Impacts of Open Pen Freshwater Aquaculture Production on Wild Fisheries

Appendix 1 Study Brief

OBJECTIVES

In order to meet the aims of this study the following objectives should be considered:

• Provide an assessment of the evidence on what is known about the impact and impact pathways of the production of salmon smolts and rainbow trout in freshwater lochs on wild salmonids, both from international experience and within Scotland;
• Identify and provide a synthesis of information on the farm sites in Scotland including:
  • A geographical representation.
  • Information on the river systems ¹³³ where farm sites are located.
  • Highlight sites where there is a SAC designation for Atlantic salmon or freshwater pearl mussel.
  • Detail farm output, structure and working practices.
  • What is known about the current and historical restocking practices on those same river systems including restocking with ex farm reared sources.
  • What is the current knowledge on the frequency, cause and timing of drip escapes from these facilities and any documented impact on wild salmonids.
  • What is known about hybridisation in the systems and how much is due to (a) smolt production and (b) restocking practices?
• Using the synthesis of information on farmed sites and knowledge of salmonid population health in river systems where there are no farm sites, is there any evidence to demonstrate that there is a lesser impact on wild stocks within river systems where there are no open pens compared to those with open pens?
• Provide information on what work is being carried out in this field both in the UK and globally and identify gaps in our understanding. Provide an assessment of what future research would need to be carried out to fill these gaps with reference to possible methodologies to address specific problems.
• What are the options for mitigating against any identified impacts and impact pathways and their applicability in Scotland.
• Specifically carry out an investigation of the economic costs and benefits to Scotland, of replacing open pen production, either completely or on all future developments with closed containment systems. Including:
  • the cost implications for the industry, in terms of alternative production methods and supply of smolts.
  • consideration of the benefits or avoided costs, for example in terms of enhanced ecosystem services.
  • an operational timeframe for a phased move away from open pen production to closed/land-based production.
  • Identify whether there is any evidence to support the belief that smolts raised via the closed containment system exhibit lower vigour when transplanted to marine site when compared with open pen produced smolts.

METHODS

It is anticipated that this study will involve a combination of desk based research including a detailed literature review drawing information from all appropriate sources and consultation with experts and stakeholders including scientists, wild fish interests and industry representatives both in Scotland and elsewhere.

• Specifically support will be required from Marine Scotland Science to identify locations of smolt production facilities and status of salmonid populations on relevant river systems.
• Some travel throughout Scotland will be necessary to meet with stakeholders this should be undertaken in a sustainable way making use of audio and video conferencing facilities where appropriate.