SEPA's Sea Lice Regulatory Framework

Footnotes

1 Scottish Environmental Protection Agency (2025) Sea Lice Regulatory Framework Implementation Available at: SEPA – Aquaculture landing page [Accessed 2 October 2025]

2 Scottish Government (2021) Impacts of lice from fish farms on wild Scottish sea trout and salmon: summary of science Available at: Impacts of lice from fish farms on wild Scottish sea trout and salmon: summary of science [Accessed 2 October 2025]

3 Scottish Environmental Protection Agency (2025) Wild Salmonid Protection Zones Available online Map | Scotland's environment web [Accessed: 18 September 2025]

4 Scottish Environmental Protection Agency (2023) Managing interactions between sea lice from finfish farms and wild salmonids: Proposed new regulatory framework. Available at: Managing interactions between sea lice from finfish farms and wild salmonids, Proposed new regulatory framework [Accessed: 18 September 2025]

5 Fisheries Act 2020 [Available at Fisheries Act 2020 Accessed 2 October 2025]

6 Murray, A. G., Moriarty, M. (2021). A simple modelling tool for assessing interaction with host and local infestation of sea lice from salmonid farms on wild salmonids based on processes operating at multiple scales in space and time. Ecological Modelling, 443, 109459.

7 Tucker, C.S., Sommerille, C., Wooten, R., 2001. The effect of temperature and salinity on the settlement and survival of copepodids of Lepeophtheirus salmonis (Krøyer, 1837) on Atlantic salmon, Salmo salar L. Journal of Fish Diseases 23, 309–320.

8 Marine Scotland and Fisheries Management Scotland (2023). Regional and national assessment of the pressures acting on Atlantic salmon in Scotland, 2021. Scottish Marine and Freshwater Science Vol 14 No 4, 22p. DOI:10.7489/12447.

9 Scottish Government (2025) Scottish salmon and sea trout fishery statistics 2024. [Available online: Scottish salmon and sea trout fishery statistics 2024, Accessed 06 October 2025]

10 Harte, A. J., Bowman, A. S., Salama, N.K.G., & Pert, C. C. (2017). Factors influencing the long-term dynamics of larval sea lice density at east and west coast locations in Scotland. Diseases of aquatic organisms, 123(3), 181-192.

11 Pert, C.C., Fryer, R.J., Cook, P, Kilburn, R., McBeath, S., McBeath, A., Matejusova, .I, Urquhart, K., Weir, S.J., McCarthy, U., Collins, C., Amundrud, T., Bricknell, I.R. (2014) Using sentinel cages to estimate infestation pressure on salmonids from sea lice in Loch Shieldaig, Scotland. Aquaculture Environment Interactions 5:49-59

12 Penston, M. J., Davies, I. M. (2009). An assessment of salmon farms and wild salmonids as sources of Lepeophtheirus salmonis (Krøyer) copepodids in the water column in Loch Torridon, Scotland. Journal of Fish Diseases, 32(1), 75-88.

13 Middlemas, S.J., Fryer, R.J., Tulett, D., Armstrong, J.D. (2013) Relationship between sea lice levels on sea trout and fish farm activity in western Scotland. Fisheries Management and Ecology 20, 68–74.

14 Middlemas S.J., Raffell J.A., Hay D.W., Hatton-Ellis M., Armstrong J.D. (2010) Temporal and spatial patterns of sea lice levels on sea trout in Western Scotland in relation to fish farm production cycles. Biology Letters 6, 548-551.

15 Rabe, B., Murray, A. G., Ives, S. C., Moriarty, M., & Morris, D. J. (2024). Searching for sea lice: surveillance to assess environmental infection pressures to model and inform sea lice infestation management. Aquaculture Environment Interactions, 16, 241-262.

