Scottish Salmon Fish Farming: A Web-Based Process Tracing Analysis of Regulation and Risk Assessment Challenges Relating to Emamectin Benzoate (EmBz) Used in SLICE from Scottish Parliament and Scottish Government Sources Between 2001 and 2025

Abstract

A global debate is underway about how to achieve economic growth, which has led to a push for even greater ‘better regulation’ than already exists in the US and UK, including Scotland. ‘Better regulation’ can include softer regulation, less regulation, or even deregulation. Another regulatory model involves the precautionary principle and there is tension between the two. The ‘better regulation agenda’ has influenced the environmental quality standards adopted for emamectin benzoate in Scottish sea lice treatment. To explore how these complex regulatory models have been used or advocated for and why over 25 years, a process tracing analysis focusing on Scottish Government and Parliament web entries was conducted. Such an analysis has both strengths, providing new perspectives, and weaknesses, regarding the possible quality and extent of information available. The results reveal the ‘better regulation’ model in practice was initially adopted in the 2000s, supported by Scottish Government advisors and implemented by its regulators. Gradually, however, the model was challenged, at times, by researchers, regulators, Members of the Scottish Parliament, environmental non-governmental organizations, and by investigative journalists. This resulted in new environmental quality standards on emamectin benzoate being proposed, then sometimes tightened or blocked. Hence, ‘better regulation’ remains highly influential in the sector, with the fish farming industry able to weaken precautionary policies and enforcement in practice, directly and indirectly.

1. Introduction

Salmon fish farming in Scotland began in 1965 [1,2,3]. Since then, the industry has developed rapidly and become a source of much controversy, as it has elsewhere in the world [4,5,6,7,8,9]. This has focused on fish farm regulation and includes emamectin benzoate (EmBz) use to control sea lice affecting salmon.

Economic growth in the US and UK has recently been openly prioritized by governments over climate, environmental, and sustainability objectives. These governments argue that to achieve growth, it is necessary to reduce or remove regulation, inspection, and enforcement, and cut ‘red tape’. This applies as much to Scottish fish farming as to other sectors [10,11,12]. At times, freedom for all industries to develop unfettered has been advocated. Such solutions are contested, firstly by those who wish to maintain the status quo and secondly by those who wish to see changes to create an alternative means of achieving economic growth. This latter precautionary principle approach requires stronger regulations, improved risk assessments, and quicker and tougher enforcement action against industries perceived to be damaging society through externalizing costs to the environment, health, and sustainability, and affecting ‘decent work’ in some instances. The tension between these approaches is directly relevant to salmon fish farming in Scotland, the use of emamectin benzoate (EmBz) in the veterinary medicine SLICE, and the environmental quality standard (EQS) applied to it.

In December 2004, the Scottish Government set up an ‘Independent Regulatory Review Group “to help Scottish Ministers improve the regulatory environment for businesses”. It was refreshed and relaunched in 2023. This group was and still is influential in shaping the Scottish debate about regulation in Scotland, including fish farming generally, according to its own overview, to quote its better regulation performance document, by

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identifying and trying to fix regulations causing concern for Scottish businesses,

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finding ways of improving the regulatory system,

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advising ministers on all aspects of better regulation,

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acting as an independent and informed judge of the Scottish Government and its regulatory agencies ([13]).

There was no specific mention in 2004 of a role in these ‘aims’ for the group to identify and fix regulations and policies adversely affecting the environment, sustainability, public health, communities, working conditions, animal welfare, or wider society. Only matters of concern to Scottish business were flagged.

The calls for change in fish farm regulation reflect the key ‘theories of change’ outlined above. These have shaped Scottish debate frequently in recent years, whenever regulatory change has been proposed [14]. Evidence has not always resolved the debate, because either evidence at times was lacking or it was heavily contested. Limited public access to data on fish farms in Scotland has been addressed to some extent through the use of a series of Freedom of Information requests (FOIs) from environmental groups and journalists to public bodies about the industry’s regulation and impacts. Although these disclosures appear in the Government web pages, examining Scottish Government and Scottish Parliament material alone can only provide a partial picture of EmBz regulation.

1.1. The Wider Regulatory Problems in the UK Relevant to Scotland

These include ‘analytical failures, intervention failures, co-ordination failures, political failures and regulatory resource failures’ [14,15]. Significant and sometimes systemic failures of UK regulators have been recorded during recent decades. There have been failures of water industry regulators dealing with water pollution (Ofwat), and the environment in England, with Environment Agency (EA) failures on soil, water, and air pollution, and biodiversity loss. The Maritime and Coastguard Agency (MCA) and Health and Safety Executive (HSE) deal with occupational health, safety, and related marine pollution incident across the UK. The MCA deals with regulation and activities on board fish farming vessels at sea, which come under maritime law, and the HSE has regulatory responsibility for work activities at fish cages, and associated moored structures as well as cages on land fall to HSE [16].

Other regulators in public health and environmental health, public analysts, trading standards, and food standards have often had their budgets cut, staffing levels lowered, and expertise watered down [17]. The worst failures have occurred in England. Nevertheless, a number of Scottish investigations, reviews, and policies have failed to explore such failures and frequently followed England down the ‘better regulation’ route without question, giving priority to helping industry rather than ensuring and strengthening public health, worker, consumer, and environmental protections through effective laws, inspections, and enforcement [14]. Whether these regulatory problems have emerged in Scottish salmon fish farming and its use of EmBz therefore merits investigation.

1.2. The State of Past Fish Farming Regulation in Scotland

In 2011, the United Nations Food and Agriculture Organization (FAO) funded a Scottish salmon farming assessment that called for the regulatory environment to be ‘simplified and improved’. It found the industry had ‘highly focused channels to ensure regulatory compliance’ and concluded the industry was ‘heavily regulated, subject to a wide range of legislation that was closely adhered to.’ Industry and Scottish Government cooperation was highlighted, along with the ‘continual pressure from wild fishery interests and environmental groups’ ensuring ‘the search for improvement with regard to such issues as fish health, containment and sea lice control’ was maintained [18]. Some of these observations are contradictory, and evidence from the Scottish Parliament and Scottish Government web searches since 2000 presents a somewhat different picture of regulation and effectiveness.

