Management Measures Tool for Marine Energy

OES Environmental Logo

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
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, Magallanes Renovables ATIR at EMEC, EMEC Scapa Flow Scale Wave Test Site, Tocardo InToTidal at EMEC, EMEC Billia Croo Grid-Connected Wave Test Site, Mocean Wave Energy Converter: Blue Horizon
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.

Tidal Energy Ltd 2008, Ramsey Sound
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 Renewables 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.

Foubister 2005, EMEC Fall of Warness Grid-Connected Tidal Test Site
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, Magallanes Renovables ATIR at EMEC, 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.

Tidal Energy Ltd 2008, Ramsey Sound
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.

Foubister 2005, Orbital Marine Power 2010, McPherson 2015, Orbital Marine Power 2018, EMEC Fall of Warness Grid-Connected Tidal Test Site, Nova Tidal Array
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 Bay 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 Renewables 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, 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 Renewables 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, Magallanes Renovables ATIR at EMEC, Tocardo InToTidal at EMEC, EMEC Billia Croo Grid-Connected Wave Test Site, Mocean Wave Energy Converter: Blue Horizon
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 Bay 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, Magallanes Renovables ATIR at EMEC, 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.

Fish
Mitigation

Adherence to Scotish Marine Wildlife Watching Code (SMWWC).

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

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

Habitat
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, South West of England Regional Development Agency (SWDRA) 2006, Magallanes Renovables 2020, Sustainable Energy Authority of Ireland (SEAI) 2011, The Marine Institute 2016, EMEC Fall of Warness Grid-Connected Tidal Test Site, MeyGen Tidal Energy Project - Phase I, Magallanes Renovables ATIR at EMEC, Galway Bay Test Site
Wave, Tidal Operation & Maintenance Habitat Creation

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

Habitat
Monitoring

Monitor near-field behaviours.

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

Increased value/fecundity of commercially important species.

Can be expensive and difficult to deliver in practice.

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

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.

Marine Mammals
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.

ScottishPower Renewables 2012, Ness of Duncansby Tidal Array
Tidal Operation & Maintenance Collision risk

Potential for collision with turbine blades.

Marine Mammals
Mitigation

Install propeller guards.

McGrath 2013, Fair Head Tidal Array
Wave, Tidal Operation & Maintenance Contamination

Potential for oil/hydraulic spill incident resulting from the maintenance activities.

Marine Mammals
Mitigation

All maintenance activities involving oil/hydraulic fluid treatments will be carried out on-shore.

Reduces the chance for oil spill to the environment.

Foubister 2005, EMEC Fall of Warness Grid-Connected Tidal Test Site
Wave, Tidal Operation & Maintenance Entanglement

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

Marine Mammals
Cetaceans
Mitigation

Install strain gauges on the device

Alerts the opertaor in the event of an entanglement event.

Magallanes Renovables 2020, Magallanes Renovables ATIR at EMEC
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Vessel disturbance

Potential for disturbance from project vessels.

Marine Mammals
Mitigation

Reduce speed and maintain steady course when animal is sighted.

Reduces potential effects and is a relatively low cost measure.

Aquamarine Power Ltd 2011, Xodus AURORA 2010, Aquatera Ltd 2011, European Marine Energy Centre (EMEC) 2020, Magallanes Renovables 2020, Royal Haskoning 2012, Aquatera 2017, Tidal Lagoon Power 2017, Federal Energy Regulatory Commission (FERC) 2020, Orbital Marine Power 2018, Oyster 800 at EMEC, HS1000 at EMEC, Wello Penguin at EMEC, EMEC Scapa Flow Scale Wave Test Site, Magallanes Renovables ATIR at EMEC, Oyster 800 at EMEC, Tocardo InToTidal at EMEC, Swansea Bay Tidal Lagoon (SBTL), 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
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 Entrapment

Potential risk of entrapment within device chambers and mooring arrays.

Reptiles
Mitigation

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

Early detection of entrapment.

Additional cost.

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

Site selection.

Minimises 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.

Benthic
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
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

Site selection to avoid sensitive or protected sub-littoral seabed communities.

This could reduce/remove effects on sensitive habitats.

Orbital Marine Power 2014, ScottishPower Renewables 2012, Ness of Duncansby Tidal Array
Wave, Tidal Installation, Decommissioning Changes in sediment dynamics

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

Birds
Mitigation

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

Sustainable Energy Authority of Ireland (SEAI) 2011, The Marine Institute 2016, Federal Energy Regulatory Commission (FERC) 2020, 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

Design proportion of swept area to structure area to minimise collision risk.