16 Salama N.K.G., Dale A.C., Ivanov V.V., Cook P.F., Pert C.C., Collins C.M., Rabe B. (2018) Using biological-physical modelling for informing sea lice dispersal in Loch Linnhe, Scotland. Journal of Fish Diseases 41: 901– 919

17 Sandvik, A.D., Johnsen, I.A., Myksvoll, M.S., Sævik, P.N., Skogen, M.D. (2020) Prediction of the salmon lice infestation pressure in a Norwegian fjord. ICES Journal of Marine Science 77: 746– 756

18 Jones, S. R. M., Revie, C. W., Stewardson, L. (2025). Trends in abundance of sea lice Lepeophtheirus salmonis and Caligus clemensi on juvenile wild Pacific salmon unchanged following cessation of salmon aquaculture in coastal British Columbia. Journal of Fish Diseases, Article e14136. Advance online publication. Trends in Abundance of Sea Lice Lepeophtheirus salmonis and Caligus clemensi on Juvenile Wild Pacific Salmon Unchanged Following Cessation of Salmon Aquaculture in Coastal British Columbia

19 Sveen, L., Fast, M.D., Tengs, T., Kline, R.A., Marti, J.A., Kurian, D., Timmerhaus, G., Vaadal, M., Houston, R.D., Bron, J.E. and Monaghan, S.J., (2025). Local inflammation at the salmon louse (Lepeophtheirus salmonis) attachment site contributes to copepodid rejection in coho salmon (Oncorhynchus kisutch). Cell and tissue research, 401(2) 181-211.

20 Susdorf, R., Salama, N.K.G., Todd, C. D., Hillman, R. J., Elsmere, P., Lusseau, D. (2018). Context-dependent reduction in somatic condition of wild Atlantic salmon infested with sea lice. Marine Ecology Progress Series, 606, 91-104.

21 Shephard, S., MacIntyre, C., Gargan, P. (2016). Aquaculture and environmental drivers of salmon lice infestation and body condition in sea trout. Aquaculture Environment Interactions, 8, 597-610.

22 Thorstad, E. B., Todd, C. D., Uglem, I., Bjørn, P. A., Gargan, P. G., Vollset, K. W., Halttunen, E., Kålås, S., Berg, M., Finstad, B. (2015). Effects of salmon lice Lepeophtheirus salmonis on wild sea trout Salmo trutta a literature review. Aquaculture Environment Interactions, 7(2), 91-113.

23 Ives, S. C., Armstrong, J. D., Collins, C., Moriarty, M., Murray, A. G. (2023). Salmon lice loads on Atlantic salmon smolts associated with reduced welfare and increased population mortalities. Aquaculture Environment Interactions, 15, 73-83.

24 Vollset, K. W., Skår, B., Lennox, R. J., Serra‐Llinares, R. M., Lehmann, G. B. (2025). Salmon Louse Infestation Impairs the Long‐Term Survival of Sea‐Run Brown Trout. Ecology and Evolution, 15(8), e71006.

25 Susdorf, R., Salama, N. K., Lusseau, D. (2018). Influence of body condition on the population dynamics of Atlantic salmon with consideration of the potential impact of sea lice. Journal of Fish Diseases, 41(6), 941-951.

26 Krkošek, M., Revie, C. W., Gargan, P. G., Skilbrei, O. T., Finstad, B., & Todd, C. D. (2013). Impact of parasites on salmon recruitment in the Northeast Atlantic Ocean. Proceedings of the Royal Society B: Biological Sciences, 280(1750), 20122359.

27 Vollset, K. W., Krontveit, R. I., Jansen, P. A., Finstad, B., Barlaup, B. T., Skilbrei, O. T., Krkošek, M., Romunstad, P., Aunsmo, A., Jensen, A. J., Dohoo, I. (2016). Impacts of parasites on marine survival of Atlantic salmon: a meta-analysis. Fish and Fisheries, 17(3), 714-730.

28 Gargan, P. G., Millane, M., Lennox, R. J., Vollset, K. W. (2025). Salmon lice from aquaculture reduce marine survival of Atlantic salmon. Journal of Animal Ecology. 94: 1346-1360

29 Jackson D., Cotter, D., Newell, J., McEvoy, S., O'Donohoe, P., Kane, F., McDermott, T., Kelly, S., Drumm, A. (2013). Impact of Lepeophtheirus salmonis infestations on migrating Atlantic salmon, Salmo salar L., smolts at eight locations in Ireland with an analysis of lice‐induced marine mortality. Journal of Fish Diseases, 36(3), 273-281.