Other Scottish researchers, in detailed investigations, identified regulation as ‘a bottleneck’ limiting expansion of ‘offshore’ aquaculture generally, as distinct from coastal fish farming, noting inconsistencies in how ‘offshore’ aquaculture is defined. They further observed that regulation ‘must be relevant to the environment, species, and production method’ [19]. In the context of economic ‘expansion’ offshore, such an analysis has validity. However, a range of regulatory problems had already emerged prior to 2022, relevant to both coastal and offshore salmon fish farming, for environmental groups, regulators, workers, and some politicians. The fish farming industry itself appears to have downplayed such problems and instead stressed its economic and employment benefits nationally and locally, arguing their standards and controls were sound and in line with best global regulatory practice [20,21].

Yet, others assessed the regulatory system as ‘light touch’ and in 2018 expected to see more government oversight of the fish farms [22]. Campaigners have questioned the close relationship of the industry with the regulators [23], and by 2023 NGOs were threatening the UK government with legal action over salmon farming’s environmental impacts [24].

1.3. The Alternative Precautionary Principle Approach

The Wingspread precautionary principle brought together four components that underpin regulatory approaches and remain relevant today. These components, in the US, covered “prompt action even in the face of scientific uncertainty, burden of proof and persuasion on proponents of potentially hazardous technologies, assessment of alternatives, and transparency. This broad approach to precaution is in direct conflict with the simplistic, easily manipulated principles and methods of some risk-assessment-based risk management advocated in the US. In contrast to risk assessment, precaution, broadly defined, incorporates the full range of human intelligence in the task of protecting human health and the environment: flexibility, foresight, fairness, thoughtful consideration, and honesty” [25]. If adopted for EmBz controls, there would have been earlier action to manage and reduce exposures. Greater weight would have been given to data gaps and uncertainty in risk assessment, and tougher levels of proof would have been required about the effectiveness of products and the alternatives available, along with tighter regulation of applications.

There are therefore significant competing risk assessments of the Scottish sea lice problem, EmBz applications, and wider environmental impacts between salmon fish farm companies, government, regulators, communities, the food retail industry, environmental groups, local communities, and researchers. The paper is not, however, an in-depth review of the toxicity, detailed environmental impacts, or specific uses of EmBz in Scotland. Nor does the paper examine planning issues surrounding applications for new fish farms or any issues related to farmed salmon releases.

The process tracing used in the paper, a method possibly unfamiliar to many, aims to test a theory relating to a hypothesis about adoption of different models of regulation as well as ‘outcome explaining’. The data are summarized in tables below and in Supplementary Material. These data helped to frame policies and influence outcomes over recent times, for both stronger and weaker regulation and enforcement on sea lice EmBz treatments in the salmon fish farming industry. It should be emphasized that a process tracing analysis is different from a literature review of EmBz toxicity and has different objectives, linked in this case to examining a specific set of policies. The ‘diagnostic’ pieces of evidence look specifically at EmBz and policy outcomes for ‘better regulation’, the precautionary principle, environmental impacts (10), and sustainability, which have become especially intense in 2025.

2. Methods

The process tracing identified how EmBz use relevant to Scottish salmon fish farming was raised in Scottish Government and Scottish Parliament web pages within the period 2001 to 2025 from searches for the term ‘emamectin benzoate’. A documentary analysis was then applied to the information identified, linked to other sources drawn from public disclosure of key documents and policy reviews of the industry. No interviews were conducted. The aim was to explore how two regulatory theories were interpreted by the Scottish Government and Parliament and what outcomes emerged. Only a relatively small number of publicly available official reports and documents on fish farming, and even fewer documents specifically on EmBz, were found to exist on those web pages. This meant that inclusion and exclusions criteria were effectively not relevant, as all web references were examined. The data are presented in later tables and in the Supplementary File. Such a study does not necessitate or lend itself to conventional scientific literature reviews or systematic or rapid reviews. Not all reports, papers, and debates on fish farming from the Scottish Parliament and Scottish Government were searched, because that was not the study focus. Only those relating to EmBz in publicly available official web sources were examined [26,27].

To analyze the material, a process tracing methodology was then adopted [28]. “Process tracing, … is an analytic tool for drawing descriptive and causal inferences from diagnostic pieces of evidence—often understood as part of a temporal sequence of events or phenomena” [29]. It is considered especially useful “for the evaluation of interventions based on theories of change for example, governance and advocacy initiatives, which are difficult to evaluate with experimental and statistical methods” [30]. The method can be used effectively when addressing public health and epidemiology subjects [31]. As the data available are limited in number, this minimizes the possibility of making false assumptions about the specific evidence available and its interpretation.

The approach was therefore germane to a chronological analysis of a range of responses on the regulation and proposed regulation of EmBz in salmon fish farming in Scotland. It provided one means of examining the models of regulatory change outlined in the introduction, the extent to which an iterative approach to ‘changing direction’ emerged, and the reasons for those changes. The hypothesis was that over time the ‘better regulation’ model affecting policy outcomes linked to economic growth, jobs, and profits continued to dominate Scottish fish farm regulation and Scottish Government policy. Pressures from industry to introduce ‘better regulation’ would be significant. Challenges to the model were likely to emerge but, in the model, environmental and sustainability concerns, although recognized, would be downplayed, as would issues relating to fish welfare, food safety, and consumer and worker health and safety.

There are limitations to the process tracing approach that require consideration. These include the quality and extent of the information available to draw causal inferences about the hypothesis, the existence of different hypotheses, and possible missing variables. In practice, however, only two policy models—‘better regulation’ and ‘precautionary principles’—were discussed by Government, industry, and its critics. Within the narrow parameters of the study, no other hypotheses were therefore identified. The status quo did not apply, as policy changes were proposed and debated. Only small numbers of published comments on relevant documents were produced by Government and Parliament in the sources available and over the timeframe that applied to EmBz. Hence, it was possible to assess the quality and extent of the information found. The presence of missing variables that might be revealed by interviews was considered and could be addressed in future studies.