This could reduce the likelihood/consequence of potential collision events.

Can be a high cost associated with this.

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

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

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

Birds
Diving birds
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 disturbance

Potential for disturbance from project vessels.

Birds
Shore-nesting birds
Mitigation

Avoidance of sensitive shore nesting areas during sensitive periods with appropriate clearance distance.

Reduces potential effects.

Relatively low-cost measure.

OpenHydro and SSE Renewables 2013, Orbital Marine Power 2014, Foubister 2005, Xodus Group 2019, Magallanes Renovables 2020, Royal Haskoning and Sea Generation (Kyle Rhea) Ltd. 2013, ScottishPower Renewables 2012, Orbital Marine Power 2014, Aquatera 2017, The Marine Institute 2016, THETIS Energy 2009, Orbital Marine Power 2018, Brims Tidal Array, EMEC Fall of Warness Grid-Connected Tidal Test Site, EMEC Billia Croo Grid-Connected Wave Test Site, Magallanes Renovables ATIR at EMEC, Kyle Rhea Tidal Stream Array Project, Tocardo InToTidal at EMEC, Galway Bay 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

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 Installation, Operation & Maintenance, Decommissioning Contamination

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

Fish
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 EMF

Impacts of electromagnetic fields from subsea cables on sensitive species.

Fish
Elasmobranchs
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 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.

Fish
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, ScottishPower Renewables 2012, Laminaria 2018, The Marine Institute 2016, EMEC Fall of Warness Grid-Connected Tidal Test Site, Kyle Rhea Tidal Stream Array Project, EMEC Billia Croo Grid-Connected Wave Test Site, Galway Bay Test Site
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Vessel disturbance

Potential for disturbance from project vessels.

Fish
Elasmobranch, large fish
Mitigation

Reduce speed and maintain steady course when animal is sighted.

Reduces potential effects and is a relatively low cost measure.

Aquatera Ltd 2011, Magallanes Renovables 2020, European Marine Energy Centre (EMEC) 2020, SSE Renewables 2011, Magallanes Renovables 2020, Royal Haskoning 2012, Aquatera 2017, Federal Energy Regulatory Commission (FERC) 2020, Wello Penguin at EMEC, Magallanes Renovables ATIR at EMEC, EMEC Scapa Flow Scale Wave Test Site, Westray South Tidal Project, Oyster 800 at EMEC, Tocardo InToTidal at EMEC, PacWave South Test Site
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Contamination

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

Habitat
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, HS1000 at EMEC, Galway Bay Test Site, Torr Head Project
Wave, Tidal Operation & Maintenance Habitat Creation

The introduction of infrastructure and artificial substrates will provide potential roosting habitat.

Habitat
Roosting birds
Monitoring

Monitor use of device as a roosting platform.

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

Monitoring is relatively inexpensive to carry out.

Data mortgage (data gathered more quickly than it can be analyzed).

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.

Marine Mammals
Design feature

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

Minimizes 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, Davison and Mallows 2005, Oyster 800 at EMEC, Strangford Lough - MCT (SeaGen)
Tidal Operation & Maintenance Collision risk

Potential for collision with turbine blades.

Marine Mammals
Mitigation, Design feature

Install a 'detect and deter' system using a combination of active sonar and acoustic deterrent device (ADD).

Could reduce likelihood of collision with moving blades and enable a route through the consenting process.

Would rely on well proven and reliable system - efficacy of ADDs is unknown in these environments and unknown if deterrent systems will help reduce risk.

Expensive to implement.

Questions around the effects of ADDs (e.g., added noise) on sensitive species.

...Read more

Would rely on well proven and reliable system - efficacy of ADDs is unknown in these environments and unknown if deterrent systems will help reduce risk.

Expensive to implement.

Questions around the effects of ADDs (e.g., added noise) on sensitive species.

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

Further research around ADDs which deter specific groups or species, is underway. This could be useful in deterring specific sensitive species or species groups, at a particular site. For example, University of St Andrews is seveloping an ADD which deter seals, but which don't effect cetaceans.

Read less
Harrison et al. 2015, Orbital Marine Power 2010, Keenan et al. 2011, Aquamarine Power Ltd 2011, THETIS Energy 2009, Churchill Barriers - Wave Overtopping and Tidal Flow Energy Capture, Pelamis Wave Power P2 Demonstration at EMEC, Strangford Lough - MCT (SeaGen), Oyster 800 at EMEC, Torr Head Project
Wave, Tidal Installation Contamination

Accidental release of contaminants during installation including diesel fuel, oil hydraulic fluids, etc.

