Site, Galway Bay Test Site, Torr Head Project
Wave, Tidal Installation Barrier to movement

Potential barrier to movement due to the physical presence of devices and associated moorings/support structures, cables and electrical equipment.

Birds
Design feature

Site selection to avoid sensitive routes/areas.

Minimizes risk of development acting as a barrier to movement by avoiding migratory routes or other important sites.

Argyll Tidal Limited 2013, OpenHydro and SSE Group 2013, ScottishPower Renewables 2012, Argyll Tidal Demonstrator Project, Brims Tidal Array, Ness of Duncansby Tidal Array
Tidal Operation & Maintenance Collision risk

Potential for collision with turbine blades.

Birds
Diving birds
Mitigation

Implement a 'soft start' approach during cut-in.

Could reduce risk by allowing animals time to move away from the turbine.

Low cost option, adopted for other activities (e.g., piling)

Unclear if this offers additional mitigation as many devices power up gradually anyway.

Wave, Tidal Operation & Maintenance Entanglement

Potential for marine animals to become entangled in device mooring lines and cables.

Birds
Diving birds
Monitoring, Design feature

Routine inspections of mooring lines. Implement features into existing control systems to detect entanglement events.

Remove/reduce risk of entanglement.

Likely to be required as part of the technical monitoring of the device and therefore not likely an additional cost.

Potential cost of measure for technology developers if not required as part of technical monitoring of the device.

Federal Energy Regulatory Commission (FERC) 2020, PacWave South Test Site
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Marine Non-Native Species (MNNS)

Potential for introduction of MNNS which can have an adverse impact on the native species at the site.

Birds
Monitoring

Monitoring and reporting of MNNS.

Reduce/removes risk of transfer of non-native species.

Tidal Operation & Maintenance Changes in water flow

Modifications to tidal flows affect prey distribution and abundance resulting in changes to foraging behavior.

Fish
Monitoring

Observational surveys (including remote sensing) of species (prey availability linked to benthic community).

Reduce scientific uncertainty.

Statistical power of studies can be low. Can be difficult to distinguish between natural variation and direct effects of energy removal from the system.

Wave, Tidal Installation, Operation & Maintenance, Decommissioning Contamination

Potential for accidental or unplanned events which could lead to contamination of the marine environment.

Fish
Design feature

Physical Ccontainment systems including bulk heads, closed circuit systems, pressure relief systems.

Reduces risk of contamination/pollution escaping from structure.

Foubister 2005, MeyGen 2012, DP Energy Ltd. 2013, Royal Haskoning and Sea Generation (Kyle Rhea) Ltd. 2013, Magallanes Renovables 2020, Sustainable Energy Authority of Ireland (SEAI) 2011, The Marine Institute 2016, THETIS Energy 2009, EMEC Fall of Warness Grid-Connected Tidal Test Site, MeyGen Tidal Energy Project - Phase I, West Islay Tidal Project Energy Park, Kyle Rhea Tidal Stream Array Project, Atlantic Marine Energy Test Site (AMETS), Galway Bay Test Site, Torr Head Project
Wave, Tidal Installation EMF

Impacts of electromagnetic fields from landfall cables on sensitive species.

Fish
Demersal fish
Design feature

Device components (e.g., transformer and power conditioning equipment) are designed internally.

Reduces field effects external to the device.

DP Energy Ltd. 2013, Aquatera Ltd 2011, West Islay Tidal Project Energy Park, Wello Penguin at EMEC
Wave, Tidal Operation & Maintenance Entanglement

Potential for marine animals to become entangled in device mooring lines and cables.

Fish
Elasmobranch, large fish
Design feature

Minimise the number of mooring lines.

Reduce risk of entanglement.

Could be a costly measure for technology developers.

Wave, Tidal Installation, Decommissioning Underwater noise

The potential effects from underwater noise generated during installation/ construction (excluding piling).

Fish
Mitigation

Avoid/limit 'noisy works' within close proximity to sensitive sites i.e. known seal haul outs during sensitive periods, defining appropriate clearance distances where necessary.

Could reduce potential effects on sensitive species during sensitive periods.

Could increase project construction timescales (e.g., if continuous drilling time is restricted or specific periods need to be avoided).

Aquatera Ltd 2011, Davison and Mallows 2005, ScottishPower Renewables 2012, McGrath 2013, Aquatera 2017, The Marine Institute 2016, Federal Energy Regulatory Commission (FERC) 2020, THETIS Energy 2009, Wello Penguin at EMEC, Strangford Lough - MCT (SeaGen), Fair Head Tidal Array, Tocardo InToTidal at EMEC, Galway Bay Test Site, PacWave South Test Site, Torr Head Project
Tidal Operation & Maintenance Changes in water flow

The potential wider or secondary effects on protected or sensitive sub-littoral seabed due to removal or alteration of energy flow arising from devices and moorings or support structures.

Habitat
Design feature

Design structures to minimise effect on turbulence structure.