3. Results: EmBz in Scottish Salmon Fish Farming: A Process Tracing Analysis

The results are specifically described under Section 3.1 and Section 3.2 and contained within Table 1, Table 2 and Table 3. Process tracing draws on contextualizing, describing, and framing, where models and related outcomes are identified in data. For additional context, it should be noted that EmBz, in various formulations, has a range of uses on land and in the water as an insecticide and veterinary medicine [32,33]. The use of EmBz on sea lice in the UK was not authorized until 2000 [34]. The toxicity of EmBz is constantly under review. In 2025, a study flagged that long-term exposure impaired reproductive health in adult zebrafish and altered neurodevelopment in their offspring [35]. In addition, there has been relatively limited discussion of alternative treatments to antibiotics and pesticides in aquaculture relating to sea lice—for example, on probiotics—that may be pertinent to policy development and governmental scrutiny [36].

Past analyses of chemicals such as PCBs, dioxins, and pesticides in US and UK farmed salmon centered on how detailed scientific research that did not fit industry interests could be neutralized and how little attention mainstream media paid to the industry’s environmental and welfare impacts [37]. In contrast, the hazards and risks of EmBz have attracted the attention of independent investigative journalists [38] in recent years, often using Freedom of Information inquiries. Some broadsheets too, as early as 2017, were editorializing specifically on the use of SLICE on Scottish salmon fish farms and the need for its independent regulation [39]. This was followed by newspapers raising additional concerns about how effective sea lice regulation was in the industry, whether it was sustainable, how it might affect wild salmon, and how, if at all, fish welfare could be affected [40,41,42]. The industry and industry press, at the same time, presented counterveiling arguments about overregulation and what it saw as its good record on addressing environmental pollution, creating jobs, and contributing significantly to the Scottish economy [20,21,43,44,45,46]. These reports and civil society accounts, often using FOIs and other ‘validated’ data, later provided a rough triangulation to test how accurate official web sources were in informing policy debates and reflecting the concerns of all groups involved in or concerned about salmon fish farming’s use of EmBz.

3.1. Scottish Government Process Tracing

The first reference to EmBz and sea lice on the Scottish Government web site surprisingly did not come until 2012, twelve years after its first UK authorization. The process tracing analysis tabulated below describes the Scottish Government position on EmBz in its web pages. This moved from accepting the use of EmBz on sea lice in 2012, to noting precautionary concerns about ways to reduce sea lice impacts in 2015, to reluctantly acknowledging researcher concerns about transparency regarding high EmBz and the role of various regulators in 2017, through to providing information on residue testing and regulatory responses between 2017 and 2024, and finally accepting the need for new EmBz standards and regulations, which then appear to have been significantly neutralized in practice by Government.

The initial hypothesis was that ‘better regulation’ would determine Government policy on EmBz and precautionary policies would be marginalized or neutralized to support the fish farming position. Over time, the tracing shows this happened in the 2010s and 2020s. Responses proved more nuanced, perhaps due to Scottish Parliamentary debates and mainstream media coverage of EmBz use, but Government and its advisors remained committed to ‘better regulation’ policies and resistance to precautionary policy proposals on the fish farming industry in general and EmBz use in particular.

The tracing shows too how external pressures partly generated by FOIs and pressure from the Scottish Parliament explain some movements away, at least on paper, from ‘better regulation’ outcomes to more precautionary considerations and tougher regulation. This happened in 2017, 2018, 2020, and 2024, and would almost certainly have had a role in triggering the wider consultation in 2023 and 2024.

Table 1. Chronological process analysis summary of key Scottish Government EmBz web entries relating to fish farm use 2012–2025.

Date	Subject
2012	Open Pen Freshwater Aquaculture Production on Wild Fisheries. Report. Marine Scotland commissioned report explored ways of reducing possible sea lice impacts of freshwater aquaculture on wild salmon
2015	Report of case study mentioning EmBz environmental persistence concerns
2017	FOI requests. Information on Merck and EmBz used in salmon farming. Researchers sought report transparency, noted very high EmBz level on seabed not near fish farms long after treatment and links with crustacea declines (2016). SEPA commissioned independent research on environmental quality standard (EQS) for EmBz
2017	FOI. Information on EmBz in fish farming: Looks at residue testing, roles of VMD, Marine Scotland’s Fish Health Inspectorate, and industry/regulator responses
2018	FOI. SEPA board meeting regarding EmBz: Response on application of new EmBz EQS by SEPA
2020	FOI. Information request. Field trials of Imidacloprid (Ectosan/BMK08) by salmon farming industry, including fish farm site result for EmBz residue taken by Marine Scotland’s Fish Health Inspectorate during program for residue testing
2020	Independent Report. Above result generated two mentions of EmBz on in-feed issues, one from ecoinvent and one from an expert opinion
2020	FOI. Requesting information about EmBz use on wellboats and salmon farming
2023/ 2024	EmBz EQS following 2023 consultation on EmBz EQS on new tougher standard. Views sought on SEPA timescale to apply standard, SEPA to plan implementation/enforcement of regulations, as its work was based on best available science/used independent research. 2022 Griggs report had appeared
2023	Scottish Aquaculture Council chair. Scottish Minister for Rural Affairs. Working closely with SEPA to develop sea lice risk assessment and so plans for National Marine Plan 2 (NMP2) on new EQS for EmBz. Continue close working with coastal communities/industries to develop proposals for enhanced marine protection
2023/2024	Scottish Animal Welfare Commission Review. October 2023. Independent report in October 2024 noted technical changes to permitted sea lice discharge control of EmBz justified by need to reduce pesticide environmental hazards and welfare consequences in marine finfish cages. Used latest evidence of EmBz environmental persistence. Scottish Government adopted UKTAG recommendation for EQS to reduce EmBz discharge limits
2023	Farmed fish health: Scotland’s Farmed Fish Health Framework group minutes from 2021/22. Notes lack of clarity on progress in UKTAG review on EmBz
2024	FOIs and Environment Strategy for Scotland. Looked at how Scottish Government could use existing policy levers on the economy to help tackle the climate and nature emergencies. Costs of consultations discussed
2025	Scottish Cabinet Secretary response to Scottish Parliament Rural Affairs Committee on sea lice controls and regulation (elsewhere on web pages)

FOIs—Freedom of Information responses. SEPA—Scottish Environment Agency. UKTAG—UK Technical Advisory Group. EQS—Environmental Quality Standard. VMD—Veterinary Medicines Directorate. https://www.gov.scot/search/?cat=sitesearch&q=Emamectin+benzoate (accessed 6 June 2025).