Habitat
Mitigation

Best practice methodologies to reduce risk of accidental release of contaminants.

Reduces risk of contamination/pollution escaping from structure.

DP Energy Ltd. 2013, West Islay Tidal Project Energy Park
Wave, Tidal Operation & Maintenance Entrapment

Potential risk of entrapment within device chambers and mooring arrays.

Marine Mammals
Mitigation

Release entrapped animal.

Animal may be deceased before they are able to be released.

Tidal Lagoon Power 2017, Swansea Bay Tidal Lagoon (SBTL)
Wave, Tidal Operation & Maintenance Vessel disturbance

Potential for disturbance from project vessels.

Marine Mammals
Mitigation

Use smaller vessels for maintenance purposes.

Reduces potential effects and is a relatively low cost measure.

Aquatera Ltd 2011, Laminaria 2018, Wello Penguin 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
Design feature

Site selection.

Minimizes significance of interaction.

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

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

Reptiles
Monitoring

Monitor near-field behaviours.

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

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

Increased value/fecundity of commercially important species.

Can be expensive and difficult to deliver in practice.

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

Wave, Tidal Installation, Operation & Maintenance, Decommissioning Contamination

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

Benthic
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, Magallanes Renovables 2020, Sustainable Energy Authority of Ireland (SEAI) 2011, Tidal Lagoon Power 2017, The Marine Institute 2016, Aquamarine Power Ltd 2011, EMEC Fall of Warness Grid-Connected Tidal Test Site, MeyGen Tidal Energy Project - Phase I, Kyle Rhea Tidal Stream Array Project, Magallanes Renovables ATIR at EMEC, Atlantic Marine Energy Test Site (AMETS), Swansea Bay Tidal Lagoon (SBTL), Galway Bay Test Site, Oyster 800 at EMEC
Wave, Tidal Operation & Maintenance EMF

Impacts of electromagnetic fields from landfall cables on sensitive species.

Benthic
Benthic invertebrates
Design feature

Use of 3-phase cables instead of DC cables.

Tidal Energy Ltd 2008, Ramsey Sound
Wave, Tidal Installation, Decommissioning Habitat Loss

Seabed habitat disturbance/loss or changes to

seabed habitat

Benthic
Benthic invertebrates, demersal fish
Mitigation

Adherence to vessel anchor and device anchor/mooring plans.

Minimize impact on biodiversity/ecosystem.

Xodus Group 2019, Federal Energy Regulatory Commission (FERC) 2020, EMEC Billia Croo Grid-Connected Wave Test Site, PacWave South Test Site
Tidal Operation & Maintenance Changes in water flow

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

Birds
Diving birds
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.

Aquamarine Power Ltd 2011, Craig 2008, Tidal Energy Ltd 2008, Xodus AURORA 2010, European Marine Energy Centre (EMEC) 2014, Royal Haskoning and Sea Generation (Kyle Rhea) Ltd. 2013, SSE Renewables 2011, Xodus Group 2012, MeyGen 2012, Aquamarine Power Ltd 2011, ScottishPower Renewables 2012, Xodus Group 2012, Oyster 800 at EMEC, OpenHydro Alderney, Ramsey Sound, HS1000 at EMEC, EMEC Fall of Warness Grid-Connected Tidal Test Site, Kyle Rhea Tidal Stream Array Project, Westray South Tidal Project, Costa Head Wave Farm, MeyGen Tidal Energy Project - Phase I, Pelamis Wave Power P2 Demonstration at EMEC
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Contamination

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

Birds
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, 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, Kyle Rhea Tidal Stream Array Project, Magallanes Renovables ATIR at EMEC, Atlantic Marine Energy Test Site (AMETS), Galway Bay Test Site, Torr Head Project
Wave, Tidal Operation & Maintenance Entrapment

Potential risk of entrapment within device chambers and mooring arrays.

Birds
Mitigation

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

Early detection of entrapment.

Additional cost.

Foubister 2005, Orbital Marine Power 2010, McPherson 2015, EMEC Fall of Warness Grid-Connected Tidal Test Site, Nova Tidal Array
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Vessel disturbance

Potential for disturbance from project vessels.

Birds
Birds on water
Mitigation

Vessel transit route: defining routes to avoid sensitive sites and to only disturb one route.

Reduces potential effects.

Relatively low-cost measure.

This is measurable and definable.

