UHI Research Database pdf download summary Review of the environmental impacts of salmon farming in Scotland Tett, Paul; Benjamins, Steven; Black, Kenny; Coulson, Mark; Davidson, Keith; Fernandes, Teresa F; Fox, Clive; Hart, Mark; Hicks, Natalie; Hughes, Adam; Hunter, D C; Nickell, Thom; Risch, Denise; Tocher, Douglas; Vare, Lindsay; Verspoor, Eric; Wilding, Thomas; Wilson, Ben; Wittich, Anja Publication date: 2018 The Document Version you have downloaded here is: Publisher's PDF, also known as Version of record Link to author version on UHI Research Database Citation for published version (APA): Tett, P., Benjamins, S., Black, K., Coulson, M., Davidson, K., Fernandes, T. F., ... Wittich, A. (2018). Review of the environmental impacts of salmon farming in Scotland. 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Apr. 2019 A CONSORTIUM LED BY REVIEW OF THE ENVIRONMENTAL IMPACTS OF SALMON FARMING IN SCOTLAND Executive Summary and Main Report Issue 01 January 2018 The Scottish Parliament SAMS Research Services Ltd Registered Office: Lismore Suite, Malin House, The European Marine Science Park, Oban, Argyll PA37 1SZ T: +44 (0) 1631 559470 F: +44 (0) 1631 559001 E: [email protected] W: http://www.srsl.com Vat Registration No GB 828 9579 61 Company Registered in Scotland No. SC224404 CONTRIBUTORS The work within this review has been the effort of several researchers, who contributed on areas of their scientific expertise. An outline of the contributors for each section of the review is included below: Section 1 Prof. Paul Tett (SAMS) Section 2 Prof. Eric Verspoor (UHI; Rivers and Lochs Institute) Dr Donna-Claire Hunter (UHI; Rivers and Lochs Institute) Dr Mark Coulson (UHI; Rivers and Lochs Institute) Section 3 Prof. Paul Tett (SAMS) Dr Natalie Hicks (SAMS) Prof. Keith Davidson (SAMS) Section 4 Prof. Teresa Fernandes (Heriot Watt University) Dr Tom Nickell (SAMS SRSL) Section 5 Prof. Eric Verspoor (UHI; Rivers and Lochs Institute) Section 6 Prof. Douglas Tocher (University of Stirling) Section 7 Dr Steven Benjamins (SAMS) Dr Denise Risch (SAMS) Prof. Ben Wilson (SAMS) Ms. Anja Wittich (SAMS SRSL) Dr Clive Fox (SAMS) Section 8 Prof. Paul Tett (SAMS) Prof. Paul Tett is principle author and led the team of researchers who conducted the review. Additional review of the document was undertaken by Prof. Kenny Black, Dr Adam Hughes and Dr Tom Wilding (SAMS). Project Management was undertaken by Dr Lindsay Vare, with additional support from Dr Mark Hart and Dr Chris Allen (SAMS SRSL). This report was produced by a consortium led by SRSL and supported by a number of MASTS institutions for its Customer, The Scottish Parliament, for the specific purpose of providing a review on the environmental impacts of salmon farming in Scotland. This report may not be used by any person other than SRSL’s Customer without its express permission. In any event, SRSL and its consortium partners, accepts no liability for any costs, liabilities or losses arising as a result of the use of or reliance upon the contents of this report by any person other than its Customer. Review of the Environmental Impacts of Salmon Farming in Scotland 02468_0001, Issue 01, 24\01\2018 P a g e | i EXECUTIVE SUMMARY Introduction The lochs, voes and sheltered coastal waters of the Scottish west coast and Western and Northern islands provide ideal conditions for growing salmon in floating cages. The aquaculture industry creates jobs not only on farms but also in upstream and downstream activities such as producing fish feed, in logistical support, and in processing the fish. Nevertheless, its growth during recent decades has encountered economic, societal and environmental challenges, which are likely to increase as the industry expands from 163,000 tonnes in 2016 to about 200,000 tonnes in 2020, with the intention to produce up to 300,000 tonnes in 2030. In 2018 the Rural Economy and Connectivity Committee will be conducting an inquiry into salmon farming in Scotland. To feed into that inquiry the Environmental Climate Change and Land Reform Committee will be considering the current report. Briefing by Scottish Parliament Information Centre (SPICe) on salmon farming in Scotland will also inform both Committees work. This report specifically reviews the scientific evidence relating to the environmental effects of salmon farming. Where the evidence suggests that there are concerns about harm to marine ecosystems or protected species and habitats, possible mitigation measures are suggested. The aim of the research is to carry out a comprehensive literature review to assess and summarise: 1. The environmental impacts of salmon farming in Scotland; 