Table 1. Chronological process analysis summary of key Scottish Government EmBz web entries relating to fish farm use 2012–2025.

Date	Subject
2012	Open Pen Freshwater Aquaculture Production on Wild Fisheries. Report. Marine Scotland commissioned report explored ways of reducing possible sea lice impacts of freshwater aquaculture on wild salmon
2015	Report of case study mentioning EmBz environmental persistence concerns
2017	FOI requests. Information on Merck and EmBz used in salmon farming. Researchers sought report transparency, noted very high EmBz level on seabed not near fish farms long after treatment and links with crustacea declines (2016). SEPA commissioned independent research on environmental quality standard (EQS) for EmBz
2017	FOI. Information on EmBz in fish farming: Looks at residue testing, roles of VMD, Marine Scotland’s Fish Health Inspectorate, and industry/regulator responses
2018	FOI. SEPA board meeting regarding EmBz: Response on application of new EmBz EQS by SEPA
2020	FOI. Information request. Field trials of Imidacloprid (Ectosan/BMK08) by salmon farming industry, including fish farm site result for EmBz residue taken by Marine Scotland’s Fish Health Inspectorate during program for residue testing
2020	Independent Report. Above result generated two mentions of EmBz on in-feed issues, one from ecoinvent and one from an expert opinion
2020	FOI. Requesting information about EmBz use on wellboats and salmon farming
2023/ 2024	EmBz EQS following 2023 consultation on EmBz EQS on new tougher standard. Views sought on SEPA timescale to apply standard, SEPA to plan implementation/enforcement of regulations, as its work was based on best available science/used independent research. 2022 Griggs report had appeared
2023	Scottish Aquaculture Council chair. Scottish Minister for Rural Affairs. Working closely with SEPA to develop sea lice risk assessment and so plans for National Marine Plan 2 (NMP2) on new EQS for EmBz. Continue close working with coastal communities/industries to develop proposals for enhanced marine protection
2023/2024	Scottish Animal Welfare Commission Review. October 2023. Independent report in October 2024 noted technical changes to permitted sea lice discharge control of EmBz justified by need to reduce pesticide environmental hazards and welfare consequences in marine finfish cages. Used latest evidence of EmBz environmental persistence. Scottish Government adopted UKTAG recommendation for EQS to reduce EmBz discharge limits
2023	Farmed fish health: Scotland’s Farmed Fish Health Framework group minutes from 2021/22. Notes lack of clarity on progress in UKTAG review on EmBz
2024	FOIs and Environment Strategy for Scotland. Looked at how Scottish Government could use existing policy levers on the economy to help tackle the climate and nature emergencies. Costs of consultations discussed
2025	Scottish Cabinet Secretary response to Scottish Parliament Rural Affairs Committee on sea lice controls and regulation (elsewhere on web pages)

FOIs—Freedom of Information responses. SEPA—Scottish Environment Agency. UKTAG—UK Technical Advisory Group. EQS—Environmental Quality Standard. VMD—Veterinary Medicines Directorate. https://www.gov.scot/search/?cat=sitesearch&q=Emamectin+benzoate (accessed 6 June 2025).

The first Scottish Government mention of EmBz in the web pages discussed issues involved in reducing sea lice on wild salmon. There followed a series of Freedom of Information (FOI) disclosures, without which our understanding of how Government, industry, and regulators dealt with EmBz would be incomplete and our knowledge of regulation, standards, and enforcement would be missing, as would the sporadic nature of efforts to raise quality standards for EmBz use or its removal altogether. Later mentions broadened out to include concerns about environmental persistence and researchers who feared their research could be compromised by a lack of transparency, as well as concerns about residue impacts. The roles of ‘regulators’ like the SEPA then became more closely scrutinized as the original environmental quality standards for EmBz were revised, tightened, delayed, and then debated further by the key parties, linked to discussions about the best available evidence and its application. Animal welfare concerns remained strong. A lack of clarity about the standards and their implementation also emerged.

The process therefore revealed growing concerns about EmBz use and contested risk assessments. The Scottish Government and its agencies sometimes sought independent research on quality standards and consulted with industry and other parties, including environmental groups, about the way forward. Table 2 shows how the environmental quality standards for EmBz shifted over the years. Science continually refines and revises its risk assessments based on available data, along with mechanisms of toxicity. In contrast, policy makers and industry advocates may often, in practice, present risk assessments and quality standards as fixed and always entirely safe. Information provided within the Scottish Government web pages reveals how flawed such an approach was. It would have led environmental and welfare groups to further question the margins of error built into risk assessments and how EmBz quality standards in 1999 could have been tightened over the years and then challenged and revised.

The results provide a strong indication that the ‘better regulation’ model proposed for the fish farming industry was deficient, and that the processes it used for consultation and outcomes were flawed and did not give sufficient weight to the precautionary principle and the tentative nature of some of the research findings on EmBz. The changes in fish farm EmBz regulatory policy in the 2020s illustrate this in Table 2. The Scottish Government was constantly challenged to reconcile industry concerns with regulatory requirements, standards, enforcement, and demands from wild fishing and environmental groups for greater controls or bans. The 1999 standard was recommended to be tightened only in 2016, after new research. The fish farming industry and pesticide manufacturers were then consulted, and the recommended standard loosened significantly by 2019, apparently accepted by the regulator and put in force. More consultation including industry input led to a recommendation in 2022 that the standard be loosened again. By 2023, even greater loosening was recommended after the Scottish Government had paused consultations on the standard.

Table 2. Scottish Government table and chronology on EmBz EQS threshold changes/proposed changes 1999–2025.

Date	Standard in Force (If) or Recommended (r)	Organization
1999	763 ng/kg wet weight (if) equivalent to approximately 1520 ng/kg dry weight	SEPA
2016	12 ng/kg of sediment dry weight (r)	Independent organization, WRc commissioned by SEPA
2019	Minimum standards 23.5 ng/kg of sediment dry weight (r)	UKTAG in consultation with the industry, and vet medicine manufacturer
2019	New interim regulatory position based on an interim standard of 23.5 ng/kg of sediment dry weight (if)	SEPA
2022	131 ng/kg sediment (dry weight) (r)	UKTAG.
2023	Salmon Scotland alerted UK TAG about a possible error in EQS EmBz calculation, error confirmed by UKTAG	Scottish Government paused its consultation on EQS for EmBz
2023	New recalculated recommended EQS for marine sediment therefore changed from 131 ng/kg dry weight to 272 ng/kg dry weight.