OpenHydro and SSE Renewables 2013, DP Energy Ltd. 2013, European Marine Energy Centre (EMEC) 2020, Royal Haskoning and Sea Generation (Kyle Rhea) Ltd. 2013, SSE Renewables 2011, SIMEC Atlantis Energy Ltd 2011, Aquatera 2017, Davison and Mallows 2005, Orbital Marine Power 2018, Brims Tidal Array, West Islay Tidal Project Energy Park, EMEC Scapa Flow Scale Wave Test Site, Kyle Rhea Tidal Stream Array Project, Westray South Tidal Project, Atlantis Resources Corporation at EMEC, Tocardo InToTidal at EMEC, Strangford Lough - MCT (SeaGen)
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
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 Displacement

Potential displacement of essential activities due to the presence of devices and associated moorings/support structures.

Fish
Elasmobranch, large fish
None identified

None identified.

Wave, Tidal Operation & Maintenance EMF

Impacts of electromagnetic fields from subsea cables on sensitive species.

Fish
Migratory fish
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.

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

Additional expense to the project.

Reduced possibility for decommissioning.

Sustainable Energy Authority of Ireland (SEAI) 2011, Tidal Lagoon Power 2017, Federal Energy Regulatory Commission (FERC) 2020, Atlantic Marine Energy Test Site (AMETS), Swansea Bay Tidal Lagoon (SBTL), 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.

Fish
Demersal fish
Design feature

Minimise footprint of anchors/foundations.

Could reduce effects on sensitive habitats

May impact technical considerations.

Aquatera Ltd 2011, Xodus Group 2019, Federal Energy Regulatory Commission (FERC) 2020, Wello Penguin at EMEC, EMEC Billia Croo Grid-Connected Wave Test Site, PacWave South Test Site
Wave, Tidal Operation & Maintenance Vessel disturbance

Potential for disturbance from project vessels.

Fish
Elasmobranch, large fish
Mitigation

Use smaller vessels for maintenance purposes.

Reduces potential effects and is a relatively low cost measure.

Aquatera Ltd 2011, Laminaria 2018, Wello Penguin at EMEC, EMEC Billia Croo Grid-Connected Wave Test Site
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Contamination

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

Habitat
Mitigation

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

Reduces/removes risk of contamination/pollution from materials.

Wave, Tidal Operation & Maintenance Habitat Creation

The introduction of infrastructure and artificial substrates may generate additional habitat diversity.

Habitat
Benthic species
Monitoring

Structure colonization and biofouling surveys.

Informs understanding of potential for increased prey availability and ecological diversity.

Cost associated with monitoring.

Craig 2008, OpenHydro Alderney
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.

Marine Mammals
Mitigation

Adherence to vessel management plan.

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

OpenHydro and SSE Renewables 2013, Aquatera 2017, ScottishPower Renewables 2010, Brims Tidal Array, Tocardo InToTidal at EMEC, Sound of Islay Demonstration Tidal Array
Tidal Operation & Maintenance Collision risk

Potential for collision with turbine blades.

Marine Mammals
Mitigation, Design feature

Install acoustic deterrent devices (ADDs).

Could reduce likelihood of collision with moving blades.

Simpler system than detect and deter.

Efficacy of ADDs in these environments is unknown.

Expensive to implement and it is unknown if deterrent systems will help reduce risk.

Questions around the effects of ADDs (e.g., added noise) on sensitive species and constant deterring means habituation is likely.

...Read more

Efficacy of ADDs in these environments is unknown.

Expensive to implement and it is unknown if deterrent systems will help reduce risk.

Questions around the effects of ADDs (e.g., added noise) on sensitive species and constant deterring means habituation is likely.

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

Read less
Tidal Lagoon Power 2017, THETIS Energy 2009, Swansea Bay Tidal Lagoon (SBTL), Torr Head Project
Wave, Tidal Operation & Maintenance Displacement

Potential displacement of essential activities due to the presence of devices and associated moorings/support structures.

Marine Mammals
Wave, Tidal Operation & Maintenance Entrapment

Potential risk of entrapment within device chambers and mooring arrays.

Marine Mammals
Mitigation

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

Early detection of entrapment .

Additional cost.

Foubister 2005, Orbital Marine Power 2010, McPherson 2015, Project Management Support Services 2006, Orbital Marine Power 2018, EMEC Fall of Warness Grid-Connected Tidal Test Site, Nova Tidal Array, Anglesey Skerries Tidal Stream Array
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Vessel disturbance

Disturbance at seal haul-out sites from project vessels.