2. The scale of these impacts, and; 3. Approaches to mitigating impact. The environmental impacts were split into six main areas for investigation (as outlined in the research specification issued by The Scottish Parliament, Ref: 2017-18/01/REC). Each of these areas represents a specific issue of concern related to the potential impacts of salmon farming: a. Disease impacts on wild and farmed stocks, including the impact of sea lice; b. The discharge of waste nutrients and their interaction in the wider marine environment, including: i. Solid wastes from cage farms and effects on sediments; ii. Dissolved nutrient inputs and effects on phytoplankton. c. Effects of discharges of medicines and chemicals from salmon farming, including: i. Sea lice medicines; Review of the Environmental Impacts of Salmon Farming in Scotland 02468_0001, Issue 01, 24\01\2018 P a g e | ii ii. Antimicrobial compounds; iii. Metals. d. Escapes from fish farms and potential effects on wild populations; e. Sustainability of feed supplies – including research on plant meal substitution; f. Emerging environmental impacts, including: i. Impact on wild wrasse; ii. Impact on marine mammals. This report was prepared for the Scottish Parliament by a group of subject experts from throughout Scotland. The review focuses on Atlantic salmon, Salmo salar. Reference to 'salmonid' is to any fish of the genera Salmo and Oncorhynchus, i.e. including species of trout and Pacific salmon. The review may be seen as an update of the "Review and Synthesis of the Environmental Impacts of Aquaculture" published in 2002, but which focuses on salmon farming only. Two main sources of evidence were consulted: - Scientific papers published after peer review; - Reports that are in the public domain and that the authors have assessed as reliable. By preference, those studies that were carried out in Scottish waters were used as evidence. However, where these were scarce, evidence has been taken from investigations of salmonid-farming in Norway, Canada, Australia, New Zealand and Chile, and in some cases, from research into the farming of other species of fin-fish in other waters. Section 1 Section 1 provides background information on salmon, salmon farming, sea lice and the marine environment of north-west Scotland and the islands, where most salmon are farmed. It also explains the conceptual framework employed in the review. The activity of salmon farming is likely to generate pressures on natural ecosystems, which may cause change in these systems with consequences for ecosystem services and biodiversity. The scientific literature has been reviewed for evidence of causal links between the pressures and their potential effects on ecosystem state. Effects include those on: - The ecosystem as a whole in which the farm is situated; - Habitats, such as rocky reefs or sea grass beds, which are protected under law or have intrinsic conservation value; - Species protected by law or where there is public opinion favouring their conservation, for example seals or wild salmon. Review of the Environmental Impacts of Salmon Farming in Scotland 02468_0001, Issue 01, 24\01\2018 P a g e | iii The potential impacts of some of these effects depend on spatial scale. For example, effects on species can range from the local scale of a farm (on which sea-bed effects are often obvious), through the intermediate scales of sea-loch and coastal water-bodies, to the largest (up to global) scales of fisheries and markets for salmon feed. Criteria for assessing the significance of effects depend on their scale and also on what is changed. Ecosystems are tolerant of pressures such as organic or nutrient inputs, provided these waste inputs do not exceed the assimilative capacity of these systems. In contrast, any evidenced disturbance to a protected species or habitat was counted as significant. Sections 2 - 7 These sections consider pressures, effects, and mitigations according to the issues identified in the research specifications. The content of each of these reviews are further summarised within this Executive Summary by issue 'Report Cards' (see below, Pages vi - xiv), with contents arranged under three headings: Diagnosis - the significant environmental effects given the present state of affairs; Prognosis - the future state of affairs given current management and regulatory practice, and growth in the industry towards 200,000 tonnes production in 2020 and 300,000 tonnes in 2030; Mitigation - measures, additional to those presently implemented, for which evidence has been reviewed. Section 8 The final section revisits the criteria used to assess the significance of effects.