Minimizes change in turbulence structure and hence potential interaction.

Can present financial, logistical, or design challenges to technology developer to alter design of device/moorings.

Aquamarine Power Ltd 2011, Davison and Mallows 2005, Tidal Energy Ltd 2008, Oyster 800 at EMEC, Strangford Lough - MCT (SeaGen), Ramsey Sound
Wave, Tidal Operation & Maintenance EMF

Impacts of electromagnetic fields from subsea cables on sensitive species.

Habitat
Benthic invertebrates
Design feature

Use of 3-phase cables instead of DC cables.

Reduce the level of EMF to surrounding water column and therefore any potential effects.

Potential commercial and technical feasibility issues.

Uncertainty around the need for and efficacy of this measure.

Wave, Tidal Installation, Operation & Maintenance, Decommissioning Marine Non-Native Species (MNNS)

Potential for introduction of MNNS which can have an adverse impact on the native species at the site.

Habitat
Mitigation

Source vessels locally.

Reduce/remove risk of transfer and settlement of non-native species.

Orbital Marine Power 2018
Tidal Operation & Maintenance Changes in water flow

Modifications to prey distribution and abundance (to include for other receptors) resulting in changes to foraging behaviour.

Marine Mammals
Design feature

Site selection.

Minimizes significance of interaction.

ScottishPower Renewables 2012, Ness of Duncansby Tidal Array
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Contamination

Potential for accidental or unplanned events which could lead to contamination of the marine environment.

Marine Mammals
Mitigation

Where rock placement is used, ensure clean rock is used.

Reduces/removes risk of contamination/pollution from materials

Wave, Tidal Operation & Maintenance Entanglement

Potential for marine animals to become entangled in device mooring lines and cables.

Marine Mammals
Cetaceans
Design feature, Monitoring

Routine inspections of mooring lines. Implement features into existing control systems to detect entanglement events.

Remove/reduce risk of entanglement.

Likely to be required as part of the technical monitoring of the device and therefore not an additional cost.

Could be a costly measure for technology developers if not required as part of technical monitoring of device.

Argyll Tidal Limited 2013, Federal Energy Regulatory Commission (FERC) 2020, Orbital Marine Power 2018, Argyll Tidal Demonstrator Project, PacWave South Test Site
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Underwater noise

The potential effects from underwater noise generated during installation/ construction (excluding piling).

Marine Mammals
Mitigation

Limit vessel speed.

Reduces potential effects.

Relatively low-cost measure.

SIMEC Atlantis Energy Ltd 2011, Atlantis Resources Corporation at EMEC
Wave, Tidal Installation, Decommissioning Changes in sediment dynamics

Sediment disturbance disrupting water clarity that results in smothering of fish spawning grounds.

Reptiles
Mitigation

Best practice methodologies to reduce resuspension of sediment during cable burial or device foundation/mooring installation.

Wave, Tidal Operation & Maintenance Entanglement

Potential for marine animals to become entangled in lost fishing gear or other equipment trapped on infrastructure.

Reptiles
Sea turtles
Mitigation

Fisheries management: Agreement with fishermen not to fish near to the device, warning of the dangers of losing equipment.

Reduces potential for entanglement of fishing gear in mooring lines and thus potential for entanglement of sea turtles.

Tidal Operation & Maintenance Changes in water flow

The potential wider or secondary effects on protected or sensitive sub-littoral seabed due to removal or alteration of energy flow arising from devices and moorings or support structures.

Benthic
Monitoring

Installation of ADCPs and turbulence sensors to better understand the baseline tidal flow conditions and hence the change in tidal flow due to presence of the device(s).

Reduce scientific uncertainty.

Tidal Energy Ltd 2008, Aquatera 2017, Ramsey Sound, Tocardo InToTidal at EMEC
Wave, Tidal Operation & Maintenance EMF

Impacts of electromagnetic fields from landfall cables on sensitive species.

Benthic
Benthic invertebrates
Design feature

Install cable protection or armour.

Foubister 2005, Federal Energy Regulatory Commission (FERC) 2020, EMEC Fall of Warness Grid-Connected Tidal Test Site, PacWave South Test Site
Wave, Tidal Installation, Decommissioning Habitat Loss

Direct loss of protected or sensitive sub-littoral seabed communities due to the presence of devices and associated moorings or support structures on the seabed.

Benthic
Benthic invertebrates, demersal fish
Design feature

Minimize footprint of anchors / foundations.

Could reduce effects on sensitive habitats.

May impact technical considerations, such as size of anchors/foundations that are safe and optimal for operation of device(s).

Aquamarine Power Ltd 2011, Aquatera Ltd 2011, Royal Haskoning and Sea Generation (Kyle Rhea) Ltd. 2013, RSK Group 2012, ScottishPower Renewables 2012, The Marine Institute 2016, Federal Energy Regulatory Commission (FERC) 2020, Oyster 800 at EMEC, Wello Penguin at EMEC, Kyle Rhea Tidal Stream Array Project, Galway Bay Test Site, PacWave South Test Site
Wave, Tidal Installation Barrier to movement

Potential barrier to movement due to the physical presence of devices and associated moorings/support structures, cables and electrical equipment.