(Source. Scottish Government. Background and rationale for new EQS standards for EmBz 24 April 2023 Consultation Paper). SEPA—Scottish Environment Agency. UKTAG—UK Technical Advisory Group. EQS—Environmental Quality Standard. WRc—Water Research Centre. https://www.gov.scot/publications/new-environmental-quality-standard-eqs-emamectin-benzoate-embz-consultation-implementation-timescales/pages/2/ (accessed 5 June 2025).

Table 2. Scottish Government table and chronology on EmBz EQS threshold changes/proposed changes 1999–2025.

Date	Standard in Force (If) or Recommended (r)	Organization
1999	763 ng/kg wet weight (if) equivalent to approximately 1520 ng/kg dry weight	SEPA
2016	12 ng/kg of sediment dry weight (r)	Independent organization, WRc commissioned by SEPA
2019	Minimum standards 23.5 ng/kg of sediment dry weight (r)	UKTAG in consultation with the industry, and vet medicine manufacturer
2019	New interim regulatory position based on an interim standard of 23.5 ng/kg of sediment dry weight (if)	SEPA
2022	131 ng/kg sediment (dry weight) (r)	UKTAG.
2023	Salmon Scotland alerted UK TAG about a possible error in EQS EmBz calculation, error confirmed by UKTAG	Scottish Government paused its consultation on EQS for EmBz
2023	New recalculated recommended EQS for marine sediment therefore changed from 131 ng/kg dry weight to 272 ng/kg dry weight.

(Source. Scottish Government. Background and rationale for new EQS standards for EmBz 24 April 2023 Consultation Paper). SEPA—Scottish Environment Agency. UKTAG—UK Technical Advisory Group. EQS—Environmental Quality Standard. WRc—Water Research Centre. https://www.gov.scot/publications/new-environmental-quality-standard-eqs-emamectin-benzoate-embz-consultation-implementation-timescales/pages/2/ (accessed 5 June 2025).

This Government response could paradoxically be viewed either as an example of effective precautionary policy in action or as a de facto deregulatory policy that limited effective enforcement, delayed or weakened by objections from industry about tougher standards being imposed and unfair inspections. Perhaps it was an example of both approaches, but the prolonged delays in adopting standards and the controversies about implementation showed how deeply embedded ‘better regulation’ approaches were and how industry obtained far greater access to politicians and regulators than environmental groups and other NGOs.

3.2. Scottish Parliament Process Tracing

The results from the analysis are tabulated below and describe the Scottish Parliament responses to the use of EmBz on sea lice that were relevant to testing the hypothesis on better regulation and related ‘outcome explaining’. Unlike the Scottish Government, the Parliament contained parliamentarians who represented constituents critical of the fish farming industry or its rapid expansion and who came from political parties unsympathetic to the government. More questioning of policy resulted and this translated into even greater support for precautionary approaches to sea lice treatments and less support for ‘better regulation’ or soft touch policies to benefit industry. The initial hypothesis again was that better regulation would determine policy and that precautionary policies would be marginalized or neutralized to support the fish farming position on wanting to use EmBz. Tracing through the responses listed in Table 3 reveals how the process produced increasingly critical and wider assessments of policy over time, partly due to the later involvement of Scottish Parliamentary committees on rural affairs, net zero, energy, land reform, and environmental issues.

Specifically concerns about EmBz discharges, residues, and environmental impacts were constantly raised but not resolved between 2001 and 2025. This showed Parliament had perhaps a greater focus on looking at policy outcomes as opposed to Government ‘statements’. The effectiveness of EmBz was questioned in 2009, 2011, 2017, and 2018. More, very specific concerns about regulation began to appear in 2022 and continued until 2025. Economic impacts on the fish farming industry were raised throughout the tracing period and increased between 2023 and 2025. By 2025, Parliamentary committees and Government were receiving letters that explicitly wanted a rigorous precautionary policy speedily applied to EmBz use.

Hence, similar concerns to those raised within the Scottish Government web pages about EmBz emerged in the Scottish Parliament web pages but reflected even more precautionary principle thinking. It is significant that the concerns first appeared in the Scottish Parliament twelve years earlier in 2000 and soon focused on discharges, residues, efficacy, testing, and licensing of EmBz throughout the 2000s and their possible adverse effects. Some MSPs indirectly drew on FOI data submitted to the Scottish Government on the subject.

Table 3. Chronological process analysis of key Scottish Parliament EmBz (SLICE) web entries 2000–2025. Sixty-five references to EmBz in fish farming, mainly in committees on rural affairs, net zero, energy, and transport, and debates at Holyrood and Q and As from MSPs.

Date	Topic
2000	Questions on approval times for use on fish farms.
2001	Questions about discharges and testing related to licensing. Reassurances given.
2002	More discharges/testing and licensing questions. More reassurances given.
2005	Questions raised about human consumption levels of the pesticide’s residues.
2009	Question citing Chilean, Canadian, American, Norwegian research showing EmBz treatments to control sea lice on salmon ‘decreasingly effective’ and questions on what actions would be taken and with what guidance.
2011	More questions raised about the effects of EmBz.
2017	More questions raised regarding rising EmBz use on salmon farms. Noted that SEPA kept the evidence on the impacts of EmBz under review. Debates occurred on fish farm regulation in Scottish Parliament
2018	EmBz EQS discussed in Environment, Climate Change & Land Reform Committee. During 2018, this committee and the Rural Economy and Connectivity Committee discussed EmBz and its half-life in sediment. Debates occurred on fish farm regulation in Scottish Parliament.
2019	“Growing concerns” raised about EmBz use, which SEPA research concluded “is significantly impacting local marine environments”.
2020	Concerns from 2019 continued throughout 2020 and were also raised in the Rural Economy and Connectivity Committee.
2022	Further questions raised about SEPA’s interim regulatory position on EmBz. Griggs reported
2023 March	Questions raised on Scottish Association of Marine Science report, unexpected EmBz impact on wild crustaceans and if fish farm EmBz phase out planned.
2023 April/May	Cabinet Secretary reported Scottish Government had begun a consultation on the implementation and business impact of the new Environmental Quality Standard for EmBz recommended by the UKTAG.
2024 June	Rural Affairs and Islands Committee further discussed the EQS for EmBz, noting “ Scottish Sea Farms, the second-largest producer, doubled its use of EmBz from 2018 to 2023. It is definitely a concern”.
2024 November	EmBz usage continued to be discussed in Parliament. Some raised concerns regarding regulatory changes taking many years to introduce and could delay effective action. Others noted regulation had come in to reduce discharges.
2024	Parliament informed 2023 inquiry had received SEPA letter allowing 196 existing salmon farms to continue discharging the same quantities of EmBz as before.
2025 January	Rural Affairs & Islands Committee called for immediate timetable to address concerns about Scottish salmon farming industry’s long-term viability. Government asked to consider expedited timetable for introducing a revised EmBz EQS, rather than the planned four-year implementation period.
2025 February	Lord Dundonald letter to Rural and Island Affairs Committee noted delay in implementing EmBz standard, contrary to the Precautionary Principle and so allowing continued harm to crustaceans and benthic ecosystems. Wanted speedier action and stricter penalties for non-compliance, and observed EmBz was first identified as a serious environmental threat over 16 years ago.
2025 March	Cabinet Secretary responded to the Committee’s concerns about the proposed four-year implementation period for the introduction of a revised environmental quality standard for EmBz given the environmental risks from the chemical.