30 Krkošek, M., Revie, C. W., Finstad, B., Todd, C. D. (2014). Comment on Jackson et al. ‘Impact of Lepeophtheirus salmonis infestations on migrating Atlantic salmon, Salmo salar L., smolts at eight locations in Ireland with an analysis of lice-induced marine mortality’. Journal of Fish Diseases, 37(4), 415-417.

31 Jackson D., Cotter, D., Newell, J., McEvoy, S., O'Donohoe, P., Kane, F., McDermott, T., Kelly, S., Drumm, A. (2014). Response to M Krkošek, CW Revie, B Finstad and CD Todd's comment on Jackson et al. ‘Impact of Lepeophtheirus salmonis infestations on migrating Atlantic salmon, Salmo salar L., smolts at eight locations in Ireland with an analysis of lice-induced marine mortality’. Journal of Fish Diseases, 37(4), 419.

32 Skilbrei, O. T., Finstad, B., Urdal, K., Bakke, G., Kroglund, F., Strand, R. (2013). Impact of early salmon louse, Lepeophtheirus salmonis, infestation and differences in survival and marine growth of sea‐ranched Atlantic salmon, Salmo salar L., smolts 1997–2009. Journal of fish diseases, 36(3), 249-260.

33 Larsen, M. L., Vormedal, I., Vollset, K. W. (2024). Negative association of sea lice from fish farms on recreational fishing catches of Atlantic salmon. Journal of Applied Ecology, 61(8), 1772-1783.

34 Vollset, K. W., Skår, B., Lennox, R. J., Serra‐Llinares, R. M., & Lehmann, G. B. (2025). Salmon Louse Infestation Impairs the Long‐Term Survival of Sea‐Run Brown Trout. Ecology and Evolution, 15(8), e71006.

35 Béland K., Séguin, G., Lair, S., (2020) Emamectin benzoate is a safe and effective anthelmintic against coelomic nematode Philometra rubra in striped bass Morone saxatilis. Diseases of Aquatic Organisms. 19,142:47-53.

36 Kent, M.L., Watral, V., Gaulke, C.A., Sharpton, T.J. (2019) Further evaluation of the efficacy of emamectin benzoate for treating Pseudocapillaria tomentosa (Dujardin 1843) in zebrafish Danio rerio (Hamilton 1822). Journal of Fish Diseases. 42(10):1351-1357.

37 Baia, R. R. J., Alves, C. M. G., Malheiros, D. F., Santos, G. G., Tavares-Dias, M. (2024). In vitro efficacy of emamectin benzoate and glyphosate against monogenean parasites from Colossoma macropomum. Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 76(2), 226-234.

38 Kent, A. J., Pert, C. C., Briers, R. A., Diele, K., & Rueckert, S. (2020). Increasing intensities of Anisakis simplex third-stage larvae (L3) in Atlantic salmon of coastal waters of Scotland. Parasites & vectors, 13(1), 62.

39 Mo, T.A., Fossoy, F., Poppe, T.T. (2021). Increasing intensities of Anisakis simplex (Rudolphi, 1809 det. Krabbe, 1878) larvae with weight and sea age in returning adult Atlantic salmon, Salmo salar L., of coastal waters of Norway. Journal of Fish Diseases 44(8): 1075-1089.

40 Wootten, R. W., Yoon, G. H., Bron, J. E. (2010). A Survey of Anisakid Nematodes in Scottish Farmed Salmon-FSAS Project S14008. F. r. 3rd, Institute of Aquaculture, University of Stirling, UK, 1-8.

41 Pardo González, M.Á., Cavazza, G., Gustinelli, A., Caffara, M., Fioravanti, M. (2016) Absence of anisakis nematodes in smoked farmed Atlantic salmon (Salmo salar) products on sale in European countries. Ital Journal of Food Safety. 18, 9(4):8615.

42 Buchmann, K., Mehrdana, F. (2016). Effects of anisakid nematodes Anisakis simplex (sl), Pseudoterranova decipiens (sl) and Contracaecum osculatum (sl) on fish and consumer health. Food and Waterborne Parasitology. 4, 13-22.