Birds
Design feature

Array/ mooring configuration designed to avoid migratory routes or other important sites.

Minimises risk of development acting as a barrier to movement by avoiding migratory routes or other important sites.

May be inconsistent with optimal layout of the development for exploitation of the energy source.

Can be a costly measure when scaling up to larger arrays.

Aquamarine Power Ltd 2011, Oyster 800 at EMEC
Wave, Tidal Operation & Maintenance Collision risk

Pontential risk of collision with device giving size and character of structure

Fish
Design feature

Device components (e.g., transformer and power conditioning equipment) are designed internally.

Reduces potential for collision with external moving parts.

Aquatera Ltd 2011, The Marine Institute 2016, Wello Penguin at EMEC, Galway Bay Test Site
Wave, Tidal Operation & Maintenance Entanglement

Potential for marine animals to become entangled in lost fishing gear or other equipment trapped on infrastructure.

Birds
Diving birds
Mitigation

Fisheries management: Agreement with fishermen not to fish near to the device, warning of the dangers of losing equipment.

Reduces potential for entanglement of fishing gear in mooring lines and thus potential for entanglement of marine animals.

Xodus Group 2019, EMEC Billia Croo Grid-Connected Wave Test Site
Wave, Tidal Installation, Decommissioning Underwater noise

The potential effects from underwater noise generated during installation/ construction (excluding piling).

Birds
Seabirds
Mitigation

Avoid/limit 'noisy works' within close proximity to sensitive sites (e.g., known seal haul outs during sensitive periods) defining appropriate clearance distances where necessary.

Could reduce potential effects on sensitive species during sensitive periods.

Could increase project construction timescales and thus costs (e.g., if continuous drilling time is restricted or specific periods need to be avoided).

Aquatera Ltd 2011, Davison and Mallows 2005, ScottishPower Renewables 2012, McGrath 2013, Orbital Marine Power 2014, Aquatera 2017, Federal Energy Regulatory Commission (FERC) 2020, THETIS Energy 2009, Orbital Marine Power 2018, Wello Penguin at EMEC, Strangford Lough - MCT (SeaGen), Fair Head Tidal Array, Tocardo InToTidal at EMEC, PacWave South Test Site, Torr Head Project
Tidal Operation & Maintenance Changes in water flow

The potential wider or secondary effects on protected or sensitive sub-littoral seabed due to removal or alteration of energy flow arising from devices and moorings or support structures.

Fish
Monitoring

Installation of ADCPs and turbulence sensors to better understand the baseline tidal flow conditions and hence the change in tidal flow due to presence of the device(s).

Reduce scientific uncertainty.

Tidal Energy Ltd 2008, Aquatera 2017, Ramsey Sound, Tocardo InToTidal at EMEC
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Contamination

Potential for accidental or unplanned events which could lead to contamination of the marine environment.

Fish
Mitigation

Material selection - lubricants, coolants, hydraulic fluids etc. - selected with low ecotoxicity levels and biodegradable.

Reduces/removes risk of contamination/pollution from materials which may have escaped structure.

Use of lower toxicity materials may compromise performance, or impact other technical issues (e.g., fluid changes.)

Foubister 2005, Foubister 2005, MeyGen 2012, Xodus AURORA 2010, DP Energy Ltd. 2013, The Marine Institute 2016, THETIS Energy 2009, EMEC Fall of Warness Grid-Connected Tidal Test Site, MeyGen Tidal Energy Project - Phase I, HS1000 at EMEC, West Islay Tidal Project Energy Park, Galway Bay Test Site, Torr Head Project
Wave, Tidal Operation & Maintenance EMF

Impacts of electromagnetic fields from subsea cables on sensitive species.

Fish
Migratory fish
Design feature

Use of 3-phase cables instead of DC cables.

Reduce the level of EMF to surrounding water column and therefore any potential effects

Potential commercial and technical feasibility issues - the cables used will largely depend upon the project requirements.

Some uncertainty as to the efficacy of this measure.

Wave, Tidal Operation & Maintenance Entanglement

Potential for collision with turbine blades.

Fish
Elasmobranch, large fish
Mitigation

Install a 'detect and shut-down' system using active sonar and other appropriate monitoring equipment.

Could reduce/remove risk of collision with moving blades and enable a route through the consenting process, particulalrly at high sensitivity locations.

Could affect power production, is expensive to implement, and does not help to reduce scientific uncertainty regarding the risk....Read more

Could affect power production, is expensive to implement, and does not help to reduce scientific uncertainty regarding the risk. The reductions in power production, although small, would bring about uncertainty in the investment process and there are questions around impacts of sonar on sensitive species.