UKTAG—UK Technical Advisory Group. EQS—Environmental Quality Standard. SEPA—Scottish Environment Agency. https://www.parliament.scot/search?qry=Emamectin+benzoate (accessed 5 June 2025).

Table 3. Chronological process analysis of key Scottish Parliament EmBz (SLICE) web entries 2000–2025. Sixty-five references to EmBz in fish farming, mainly in committees on rural affairs, net zero, energy, and transport, and debates at Holyrood and Q and As from MSPs.

Date	Topic
2000	Questions on approval times for use on fish farms.
2001	Questions about discharges and testing related to licensing. Reassurances given.
2002	More discharges/testing and licensing questions. More reassurances given.
2005	Questions raised about human consumption levels of the pesticide’s residues.
2009	Question citing Chilean, Canadian, American, Norwegian research showing EmBz treatments to control sea lice on salmon ‘decreasingly effective’ and questions on what actions would be taken and with what guidance.
2011	More questions raised about the effects of EmBz.
2017	More questions raised regarding rising EmBz use on salmon farms. Noted that SEPA kept the evidence on the impacts of EmBz under review. Debates occurred on fish farm regulation in Scottish Parliament
2018	EmBz EQS discussed in Environment, Climate Change & Land Reform Committee. During 2018, this committee and the Rural Economy and Connectivity Committee discussed EmBz and its half-life in sediment. Debates occurred on fish farm regulation in Scottish Parliament.
2019	“Growing concerns” raised about EmBz use, which SEPA research concluded “is significantly impacting local marine environments”.
2020	Concerns from 2019 continued throughout 2020 and were also raised in the Rural Economy and Connectivity Committee.
2022	Further questions raised about SEPA’s interim regulatory position on EmBz. Griggs reported
2023 March	Questions raised on Scottish Association of Marine Science report, unexpected EmBz impact on wild crustaceans and if fish farm EmBz phase out planned.
2023 April/May	Cabinet Secretary reported Scottish Government had begun a consultation on the implementation and business impact of the new Environmental Quality Standard for EmBz recommended by the UKTAG.
2024 June	Rural Affairs and Islands Committee further discussed the EQS for EmBz, noting “ Scottish Sea Farms, the second-largest producer, doubled its use of EmBz from 2018 to 2023. It is definitely a concern”.
2024 November	EmBz usage continued to be discussed in Parliament. Some raised concerns regarding regulatory changes taking many years to introduce and could delay effective action. Others noted regulation had come in to reduce discharges.
2024	Parliament informed 2023 inquiry had received SEPA letter allowing 196 existing salmon farms to continue discharging the same quantities of EmBz as before.
2025 January	Rural Affairs & Islands Committee called for immediate timetable to address concerns about Scottish salmon farming industry’s long-term viability. Government asked to consider expedited timetable for introducing a revised EmBz EQS, rather than the planned four-year implementation period.
2025 February	Lord Dundonald letter to Rural and Island Affairs Committee noted delay in implementing EmBz standard, contrary to the Precautionary Principle and so allowing continued harm to crustaceans and benthic ecosystems. Wanted speedier action and stricter penalties for non-compliance, and observed EmBz was first identified as a serious environmental threat over 16 years ago.
2025 March	Cabinet Secretary responded to the Committee’s concerns about the proposed four-year implementation period for the introduction of a revised environmental quality standard for EmBz given the environmental risks from the chemical.

UKTAG—UK Technical Advisory Group. EQS—Environmental Quality Standard. SEPA—Scottish Environment Agency. https://www.parliament.scot/search?qry=Emamectin+benzoate (accessed 5 June 2025).

Some parliamentarians were also guided by information from SEPA later in the 2010s, regarding EmBz having a significant impact on the environment. Scottish Parliamentary Committees like the Environment, Climate Change & Land Reform Committee and the Rural Economy and Connectivity Committee also increased their activity in the 2020s and interest in sea lice treatments. These Committees reflected a broader range of interests and greater urgency in wishing to address EmBz use than the Scottish Government web site revealed. MSPs, in their work, would be approached by fish farm companies, rural communities, and environmental groups wanting to make their views known. Some evidence to the Parliamentary committees explicitly drew on the precautionary principle when assessing EmBz use and recognized many years had elapsed between the pesticide’s first introduction and continued delays in the control of its environmental risks in 2025. This contrasts starkly with the Better Regulation Review sought by the Scottish Government on regulating fish farming and offered by its principal advisor, as the discussion below demonstrates.

