Pentland Firth and Orkney Waters Enabling Actions Report: Pentland Firth and Orkney Waters Wave and Tidal Stream Projects and Migratory Salmonids


Title: Pentland Firth and Orkney Waters Enabling Actions Report: Pentland Firth and Orkney Waters Wave and Tidal Stream Projects and Migratory Salmonids
Publication Date:
July 01, 2013
Pages: 150
Sponsoring Organization:
Technology Type:

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Attachment: Access File
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Slaski, R.; Hirst, D.; Gray, S. (2013). Pentland Firth and Orkney Waters Enabling Actions Report: Pentland Firth and Orkney Waters Wave and Tidal Stream Projects and Migratory Salmonids. pp 150.

Epsilon Resource Management was commissioned by The Crown Estate to organise and deliver a workshop on the potential impacts of wave and tidal energy stream developments on migratory salmonids in the PFOW area. The workshop was held in Thurso on the 17th and 18th of April 2013. A Review and Discussion paper (DP) was initially prepared by Epsilon Resource Management, based on literature searches and face to face consultation with developers and key stakeholders and guided by a Review Group appointed by The Crown Estate. The DP was provided to delegates in advance of the workshop, and served to structure the group discussions that comprised the bulk of the workshop.


The overall aim of the Project was to deliver written detail on:

  • The potential impacts from wave and tidal stream developments on migratory fish, taking into account cumulative impacts and considering mitigation measures that might be applicable and practical
  • The current state of knowledge and ‘knowledge gaps’ as to the potential of any of the possible impacts actually having a quantifiable negative effect within the PFOW area
  • The agreed/recommended approach as to how the industry could address the identified key issues/knowledge gaps related to the actual key potential impacts on migratory fish from the PFOW projects.


This report includes the DP (updated since the workshop) and summarises the outcomes from the workshop, identifies key points, and makes several specific recommendations with respect to de-risking the development process. It is recognised that not everyone will agree with all the recommendations, but each of them is based on either a consensus or an overwhelming majority view from the workshop in Thurso.


It is important to carefully read all sections of this report, and particularly the DP summary in Chapter 6 and the workshop summary in Chapter 8.


Key Points:

  1. 17 Scottish rivers are designated as Special Areas of Conservation (SAC) for Atlantic salmon and / or freshwater pearl mussels, and it is the migratory behaviour of Atlantic salmon that potentially causes the concerns that prompted The Crown Estate to organise the Thurso workshop
  2. There is already a good body of knowledge, globally, about possible interactions between wave and tidal stream devices and migratory salmonids (Chapter 4), but there are still some knowledge gaps, and research is underway in order to fill these gaps (Chapter 5)
  3. Of the types of interactions that could occur between wave and tidal energy devices and migratory salmonids, collision, noise and electro-magnetic fields (EMF) are generally considered to be the most important
  4. It was agreed at the workshop that different types of development (whether wave or tidal, or different types of equipment in either category), in different locations, posed different degrees of risk to migratory salmonids, and thus the ‘case by case’ principle to all aspects of consenting was firmly established
  5. There was some recognition that collision was probably the greater risk for some tidal energy stream devices, but the workshop largely concluded that ongoing research into potential noise and EMF interactions is also important
  6. Following from that, it was agreed that there were two main themes for future research and for modelling exercises to consider:
    1. Whether there would be migratory salmonids sufficiently physically co-incident with proposed wave and / or tidal sites for there to be a measurable effect on the fish. This issue was expanded to
      1. Recognise that ‘physically co-incident’ did not necessarily mean physically touching the equipment – effects of noise, EMF and even water turbulence may be important
      2. Take account of temporal variations in presence or absence, i.e. seasonally migrating fish
      3. Also take account of the importance of the genetically distinct seasonal stock components
      4. Take account of the numbers of individuals involved
      5. Take account of other behavioural characteristics such as depth in the water column – i.e. a three dimensional component
    2. Whether, even if there were to be some physical co-incidence, there was actually a mechanism for an impact to occur
  7. Presentations were made to the workshop in relation to the types of research and modelling that are currently being undertaken or developed, and these were broadly welcomed. Difficulties associated with the application of some techniques, such as tagging, in the high energy waters of the PFOW area were acknowledged
  8. There was a strong plea for more collaboration on designing, funding and implementing research, and a wave and tidal energy equivalent of the Offshore Renewables Joint Industry Programmes (ORJIP) initiative was mentioned
  9. The Marine Scotland Licensing Operations Team (MSLOT) approach to consenting was discussed at the workshop, in conjunction with the fact that early projects would deploy small numbers of commercial scale devices. This led to a broad discussion about the nature of the ‘monitoring’ that would be appropriate in order to ascertain whether the devices were having any impact on migratory salmonids – with a clear need to distinguish between monitoring that developers might be asked to implement, and other research / monitoring that should be in the purview of a wider set of industries and/or the public sector bodies
  10. Having established the case by case approach to the consenting process, the workshop considered the degree / scope of information that developers should try to provide in Environmental Statements and similar documents.
  11. It was agreed that in addition to general site information and as much detail as possible (subject to new developments) about the proposed equipment and its emissions / interaction - capabilities, developers should attempt to provide as much baseline information about migratory salmonids in the area as they could reasonably find from existing data sources. Evidencing, as far as possible, an understanding of ‘pathways for possible impacts’ was also considered important
  12. It was also agreed that it was unreasonable to ask developers to attempt to gather new information about migratory salmonids in the area through field or other primary research
  13. Modelling, both particle tracking and collision and / or encounter modelling, was discussed in some detail at the workshop. It was agreed that modelling is a worthwhile approach, but that more data are required in order to increase the accuracy of assumptions made during the modelling process
  14. Improving communications and ensuring the important information is disseminated and taken on board by stakeholders was a consistent theme throughout the workshop, and several examples where improvements might be made were discussed



  1. MSLOT should continue with the consenting approach it has been following
  2. Marine Scotland and others should agree a high-level ‘monitoring approach’ in order to provide developers with greater clarity as to the likely approach to and funding of any monitoring required at their pro jects and will provide stakeholders with a better understanding as to how existing uncertainties will be investigated further
  3. The Crown Estate, Marine Scotland and others should explore the establishment of a wave and tidal equivalent of ORJIP to enable a coordinated approach to be progressed , focused on the key research priorities (including but not exclusively migratory salmonids) for the wave and tidal stream sectors
  4. Marine Scotland Science (MSS) and others should continue to develop and implement research that helps to establish the behaviour and location of migratory salmonids in the PFOW area
  5. The parallel research into mechanisms for interaction and impact should proceed as swiftly as possible
  6. The use of modelling techniques by developers, their advisers and others, should be encouraged, as should their refinement as more data become available
  7. Scoping advice to developers should be clarified, by MSLOT, and offered on a case by case basis
  8. All parties should collaborate more fully on a range of issues, particularly including sharing information and ensuring latest understanding and knowledge is widely disseminated. This will assist with clarifying existing priorities and uncertainties and ensure that aspects which are increasingly well researched and /or understood are acknowledged and the relevant information fully utilised.
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