Read less
Xodus Group 2019, Davison and Mallows 2005, Magallanes Renovables 2020, Royal Haskoning and Sea Generation (Kyle Rhea) Ltd. 2013, Tidal Lagoon Power 2017, EMEC Billia Croo Grid-Connected Wave Test Site, Strangford Lough - MCT (SeaGen), Kyle Rhea Tidal Stream Array Project, Swansea Tidal Lagoon (SBTL)
Wave, Tidal Operation & Maintenance Underwater noise

The potential effects from underwater noise generated by wave and tidal energy converters.

Fish
Monitoring

Measure noise generated by device(s) during operation to better understand the potential effects on sensitive species.

Measured noise levels can be correlated with threshold values of relevant species and baseline noise levels of the site to determine impact and need for adaptive management measures.

Can be complex and costly to undertake this type of monitoring in high energy environments.

Data and analysis have requirement for acoustic experts.

SIMEC Atlantis Energy Ltd 2011, European Marine Energy Centre (EMEC) 2019, Atlantis Resources Corporation at EMEC, EMEC Billia Croo Grid-Connected Wave Test Site
Tidal Operation & Maintenance Changes in water flow

The potential wider or secondary effects on protected or sensitive sub-littoral seabed due to removal or alteration of energy flow arising from devices and moorings or support structures.

Habitat
Monitoring

Modelling to predict the interaction between changes in tidal flow, flux and turbulence structure and animals.

Reduces scientific uncertainty so appropriate management measures can be employed

Limited management measures available to minimise interaction despite modelling to fully predict interaction

GlaxoSmithKlineMontrose 2012, Orbital Marine Power 2014, Craig 2008, GSK Montrose Tidal Array, OpenHydro Alderney
Wave, Tidal Operation & Maintenance EMF

Impacts of electromagnetic fields from subsea cables on sensitive species.

Habitat
Benthic invertebrates
Design feature

Bundle cables together to reduce field vectors.

Reduce the level of EMF to surrounding water column and therefore any potential effects.

Less redundancy in system.

Potential commercial and technical feasibility issues.

MeyGen 2012, MeyGen Tidal Energy Project - Phase I
Tidal Operation & Maintenance Marine Non-Native Species (MNNS)

Potential for introduction of MNNS which can have an adverse impact on the native species at the site.

Habitat
Mitigation, Design feature

Antifouling application on components such as the pile and rodos blades.

Prevents colonization of the device and structure, avoiding forming a stepping stone for non-native species.

Royal Haskoning and Sea Generation (Kyle Rhea) Ltd. 2013, Orbital Marine Power 2018, Kyle Rhea Tidal Stream Array Project
Tidal Operation & Maintenance Collision risk

Potential for collision with turbine blades.

Marine Mammals
Mitigation, Monitoring, Design feature

Install a 'detect and shut-down' system using active sonar and other appropriate monitoring equipment (e.g., Marine Mammal Detections Sonar System [MMDS]).

Could reduce/remove risk of collision with moving blades and enable a route through the consenting process, particulalrly at high sensitivity locations.

Could affect power production, is expensive to implement, and does not help reduce scientific uncertainty regarding the risk.

Uncertainty around effects of sonar on sensitive species.

Not certain how often ‘shut-downs’ would be required.

...Read more

Could affect power production, is expensive to implement, and does not help reduce scientific uncertainty regarding the risk.

Uncertainty around effects of sonar on sensitive species.

Not certain how often ‘shut-downs’ would be required.

Detection systems are currently insufficient to detect animals (in particular at array scale).

Reductions in power production, although small, would bring about uncertainty in the investment process.

Read less
Harrison et al. 2015, Orbital Marine Power 2010, European Marine Energy Centre (EMEC) 2014, Keenan et al. 2011, Davison and Mallows 2005, Xodus Group 2019, Royal Haskoning and Sea Generation (Kyle Rhea) Ltd. 2013, Aquamarine Power Ltd 2011, Minesto 2016, Magallanes Renovables 2020, Churchill Barriers - Wave Overtopping and Tidal Flow Energy Capture, Pelamis Wave Power P2 Demonstration at EMEC, EMEC Fall of Warness Grid-Connected Tidal Test Site, Strangford Lough - MCT (SeaGen), Strangford Lough - MCT (SeaGen), EMEC Billia Croo Grid-Connected Wave Test Site, Kyle Rhea Tidal Stream Array Project, Oyster 800 at EMEC
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Contamination

Potential for accidental or unplanned events which could lead to contamination of the marine environment.

Marine Mammals
Mitigation, Compliance

Management: Establish and implement a Contamination Control Plan / Ship Oil Contamination Emergency Plans (SOPEPs).

Compliance with International Maritime Organization (IMO) and Maritime Coastguard Agency (MCA) codes for the prevention of contamination.

Reduces risk of any contamination/pollution event and ensures that contingency plans are in place.

Demonstrates compliance with environmental management systems.