4. Discussion

4.1. Framing the Regulatory Policy Debate on Fish Farming by the Scottish Government

The process tracing reveals the Scottish Government, after multiple Scottish Parliament questions and input from various Parliamentary committees, accepted the need to review fish farm regulation following the 2017 and 2018 contentious Parliamentary debates on the subject. This review encapsulates and provides valuable triangulation for the process tracing analysis, as well as further context for the process hypotheses. A four year delay occurred before the review was finally set up, but the draft terms of reference for the review were clear. The minister in charge accepted there were social license and environmental elements involved in regulation, but the review’s first objective was to identify those issues that affected the industry’s efficiency and effectiveness and to recommend ways to improve efficiency in the future. The suggested stakeholder list for engagement in the process was heavily weighted towards the fish farming industry [47]. The review was published in 2022 [48] and reflected the earlier approach to regulation and ‘better regulation’ in the country, dating back to the 2000s. This proved to be a key element in framing the debate on fish farming between 2022 and 2025, within government and in the Scottish Parliament. For example, the review, when searched for key terms, contains only one specific reference to food safety, none to hazards, none to working conditions, none to pollution, and none to contamination. This is consistent with the ‘aims’ of the Scottish Better Regulation Group.

The main review included many Scottish Government and fish farming industry arguments against existing regulation, which emerged in the process tracing analysis results. Many aspects of large-scale fish farming currently contested were accepted, perhaps because it was framed specifically “to identify the issues impacting on the efficient and effective operation of the regulatory framework for aquaculture from the perspective of industry, users of the shared marine environment (tourism, wild fisheries), communities and regulators; and make recommendations for further work in relation to improved efficiency and more fundamental institutional reform” [48].

Sustainability was not identified as a specific issue that needed addressing at the outset, although it emerged in both the Scottish Government and Scottish Parliament process tracing, but it is touched on in the review. EmBz was not specifically mentioned, but the review did note the Scottish Government’s program at that time to ‘better protect wildlife and the environment’ and flagged SEPA’s sea lice risk-based consultation exercise. This was in response to the Salmon Interactions Working Group and the need to consult on ‘a spatially adaptive sea lice risk assessment framework for fish farms’ by the end of 2022 and strengthen sea lice controls [48]. The review recommended a ten-year strategy that would include ‘parameters for disease control and other issues such as sea lice within which the industry must operate’ [48].

The limited terms of reference precluded the sort of questions that both the industry and Scottish Government needed to answer about salmon farming from consumer, fish welfare, and environmental perspectives [49]. Unusually, just three references are cited in the report itself (in contrast in places to the Scottish Government and Scottish Parliament material revealed in the process tracing). There is no bibliography, so readers are unable to identify sources for material used in the report. Effectively, opinions that are not therefore evidence-based are provided throughout the document. The Review’s author believed “regulation has evolved and self- regulation is done by industry. Most of that though is now done in partnership with Government and has become known as Government Sponsored Voluntary Regulation. The threat of legislation being put in place behind this is why many industries now have their own rules and regulations that work well and more importantly are policed and monitored” [48].

Others strongly contest this view. Bodies such as the Coastal Communities Network Scotland, for example, met the Reviewer in 2021 and submitted evidence including material on EmBz. Issues about consultation, transparency, sustainability, and operation of the precautionary principle on EmBz use ran through those discussions. The evidence for the assertion that self-regulation by industry works well and is effectively policed and monitored—in itself possibly a contradictory statement—is not provided. Rather, the evidence we have about industry self-regulation, generally in the UK, is that it has failed and continues to fail across the board [14].

Critics have argued for many years that regulatory policy is generally driven in a particular direction and for particular reasons by industry and Government, and does not exist in an ideological and political vacuum. The reason industry works in partnership with Government on self-regulation is that this inevitably means weaker controls and less transparency than would otherwise be the case. The Reviewer openly acknowledged he had ‘some sympathy’ with critics of the precautionary principle from his own knowledge and sympathy for ‘adaptive management’, which fits into ‘better regulation’ and neo-liberal policies. However, nowhere in the report is the precautionary principle properly explained in the context of sustainability. Indeed, the author appears to misunderstand the precautionary principle [25,48] in ways that support both industry and Scottish Government aims, because its ‘harsh application’ would be unsuitable to fish farming. Others consider that the precautionary principle is what is required when such rapid changes occur. Climate change, diminishing biodiversity, pollution, and a lack of sustainability are linked to cases where industry escaped regulation and argued for innovation and rapid development, with catastrophic consequences.

Research has additionally highlighted the asymmetry that can occur between industry-generated negative studies of the adverse effects of chemicals that were accepted and those that produce positive results, where higher burdens of proof were required and rejection more often occurred [49,50,51]. The default position among regulators and governments is to accept the industry negative studies showing no harm, without the same rigorous evaluations applied to positive studies showing harm. Asymmetry in the assessments of some of the EmBz science appears to have occurred, with the Scottish Government effectively moderating and softening the approaches advocated in the 2010s by those who questioned the impacts of EmBz on the environment. The continued existence of various data gaps relating to the effect of veterinary treatment in a range of locations is also problematic. The model used to address these issues, the precautionary principle, was criticized by the Government’s own advisor on regulation, but the evidence for those criticisms is lacking and at no time was the principle fully scrutinized by either its critics or government. At the same time, the process analysis indicates public health and environmental concerns were not prioritized.

One researcher recently commented that Scotland and Norway had developed a scientific consensus on sea lice regulatory controls, facilitating ‘ambitious policy reforms’, whereas in Ireland and Canada, there had been scientific controversy on sea lice impacts, creating conflict between researchers and policy makers [52]. This may be the case for researchers and policy makers, possibly because “Scotland has set comparatively lenient thresholds for on-farm sea lice. Until recently its sea-lice policy was not designed to address interactions between farms and wild fish, but to protect the health of caged salmon” [52]. Although the paper does not focus specifically on EmBz, the author’s conclusion would suggest the dominant better regulation model has worked well for industry with these thresholds. The process analysis conducted here also indicates that, within Scotland, there is still considerable conflict and disagreement about the impact of sea lice controls on the environment between industry, NGOs, and parliamentarians.

4.2. Scottish Government and Scottish Parliamentary Web Sources

These reveal different models of change, ranging from deregulation, through better regulation, to the precautionary principle hypothesized at the beginning of the process tracing analysis. All were drawn on by politicians, regulators, and advisors. This led to some conflict about which models of regulation should be used, in what ways, and at what levels, and about the speed of change that was acceptable in controlling veterinary medicines like EmBz.