Marine Mammals
Seals
Mitigation

Avoid transiting within 500m of known seal haul outs.

Reduces potential effects and is a relatively low cost measure.

SIMEC Atlantis Energy Ltd 2011, Argyll Tidal Limited 2013, Orbital Marine Power 2014, Orbital Marine Power 2010, Magallanes Renovables 2020, Royal Haskoning 2012, Atlantis Resources Corporation at EMEC, Argyll Tidal Demonstrator Project, Pelamis Wave Power P2 Demonstration at EMEC, Magallanes Renovables ATIR at EMEC, 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.

Reptiles
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, Sustainable Energy Authority of Ireland (SEAI) 2011, The Marine Institute 2016, EMEC Fall of Warness Grid-Connected Tidal Test Site, MeyGen Tidal Energy Project - Phase I, Atlantic Marine Energy Test Site (AMETS), Galway Bay 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.

Reptiles
Compliance

Compliance with all relevant guidance (including IMO guidelines) regarding ballast water management and transfer of non-native species.

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

MeyGen 2012, Federal Energy Regulatory Commission (FERC) 2020, MeyGen Tidal Energy Project - Phase I, PacWave South Test Site
Wave, Tidal Installation, Operation & Maintenance, Decommissioning Contamination

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

Benthic
Mitigation

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

Reduces/removes risk of 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, Foubister 2005, Davison and Mallows 2005, 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, Strangford Lough - MCT (SeaGen), Galway Bay Test Site, Torr Head Project
Wave, Tidal Operation & Maintenance EMF

Impacts of electromagnetic fields from subsea cables on sensitive species.

Benthic
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 cost 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 cost to the project.

Reduced possibility of decommissioning.

Read less
Sustainable Energy Authority of Ireland (SEAI) 2011, Federal Energy Regulatory Commission (FERC) 2020, Atlantic Marine Energy Test Site (AMETS), 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.

Benthic
Mitigation

Establish and implement a Biofouling Management Plan.

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

Lack of industry specific guidance.

European Marine Energy Centre (EMEC) 2014, Xodus Group 2019, RSK Group 2012, EMEC Fall of Warness Grid-Connected Tidal Test Site, 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.

Birds
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.

Birds
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.)

MeyGen 2012, Foubister 2005, Xodus AURORA 2010, Davison and Mallows 2005, The Marine Institute 2016, THETIS Energy 2009, MeyGen Tidal Energy Project - Phase I, EMEC Fall of Warness Grid-Connected Tidal Test Site, HS1000 at EMEC, Strangford Lough - MCT (SeaGen), Galway Bay Test Site, Torr Head Project
Wave, Tidal Operation & Maintenance Habitat Creation

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

Birds
Monitoring

Monitor near-field behaviors.

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

Increased value/fecundity of commercially important species.

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

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

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

MeyGen 2012, Tidal Lagoon Power 2017, MeyGen Tidal Energy Project - Phase I, Swansea Bay Tidal Lagoon (SBTL)
Wave, Tidal Decommissioning Vessel disturbance

Potential for disturbance from project vessels.

Birds
Mitigation

Limit use of vessels, e.g. one vessel present with regular use of thrusters to maintain position.

Reduces potential disturbance effects.

Low 2012, MeyGen 2012, Atlantis Resources Corporation at EMEC, MeyGen Tidal Energy Project - Phase I
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

Site selection.

Minimizes significance of interaction.

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

Potential displacement of essential activities due to the presence of devices and associated moorings/support structures.

Fish
Design feature

Site selection (taking into account cumulative impact of other developments).

Minimizes risk of development causing displacement by avoiding migratory routes or other important sites.

ScottishPower Renewables 2012, Ness of Duncansby Tidal Array
Wave, Tidal Installation EMF

Impacts of electromagnetic fields from subsea cables on sensitive species.

Fish
Migratory fish
Design feature

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

Could reduce/remove effects on sensitive habitats.

Relatively low cost measure.

DP Energy Ltd. 2013, ScottishPower Renewables 2012, Laminaria 2018, Tidal Lagoon Power 2017, The Marine Institute 2016, West Islay Tidal Project Energy Park, EMEC Billia Croo Grid-Connected Wave Test Site, Swansea Bay Tidal Lagoon (SBTL), Galway Bay 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.

Fish
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.

DP Energy Ltd. 2013, Federal Energy Regulatory Commission (FERC) 2020, West Islay Tidal Project Energy Park, PacWave South Test Site