Low 2012, Foubister 2005, GlaxoSmithKlineMontrose 2012, MeyGen 2012, Davison and Mallows 2005, Royal Haskoning and Sea Generation (Kyle Rhea) Ltd. 2013, Sustainable Energy Authority of Ireland (SEAI) 2011, The Marine Institute 2016, Federal Energy Regulatory Commission (FERC) 2020, Atlantis Resources Corporation at EMEC, EMEC Fall of Warness Grid-Connected Tidal Test Site, GSK Montrose Tidal Array, MeyGen Tidal Energy Project - Phase I, Strangford Lough - MCT (SeaGen), Kyle Rhea Tidal Stream Array Project, Atlantic Marine Energy Test Site (AMETS), Galway Bay Test Site, PacWave South Test Site
Wave, Tidal Operation & Maintenance Entanglement

Potential for marine animals to become entangled in lost fishing gear or other equipment trapped on infrastructure.

Marine Mammals
Cetaceans
Mitigation

Fisheries management: Agreement with fishermen not to fish near to the device, warning of the dangers of losing equipment.

Reduces potential for entanglement of fishing gear in mooring lines and thus potential for entanglement of marine animals.

Xodus Group 2019, EMEC Billia Croo Grid-Connected Wave Test Site
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Underwater noise

The potential effects from airborne noise from support vessel activity.

Marine Mammals
Mitigation

Adherence to Scotish Marine Wildlife Watching Code (SMWWC).

European Marine Energy Centre (EMEC) 2014, Xodus Group 2019, Magallanes Renovables 2020, European Marine Energy Centre (EMEC) 2020, Aquatera 2017, Laminaria 2018, Orbital Marine Power 2018, EMEC Fall of Warness Grid-Connected Tidal Test Site, EMEC Billia Croo Grid-Connected Wave Test Site, EMEC Scapa Flow Scale Wave Test Site, Tocardo InToTidal at EMEC, EMEC Billia Croo Grid-Connected Wave Test Site
Tidal Operation & Maintenance Changes in water flow

The potential wider or secondary effects on protected or sensitive sub-littoral seabed due to removal or alteration of energy flow arising from devices and moorings or support structures.

Reptiles
Monitoring

Installation of ADCPs and turbulence sensors to better understand the baseline tidal flow conditions and hence the change in tidal flow due to presence of the device(s).

Reduce scientific uncertainty.

Wave, Tidal Operation & Maintenance Entanglement

Potential for marine animals to become entangled in device mooring lines and cables.

Reptiles
Sea turtles
Design feature

Minimise the number of mooring lines.

Reduce risk of entanglement.

Could be a costly measure for technology developers.

Tidal Operation & Maintenance Changes in water flow

The potential wider or secondary effects on protected or sensitive sub-littoral seabed due to removal or alteration of energy flow arising from devices and moorings or support structures.

Benthic
Design feature

Design structures to minimise effect on turbulence structure.

Minimises change in turbulence structure and hence potential interaction.

Can present financial/ logistical/ design challenges to technology developer to alter design of device/ moorings

Aquamarine Power Ltd 2011, Davison and Mallows 2005, Tidal Energy Ltd 2008, Oyster 800 at EMEC, Strangford Lough - MCT (SeaGen), Ramsey Sound
Wave, Tidal Operation & Maintenance EMF

Impacts of electromagnetic fields from subsea cables on sensitive species.

Benthic
Benthic invertebrates
Design feature

Use of 3-phase cables instead of DC cables.

Reduce the level of EMF to surrounding water column and therefore any potential effects.

Potential commercial and technical feasibility issues.

Uncertainty around the need for and efficacy of this measure.

Wave, Tidal Installation, Decommissioning Habitat Loss

Direct loss of protected or sensitive sub-littoral seabed communities due to the presence of devices and associated moorings or support structures on the seabed.

Benthic
Benthic invertebrates, demersal fish
Design feature

Cable protection management measures to ensure that any rock placement that is required will be kept to a minimum to reduce seabed disturbance.

Could reduce effects on sensitive habitats.

Additional cost.

Foubister 2005, RSK Group 2012, Aquamarine Power Ltd 2011, EMEC Fall of Warness Grid-Connected Tidal Test Site, Oyster 800 at EMEC
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Barrier to movement

Potential barrier to movement due to the physical presence of devices and associated moorings/support structures, cables and electrical equipment.

Birds
Mitigation

Adherence to vessel management plan.

Minimizes the potential interaction between animals and construction or maintenance vessels.

OpenHydro and SSE Group 2013, Aquatera 2017, ScottishPower Renewables 2010, Brims Tidal Array, Tocardo InToTidal at EMEC, Sound of Islay Demonstration Tidal Array
Wave, Tidal Installation Collision risk

Potential barrier to movement due to the physical presence of devices and associated moorings/support structures, cables and electrical equipment.

Birds
Monitoring

Array instalation carried out in phases.

Allows close monitoring to observe any unexpected effects.