43 Whelan, K. and Mo, T.A. (Eds) (2022) Pink Salmon and Red Skin Disease Emerging Threats for Atlantic Salmon. Atlantic Salmon Trust, Blue Book Series, no. 40. Published by: AST, Battleby, Perth, Scotland. 58pp

44 Horbowy, J., Podolska, M., Nadolna-Ałtyn, K. (2016). Increasing occurrence of anisakid nematodes in the liver of cod (Gadus morhua) from the Baltic Sea: does infection affect the condition and mortality of fish?. Fisheries research, 179, 98-103.

45 Aldrin, M., Huseby, R. B., Stige, L. C., Helgesen, K. O. (2023). Estimated effectiveness of treatments against salmon lice in marine salmonid farming. Aquaculture. 575, 739749.

46 Morris D.J., Raynard R.S., Armstrong J.D., Collins C. (2018) SARFSP010-Piloting a network for determining spatial and temporal variation in marine survival of Atlantic salmon and effects of anti-sea lice agents. A study commissioned by the Scottish Aquaculture research forum (SARF). ISBN: 978-1-907266-79-9

47 Scottish Government. (2022). Good Food Nation programme of measures: interim update 2022. Available at: Good Food Nation - programme of measures: interim update 2022 [Accessed 2 October 2025]

48 Scottish Environmental Protection Agency (2023) SEPA's response to consultation feedback. Available at: Managing interactions between sea lice from finfish farms and wild salmonids, SEPA response to consultation feedback [Accessed 3 October 2025]

49 Ministry of Trade, Industry and Fisheries. (2015). Forutsigbar og miljømessig bærekraftig vekst i norsk lakse- og ørret ørretoppdrett Available at: Forutsigbar og miljømessig bærekraftig vekst i norsk lakse- og ørret ørretoppdrett [Accessed 2 October 2025]

50 Eliasen, K., Jackson, D., Koed, A., Revie, C., Swanson, H. A., Turnbull, J., Vanhatalo, J., Visser, A. (2021). An evaluation of the scientific basis of the traffic light system for Norwegian salmonid aquaculture. Research Council of Norway. ISBN 978-82-12-03918-6 (pdf)

51 van Nes, S., Imsland, A. K. D., Jones, S. R. (2025). Salmon lice biology, environmental factors, and smolt behaviour with implications for the Norwegian salmon farming management system: A critical review. Reviews in Aquaculture, 17(1), e12953.

52 Jensen, F., Tveterås, R., & Nielsen, R. (2024). The traffic light system. Is it a solution to a nonpoint pollution problem?. Aquaculture Economics & Management, 28(2), 177-207.

53 Larsen, M. L., & Vormedal, I. (2021). The environmental effectiveness of sea lice regulation: compliance and consequences for farmed and wild salmon. Aquaculture, 532, 736000.

54 Torrissen, O., Jones, S., Asche, F., Guttormsen, A., Skilbrei, O. T., Nilsen, F., Horsberg, T. E., Jackson, D. (2013). Salmon lice - impact on wild salmonids and salmon aquaculture. Journal of Fish Diseases, 36(3), 171-194.

55 Pike, A. W., Wadsworth, S. L. (1999). Sealice on salmonids: their biology and control. Advances in parasitology, 44, 233-337.

56 Code of Good Practice for Scottish Finfish Aquaculture. Available at: Aquaculture, Code of Good Practice [Accessed 2 October 2025]

57 Scottish Government (2019). The Regulation of Sea Lice in Scotland. Topic sheet 71 v4 Available at: Scottish Government (2019). he Regulation of Sea Lice in Scotland. Topic sheet 71 v4 (via internet archiving) [Accessed: 18 September 2025]

58 Boerlage, A. S., Shrestha, S., Leinonen, I., Jansen, M. D., Revie, C. W., Reeves, A., Toma, L. (2024). Sea lice management measures for farmed Atlantic salmon (Salmo salar) in Scotland: Costs and effectiveness. Aquaculture, 580, 740274.

59 Aldrin, M., Huseby, R. B., Stige, L. C., Helgesen, K. O. (2023). Estimated effectiveness of treatments against salmon lice in marine salmonid farming. Aquaculture, 575, 739749.