The sources reveal the Scottish Government acted both as a mediator between industry, environmental groups, and MSPs in the Scottish Parliament on EmBz, but also as a catalyst of and advocate for particular types of regulation, ‘better regulation’ and de facto deregulation. ‘Independent’ reports were commissioned by the Scottish Government at later stages in the process and their conclusions reflected the ‘better regulation’ model, although consultations with the public moderated aspects of the model and led to stronger controls of EmBz on paper than industry considered were needed. The monitoring, implementation, and enforcement of those standards, however, remains problematic.

By March 2025, the Cabinet Secretary for Rural Affairs, Land Reform and Islands considered Scotland already had ‘a strong regulatory framework’ for salmon fish farming that provided important environmental safeguards. This assessment was contested by environmental groups, because they considered the safeguards too weak, and the industry, who considered regulations too bureaucratic and onerous. The minister did, however, highlight the issue of sea lice treatments and the fact that from February 2024, SEPA began to implement its new Sea Lice Risk Assessment Framework in a ‘new strengthened environmental regime’. This would appear to acknowledge that the previous regulatory system was either inadequate or perceived to be inadequate and shows the impact that the issue raised in FOIs and by MSPs and others in debates from 2012 was having.

It is possible to further triangulate some of the process tracing findings against grey literature provided by investigative journalists, which supports the process tracing’s initial hypotheses and confirms the outcomes. There has been little dispute about most of the facts presented by these journalists, often gathered through FOIs, but their conclusions have been contested by industry and some government ministers.

Independent journalists often produced information not necessarily always disclosed by Governments to the public, either through regulators, the Scottish Government, or the Scottish Parliament. Based on their detailed and factually accurate investigations, they have revealed the ‘better regulation’ model of fish farming and EmBz use is even more powerful than documented in Parliamentary debates and Government reports. They show how the industry was able to influence the decisions of the Government and regulators directly and indirectly.

For example, the Ferret, an independent investigative journalism organization in Scotland, produced no fewer than 27 articles on EmBz between 2017 and 2024 [37], and provided a very different narrative to that presented by both the Scottish Government and the industry. Articles covered environmental pollution generally and how critical reports of the industry did not emerge publicly. Other articles documented evidence that regulators secretly dropped plans to ban EmBz in 2017 due to fish farm industry pressure, revolving ‘job’ doors between the regulator and the salmon producers, industry opposition to new EmBz controls, delays in implementing new safety limits, Scottish Government pressure on regulators not to ban EmBz, impacts of EmBz on Scottish wildlife, industry’s alleged breaching of regulations, and increased use of EmBz over a number of years. In 2025, evidence emerged from the Ferret that the salmon farming industry had stalled EmBz lice controls by bringing multiple appeals against regulatory decisions [37].

These articles by journalists may partially explain the greater government and regulatory disclosures on EmBz since 2000 and possibly the greater if still limited accountability of Government and regulators. From a position of relative confidence in controls over small-scale salmon fish farm impacts, supported by relatively limited research on the environment, fish welfare, and consumer safety issues in the latter half of the 20th Century, a process of growing awareness of potential problems with EmBz emerged (See Table 1 above). The fish farming industry usually contested the concerns.

For the industry, tougher precautionary approaches have been widely criticized and de facto new controls have been resisted in practice [20,21,42,43,44]. In May 2024, the industry’s main body reportedly welcomed the Scottish Parliament’s Rural Affairs and Islands (RAI) Committee decision to follow up on its earlier review of the industry [42,43]. In May, the Salmon Scotland chief executive Tavish Scott reportedly argued the government’s task was to create the conditions for change and growth, not to interfere or hold back business [42,43]. He commented “Companies need the business conditions to succeed, which means real progress on a consenting system which still involves four different regulators–we do not yet have the “one-stop shop” recommended by Professor Russel Griggs” [43].

5. Conclusions

The ‘better regulation’ model, outcomes, and changes proposed to support it were challenged and modified at various points, as the process tracing analysis reveals and FOIs over a period of years have shown. The process of change to ‘better regulation’ to help the fish farming industry was disrupted by some MSPs, environmental groups, and possibly the media, whose FOIs and investigations led to proposals for new systems and frameworks for regulators to monitor and control EmBz. Different regulatory models can sometimes co-exist in various frameworks or chronologically overlap within governments and regulatory agencies advocating and applying them. The system and licensing was then challenged by the fish farming industry, and currently in 2025, those challenges have potentially succeeded in neutralizing regulatory action, and so the process will continue.

The science/evidence base and research, often funded by the fish farming industry, have also at times been perceived by environmental and consumer groups to reflect the priorities of the deregulatory model regarding EmBz. The process tracing of Scottish Parliament activity and Scottish Government responses showed this. There were growing concerns about the potential environmental effects of EmBz and how controls were not being tightened over at least 13 years. These were hampered at times. Firstly, this happened because of a lack of transparency and/or use of confidentiality to block disclosures regarding such research, which generates mistrust in findings. Secondly, there appeared to have been a lack of meaningful engagement with some local communities and environmental groups by researchers.

Further quantitative and qualitative research will provide fuller assessments of the regulation, enforcement efficacy, and effects of various sea lice treatments, including EmBz and its alternatives. Such research should also offer a more complete insight, perhaps through interviews with key players, into the underpinning approaches and ‘behind the scenes’ influences on both policy and practice. Nevertheless, Scottish Government and Scottish Parliament sources publicly available now on the web reveal how policy evolved from an acceptance over many years of the environmental quality standards for EmBz as satisfactory to a commitment to tighten those standards. Effectively, there has been a recognition that over time the ‘better regulation’ model as implemented in the fish farming sector could be challenged and was not necessarily fit for purpose. Avoiding unnecessary duplication of regulatory functions was, however, desirable, but how exactly this would be implemented and achieved has not yet been never properly documented and tested.

For environmental groups and other NGOs, this translated into using the precautionary principle model. From a precautionary principle perspective, the Scottish Government approach to EmBz showed a high degree of flexibility but appeared to lack foresight, limited responses to the burdens of proof required, lacked prompt action, and in terms of the influence of the industry on itself and the regulator, will also have been viewed as lacking fairness and transparency. The Scottish Government undoubtedly responded to both non-industry and industry criticisms of EmBz controls, but outcome evidence shows its policies remained underpinned by the better regulation agenda that it has supported since the 2000s.