GlaxoSmithKlineMontrose 2012, GSK Montrose Tidal Array
Wave, Tidal Operation & Maintenance Entanglement

Potential for marine animals to become entangled in device mooring lines and cables.

Birds
Diving birds
Design feature

Cable design with maximum bend radius.

Remove/reduce risk of entanglement

Mooring design driven by technical and commercial consideration.

Wave, Tidal Installation, Operation & Maintenance, Decommissioning Vessel disturbance

Potential for disturbance from project vessels.

Birds
Birds on water
Mitigation

Do not break up or 'flush' rafts of birds.

Reduces potential effects.

Relatively low-cost measure.

Effectiveness of mitigation unclear.

Pertinent to note that the measure is selectively applied to project vessels in context of other vessel operations.

European Marine Energy Centre (EMEC) 2020, Magallanes Renovables 2020, Aquatera 2017, Orbital Marine Power 2018, EMEC Scapa Flow Scale Wave Test Site, Tocardo InToTidal at EMEC
Tidal Operation & Maintenance Changes in water flow

The potential wider or secondary effects on protected or sensitive sub-littoral seabed due to removal or alteration of energy flow arising from devices and moorings or support structures.

Fish
Design feature

Design structures to minimise effect on turbulence structure.

Minimizes change in turbulence structure and hence potential interaction.

Can present financial, logistical, or design challenges to technology developer to alter design of device/moorings.

Aquamarine Power Ltd 2011, Davison and Mallows 2005, Tidal Energy Ltd 2008, Oyster 800 at EMEC, Strangford Lough - MCT (SeaGen), Ramsey Sound
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Contamination

Potential for accidental or unplanned events which could lead to contamination of the marine environment.

Fish
Mitigation

Where rock placement is used, ensure clean rock is used.

Reduces/removes risk of contamination/pollution from materials

Wave, Tidal Operation & Maintenance EMF

Impacts of electromagnetic fields from subsea cables on sensitive species.

Fish
Elasmobranchs
Design feature

Use of 3-phase cables instead of DC cables.

Reduce the level of EMF to surrounding water column and therefore any potential effects.

Potential commercial and technical feasibility issues.

Some uncertainty as to the efficacy of this measure.

Wave, Tidal Operation & Maintenance Entrapment

Potential risk of entrapment within device chambers and mooring arrays.

Fish
Mitigation

Regular ROV/drop down camera surveys to establish occurrence of entrapment.

Early detection of entrapment.

Additional cost.

Wave, Tidal Installation, Operation & Maintenance, Decommissioning Underwater noise

The potential effects from underwater noise generated during installation/ construction (excluding piling).

Fish
Mitigation

Limit vessel speed.

Reduces potential effects.

Relatively low-cost measure.

SIMEC Atlantis Energy Ltd 2011, Atlantis Resources Corporation at EMEC
Tidal Operation & Maintenance Changes in water flow

The potential wider or secondary effects on protected or sensitive sub-littoral seabed due to removal or alteration of energy flow arising from devices and moorings or support structures.

Habitat
Design feature

Site selection.

Minimizes significance of interaction.

ScottishPower Renewables 2012, Ness of Duncansby Tidal Array
Wave, Tidal Operation & Maintenance EMF

Impacts of electromagnetic fields from subsea cables on sensitive species.

Habitat
Benthic invertebrates
Design feature

Bury or HDD cables where possible and viable.

Reduce the level of EMF to surrounding water column and therefore any potential effects.

Reduces 'snagging risk' for vessels.

May have an impact on surrounding benthic habitats and sensitive species.

Uncertainty around the need for and efficacy of this measure.

Can be very challenging or impossible at sites where seabed tends to be rocky.

Additional expense to the project.

...Read more

May have an impact on surrounding benthic habitats and sensitive species.

Uncertainty around the need for and efficacy of this measure.

Can be very challenging or impossible at sites where seabed tends to be rocky.

Additional expense to the project.

Reduced possibility for decommissioning.

Read less
Sustainable Energy Authority of Ireland (SEAI) 2011, Tidal Lagoon Power 2017, Federal Energy Regulatory Commission (FERC) 2020, Atlantic Marine Energy Test Site (AMETS), Swansea Tidal Lagoon (SBTL), PacWave South Test Site
Wave, Tidal Installation, Decommissioning Airborne noise

The potential effects from airborne noise generated during installation/construction (excluding piling).

Marine Mammals
Mitigation

Avoid/limit 'noisy works' within close proximity to sensitive sites (e.g., known seal haul outs and important cliff nesting sites) during sensitive periods, defining appropriate clearance distances where necessary.

Could reduce potential effects on sensitive species during sensitive periods.

Could increase project construction timescales (e.g., if continuous drilling time is restricted or specific periods need to be avoided).