60 Whyte, S. K., Poley, J. D., Mueller, A., Van Iderstine, C., Fitzpatrick, K. E., Purcell, S. L.,Koop, B.F., Johnson, S.C., Wadsworth, S., Fast, M. D. (2019). Avermectin treatment for Lepeophtheirus salmonis: Impacts on host (Salmo salar) and parasite immunophysiology. Aquaculture, 501, 488-501.

61 Wood, A. T., Taylor, R. S., Quezada-Rodriguez, P. R., & Wynne, J. W. (2021). Hydrogen peroxide treatment of Atlantic salmon temporarily decreases oxygen consumption but has negligible effects on hypoxia tolerance and aerobic performance. Aquaculture, 540, 736676.

62 Vera, L.M., Migaud, H. (2016) Hydrogen peroxide treatment in Atlantic salmon induces stress and detoxification response in a daily manner. Chronobiology International. 33(5):530-42.

63 Overton, K., Dempster, T., Oppedal, F., Kristiansen, T. S., Gismervik, K., Stien, L. H. (2019). Salmon lice treatments and salmon mortality in Norwegian aquaculture: a review. Reviews in Aquaculture, 11(4), 1398-1417.

64 Bui, S., Madaro, A., Nilsson, J., Fjelldal, P. G., Iversen, M. H., Brinchman, M. F., Venås, B., Schrøder, M.B., Stien, L. H. (2022). Warm water treatment increased mortality risk in salmon. Veterinary and Animal Science, 17, 100265.

65 Nilsson, J., Moltumyr, L., Madaro, A., Kristiansen, T. S., Gåsnes, S. K., Mejdell, Gismervik K., Stien, L. H. (2019). Sudden exposure to warm water causes instant behavioural responses indicative of nociception or pain in Atlantic salmon. Veterinary and Animal Science, 8, 100076.

66 Bui, S., Dalvin, S., Vågseth, T., Oppedal, F., Fossøy, F., Brandsegg, H., Jacobsen, Á., á Norði, G., Fordyce, M. J., Michelsen, H. K., Finstad, B., Skern-Mauritzen, R. (2021). Finding the needle in the haystack: Comparison of methods for salmon louse enumeration in plankton samples. Aquaculture Research, 52(8), 3591-3604.

67 Barrett, L., Oldham, T., Kristiansen, T. S., Oppedal, F., Stien, L. H. (2022). Declining size-at-harvest in Norwegian salmon aquaculture: Lice, disease, and the role of stunboats. Aquaculture, 559, 738440.

68 Gharbi, K., Matthews, L., Bron, J., Roberts, R., Tinch, A., Stear, M. (2015). The control of sea lice in Atlantic salmon by selective breeding. Journal of the Royal Society Interface, 12(110), 20150574.

69 Munro L. (2023) Scottish Fish Farm Production Survey 2023. Available at : Scottish Fish Farm Production Survey 2023 [Accessed 18 September 2025]

70 Scottish Government (2024) Wild Wrasse Fishery – 2021/22 Report Available at: Wild Wrasse Fishery – 2021/22 Report [Accessed 18 September 2025]

71 Pritchard, C. J., Salama, N.K.G, Berrill, I., Martin, S. A., Marshall, C. T. (2025). Investigating the relative vulnerability of a temperate coastal fish community to a live wrasse pot fishery. Fisheries Research, 284, 107327.

72 Philis, G., Ziegler, F., Jansen, M. D., Gansel, L. C., Hornborg, S., Aas, G. H., Stene, A. (2022). Quantifying environmental impacts of cleaner fish used as sea lice treatments in salmon aquaculture with life cycle assessment. Journal of Industrial Ecology, 26(6), 1992-2005.

73 Bloodworth, J. W., Baptie, M. C., Preedy, K. F., & Best, J. (2019). Negative effects of the sea lice therapeutant emamectin benzoate at low concentrations on benthic communities around Scottish fish farms. Science of the Total Environment, 669, 91-102.

74 Zhou, X., Bearth, A., Siegrist, M. (2024). Sea lice management in marine-based salmon farming: Public perceptions and acceptance in England and Scotland. Aquaculture, 593, 741267.