Foubister 2005, SSE Group 2011, ScottishPower Renewables 2012, McGrath 2013, SIMEC Atlantis Energy Ltd 2011, Aquatera 2017, The Marine Institute 2016, Federal Energy Regulatory Commission (FERC) 2020, McGrath 2013, DP Energy Ltd. 2017, EMEC Fall of Warness Grid-Connected Tidal Test Site, Westray South Tidal Project, Fair Head Tidal Array, Atlantis Resources Corporation at EMEC, Tocardo InToTidal at EMEC, Galway Bay Test Site, PacWave South Test Site, Fair Head Tidal Array
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Collision risk

The potential effects from airborne noise from support vessel activity.

Marine Mammals
Seals
Mitigation

Adherence to Scotish Marine Wildlife Watching Code (SMWWC).

European Marine Energy Centre (EMEC) 2014, Xodus Group 2019, European Marine Energy Centre (EMEC) 2020, SSE Group 2011, Magallanes Renovables 2020, Aquatera 2017, Laminaria 2018, Orbital Marine Power 2018, EMEC Fall of Warness Grid-Connected Tidal Test Site, EMEC Billia Croo Grid-Connected Wave Test Site, EMEC Scapa Flow Scale Wave Test Site, Westray South Tidal Project, Tocardo InToTidal at EMEC, EMEC Billia Croo Grid-Connected Wave Test Site
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Contamination

Potential for oil spill incident resulting from the influence of unfavourable weather conditions.

Marine Mammals
Mitigation

Vessel activities to occur in suitable weather conditions.

Reduces the chance for oil spill to the environment.

MeyGen 2012, The Marine Institute 2016, ScottishPower Renewables 2012, MeyGen Tidal Energy Project - Phase I, Galway Bay Test Site, Pelamis Wave Power P2 Demonstration at EMEC
Wave, Tidal Operation & Maintenance Entanglement

Potential for marine animals to become entangled in device mooring lines and cables.

Marine Mammals
Cetaceans
Design feature

Minimise the number of mooring lines.

Reduce risk of entanglement.

Could be a costly measure for technology developers.

Wave, Tidal Installation, Operation & Maintenance, Decommissioning Vessel collision

Potential for collision with project vessels.

Marine Mammals
Cetaceans
Mitigation

Adhere to minimum approach distances for vessels on approach.

Reduces potential effects and is a relatively low cost measure.

Aquamarine Power Ltd 2011, Xodus Group 2019, European Marine Energy Centre (EMEC) 2020, Aquatera 2017, Federal Energy Regulatory Commission (FERC) 2020, Orbital Marine Power 2018, Oyster 800 at EMEC, EMEC Billia Croo Grid-Connected Wave Test Site, EMEC Scapa Flow Scale Wave Test Site, Tocardo InToTidal at EMEC, PacWave South Test Site
Tidal Operation & Maintenance Changes in water flow

The potential wider or secondary effects on protected or sensitive sub-littoral seabed due to removal or alteration of energy flow arising from devices and moorings or support structures.

Reptiles
Design feature

Design structures to minimise effect on turbulence structure.

Minimizeschange in turbulence structure and hence potential interaction.

Can present financial, logistical, or design challenges to technology developer to alter design of device/moorings

Aquamarine Power Ltd 2011, Davison and Mallows 2005, Oyster 800 at EMEC, Strangford Lough - MCT (SeaGen)
Wave, Tidal Operation & Maintenance Entrapment

Potential risk of entrapment within device chambers and mooring arrays.

Reptiles
Mitigation

Release entrapped animal.

Tidal Operation & Maintenance Changes in water flow

The potential wider or secondary effects on protected or sensitive sub-littoral seabed due to removal or alteration of energy flow arising from devices and moorings or support structures.

Benthic
Monitoring

Modelling to predict the interaction between changes in tidal flow, flux and turbulence structure and animals.

Reduces scientific uncertainty so appropriate management measures can be employed.

Limited management measures available to minimise interaction despite modelling to fully predict interaction

Wave, Tidal Operation & Maintenance EMF

Impacts of electromagnetic fields from landfall cables on sensitive species.

Benthic
Benthic invertebrates
Design feature

Limit cable voltage.

MeyGen 2012, MeyGen Tidal Energy Project - Phase I
Wave, Tidal Installation, Decommissioning Habitat Loss

Direct loss of protected or sensitive sub-littoral seabed communities due to the presence of devices and associated moorings or support structures on the seabed.

Benthic
Benthic invertebrates, demersal fish
Mitigation

Use of locally sourced materials, for cable protection, of the same type as the habitat to be disturbed by cable installation.

Minimize impact on biodiversity/ecosystem - lost seabed is replaced with same material and minimizes habitat loss.

Tidal Lagoon Power 2017, Swansea Tidal Lagoon (SBTL)
Wave, Tidal Installation, Decommissioning Changes in sediment dynamics

Reduced visibility impacting prey detection and obstruction avoidance.

Birds
Mitigation

Best practice methodologies to reduce resuspension of sediment during cable burial or device foundation/mooring installation.

Foubister 2005, Sustainable Energy Authority of Ireland (SEAI) 2011, The Marine Institute 2016, Federal Energy Regulatory Commission (FERC) 2020, EMEC Fall of Warness Grid-Connected Tidal Test Site, Atlantic Marine Energy Test Site (AMETS), Galway Bay Test Site, PacWave South Test Site
Tidal Operation & Maintenance Collision risk

Potential for collision with turbine blades.

Birds
Diving birds
Mitigation

Reduce maximum blade tip speed.

Could reduce the likelihood or consequence of potential collision events.

Potential impacts on power production.

Control mechanism of turbine blade speed unclear.

May cause increased fatigue.

Wave, Tidal Operation & Maintenance Entanglement

Potential for marine animals to become entangled in device mooring lines and cables.

Birds
Diving birds
Monitoring

Install tension sensors on mooring lines.

Informs of problem with mooring lines allowing rectification.

Cost per unit.

Additional cost and control system integration requirement.

Load from entangled animal is likely to be smaller than the device loading on the moorings.

Uncertainty of the efficacy of this measure.

Laminaria 2018, EMEC Billia Croo Grid-Connected Wave Test Site
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Vessel disturbance

Potential for disturbance from project vessels.

Birds
Birds on water
Mitigation

Adhere to minimum approach distances for vessels on approach.

Reduces potential effects.

Relatively low-cost measure.

Effectiveness of mitigation is unclear. Further monitoring (e.g., defining of approach distances and then comparing these to see which are most effective) would validate the efficacy of the measure.

Can increase the time of operational procedures and thus increase cost.

Xodus Group 2019, European Marine Energy Centre (EMEC) 2020, DP Energy Ltd. 2017, Aquatera 2017, Federal Energy Regulatory Commission (FERC) 2020, EMEC Billia Croo Grid-Connected Wave Test Site, EMEC Scapa Flow Scale Wave Test Site, Fair Head Tidal Array, Tocardo InToTidal at EMEC, PacWave South Test Site
Tidal Operation & Maintenance Changes in water flow

Modifications to prey distribution and abundance (to include for other receptors) resulting in changes to foraging behaviour.

Fish
Design feature

Design structures to minimise effect on turbulence structure.

Minimizes change in turbulence structure and hence potential interaction.

Can present financial, logistical, or design challenges to technology developer to alter design of device/moorings.

Aquamarine Power Ltd 2011, Davison and Mallows 2005, Tidal Energy Ltd 2008, Oyster 800 at EMEC, Strangford Lough - MCT (SeaGen), Ramsey Sound
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Contamination

Potential for accidental or unplanned events which could lead to contamination of the marine environment.

Fish
Compliance

Management: Establish and implement a Contamination Control Plan/Ship Oil Contamination Emergency Plans (SOPEPs).

Compliance with International Maritime Organization (IMO) and Maritime Coastguard Agency (MCA) codes for the prevention of contamination.

Reduces risk of any contamination/pollution event and ensures that contingency plans are in place.

Demonstrates compliance with environmental management systems.

Foubister 2005, GlaxoSmithKlineMontrose 2012, MeyGen 2012, DP Energy Ltd. 2013, Foubister 2005, Davison and Mallows 2005, Royal Haskoning and Sea Generation (Kyle Rhea) Ltd. 2013, The Marine Institute 2016, Federal Energy Regulatory Commission (FERC) 2020, EMEC Fall of Warness Grid-Connected Tidal Test Site, GSK Montrose Tidal Array, MeyGen Tidal Energy Project - Phase I, West Islay Tidal Project Energy Park, Strangford Lough - MCT (SeaGen), Kyle Rhea Tidal Stream Array Project, Galway Bay Test Site, PacWave South Test Site
Wave, Tidal Operation & Maintenance EMF

Impacts of electromagnetic fields from subsea cables on sensitive species.

Fish
Migratory fish
Design feature

Bundle cables together to reduce field vectors.

Reduce the level of EMF to surrounding water column and therefore any potential effects.

Less redundancy in system.

Potential commercial and technical feasibility issues.

Greater costs associated with not laying direct cable paths.

MeyGen 2012, MeyGen Tidal Energy Project - Phase I
Wave, Tidal Operation & Maintenance Habitat Creation

The introduction of infrastructure and artificial substrates will provide habitat and artificial refuges.

Fish
Monitoring

Monitor near-field behaviours.

Reduces scientific uncertainty around collision risk, displacement, and other impacts.

Increased value/fecundity of commercially important species.

Informs understanding of potential positive impacts from colonisation and use of the project infrastructure.

Can be expensive and difficult to deliver in practice.

May require additional licensing (e.g., echosounders).

European Marine Energy Centre (EMEC) 2014, Xodus Group 2019, Magallanes Renovables 2020, Laminaria 2018, EMEC Fall of Warness Grid-Connected Tidal Test Site, EMEC Billia Croo Grid-Connected Wave Test Site, EMEC Billia Croo Grid-Connected Wave Test Site