75 Murray, A. G., Moriarty, M. (2021). A simple modelling tool for assessing interaction with host and local infestation of sea lice from salmonid farms on wild salmonids based on processes operating at multiple scales in space and time. Ecological Modelling, 443, 109459.

76 Malcolm, I.A., Millar, C.P., Millidine, K.J. (2015). Spatio-temporal variability in Scottish smolt emigration times and sizes. Scottish Marine and Freshwater Science Vol 6 No 2. Edinburgh: Scottish Government, 15pp.

77 The Fish Farming Businesses (Reporting) (Scotland) Order 2020 Available at: The Fish Farming Businesses (Reporting) (Scotland) Order 2020 [Accessed 3 October 2025]

78 Rittenhouse, M. A., Revie, C. W., & Hurford, A. (2016). A model for sea lice (Lepeophtheirus salmonis) dynamics in a seasonally changing environment. Epidemics, 16, 8–16.

79 Scottish Government (2024) Scottish Biodiversity Strategy to 2045. Available at: Scottish Biodiversity Strategy to 2045 [Accessed 3 October 2025]

80 Scottish Environmental Protection Agency (2025) Wild Salmonid Protection Zones Available online Map | Scotland's environment web Accessed: 18 September 2025

81 It is unclear from available public documentation whether this was implemented as of March 2025.

82 It is unclear from available documentation whether this was modified or implemented as described into the final SLRF as of December 2024

83 SEPA (2023) Managing interactions between sea lice from finfish farms and wild salmonids

SEPA response to consultation feedback. [Available online: Managing interactions between sea lice from finfish farms and wild salmonids, SEPA response to consultation feedback Accessed 28 October 2025]

84 Moriarty, M., Ives, S. C., Murphy, J. M., & Murray, A. G. (2023). Modelling parasite impacts of aquaculture on wild fish: The case of the salmon louse (Lepeophtheirus salmonis) on out-migrating wild Atlantic salmon (Salmo salar) smolt. Preventive Veterinary Medicine, 214, 105888.

85 Scottish Environmental Protection Agency (2023) Managing interactions between sea lice from finfish farms and wild salmonids: Proposed new regulatory framework. [Available online: Managing interactions between sea lice from finfish farms and wild salmonids: Proposed new regulatory framework Accessed: 18 September 2025]

86 SEPA (2024) Measurement Assurance and Certification Scotland Performance Standard | Finfish Aquaculture Sea lice surveillance [Available online: Measurement Assurance and Certification Scotland, Performance Standard | Finfish Aquaculture, Sea lice surveillance Accessed 30 October 2025]

87 SEPA (2021) Proposals for a risk-based, spatial framework for managing interaction between sea lice from marine finfish farm developments and wild Atlantic salmon in Scotland. [Available at: Proposals for a risk-based, spatial framework for managing interaction between sea lice from marine finfish farm developments and wild Atlantic salmon in Scotland Accessed 05 November 2025]

88 SEPA (2023) Managing interactions between sea lice from finfish farms and wild salmonids Proposed new regulatory framework. [Available at: Managing interactions between sea lice from finfish farms and wild salmonids, Proposed new regulatory framework Accessed 05 November 2025]

89 SEPA (2023) Managing interactions between sea lice from finfish farms and wild salmonids

SEPA response to consultation feedback [Available at Managing interactions between sea lice from finfish farms and wild salmonids, SEPA response to consultation feedback Accessed 05 November 2025]

90 SEPA (2023) Managing interactions between sea lice from finfish farms and wild salmonids.

SEPA response to consultation feedback: Implications assessment [Available at: Managing interactions between sea lice from finfish farms and wild salmonids, SEPA response to consultation feedback: Implications assessment Accessed 05 November 2025]

91 SEPA (2024) Measurement Assurance and Certification Scotland. Performance Standard.

Finfish Aquaculture. Sea lice surveillance [Available at Measurement Assurance and Certification Scotland, Performance Standard | Finfish Aquaculture, Sea lice surveillance Accessed 05 November 2025]

92 SEPA (2025) Sea lice regulatory framework overview [Available at overview Accessed 05 November 2025]

93 SEPA (2025) SEPA Position Statement. Sea lice regulatory conditions [Available at: SEPA Position Statement. Sea lice regulatory conditions Accessed 05 November 2025]