This guest blog is authored by Professor James Harrison, Professor of Environmental Law at the University of Edinburgh Law School. Prof. Harrison has previously written guest blogs on ‘the UK as an international fisheries actor’ and ‘Unpacking the legal disputes over Rockall’ and SPICe briefings on UK-EU fisheries negotiations and the UK Fisheries Bill.
As with all guest blogs, what follows are the views of the author, not those of SPICe or the Scottish Parliament.
Introduction
In March 2024, the UK and Scottish Governments closed North Sea Waters to sandeel fishing. The decisions were taken to protect vulnerable seabird populations, which feed on the species, and to support the wider marine environment.
Soon after, the EU launched a formal challenge to the decision due to the economic impact on Member States’ fishing fleets. This was the first dispute to be litigated under the UK-EU Trade and Cooperation Agreement.
This blog examines the outcome of the challenge, what it means for the UK’s autonomy as an independent coastal state, and future UK-EU cooperation.
Background to the Trade and Cooperation Agreement
Following the UK’s exit from the EU at the end of 2020, the UK and the EU have entered a new cooperative relationship across a range of matters, including fisheries management.
Fisheries was one of the critical issues in the Brexit negotiations (see SPICe briefing). A key obligation in the final text of the Trade and Cooperation Agreement requires the UK and EU to:
‘cooperate with a view to ensuring that fishing activities for shared stocks in their waters are environmentally sustainable in the long term and contribute to achieving economic and social benefits, while fully respecting the rights and obligations of independent coastal States as exercised by the Parties’ (article 494(1) – emphasis added).
The express recognition of the rights of independent coastal states was important for the UK, as a key objective of the negotiations was to allow the UK to regulate fishing vessels operating in its waters.
Under Part V of the United Nations Convention on the Law of the Sea (UNCLOS), all coastal states have ‘sovereign rights for the purpose of exploring and exploiting, conservation and managing the natural resources’ of the Exclusive Economic Zone (an area of sea that extends up to 200 nautical miles from the territorial sea baselines of a state, or up to an agreed maritime boundary with neighbouring coastal states).
This includes the right to prescribe and enforce conservation and management measures applicable to all fishing vessels in this area.
Such measures might include:
- specifications on the type of fishing gear or other equipment that must be used by fishing vessels;
- closure of specific areas to fisheries to protect fish stocks or the wider marine environment;Â
- requirements on the information that must be provided to the coastal state by fishing vessels.Â
Before Brexit, the EU held exclusive competence over fisheries regulation in the UK’s Exclusive Economic Zone. This meant that the EU had sole authority to legislate on fisheries matters. The UK could only act in these areas if specifically authorised by the EU or to implement EU laws. Reassuming sole regulatory authority was therefore an important milestone for the UK in regaining its status as an independent coastal state.
The final text of the Trade and Cooperation Agreement expressly acknowledges the ‘regulatory autonomy of the parties’ as one of the principles of the Agreement (article 494(3)(f)). This autonomy is not completely unconstrained, however.
The Trade and Cooperation Agreement imposes important duties on the parties in relation to two key aspects of fisheries cooperation:
- setting total allowable catch (TAC) – the quantity of fish that can be caught for a given fish stock, typically on an annual basis.
- granting access to fishing grounds by vessels of the other party (as discussed in a recent SPICe blog).
The Agreement also places limits on the discretion of the parties to adopt and apply fisheries management measures within their waters. These limitations notably include:
- A duty to base measures on the best available science (article 496(2))
- A requirement to apply the same measures to vessels of the other party as are applied to its own vessels (article 496(2))
- A duty to have regard to the principles set out in the Agreement, including the principle of applying proportionate and non-discriminatory measures for the conservation of marine living resources and the management of fisheries resources (article 496(1))
- An obligation to consult the other party before applying conservation and management measures (article 496(3))
The UK’s compliance with these obligations is what led to the Sandeel arbitration between the UK and the EU, which is the first dispute to be litigated under the Trade and Cooperation Agreement.
The ban on sandeel fishing in UK waters
Sandeels are small, thin fish, which cluster in large shoals around the Scottish coast. They have been described by NatureScot as a ‘corner stone of the Scottish marine ecosystem’ and ‘one of the most important food species for many marine predators including seabirds.’ According to NatureScot, overall seabird numbers in Scotland have fallen by 48% since 1986.
At the same time, they are fished in large numbers by industrial fishing boats, with the catch mostly used for producing fishmeal. In 2024, a total allowable catch of 169,411 tonnes was set for the sandeel fishery in the North Sea, of which more than 95% was allocated to the EU.Â
The UK only receives a small proportion of this TAC. Moreover, the UK government has not distributed its allocation to UK vessels since 2022, citing ‘the benefit of the wider marine ecosystem – such as seabirds and marine mammals’, as the main rationale. Â
A legal challenge to this decision brought in the Scottish courts by one of the affected fishing businesses failed, with the judge finding that ‘in principle it was open to the Secretary of State to take the view on the basis of the scientific and other material before him that prohibiting sandeel fishing by UK vessels would produce environmental benefit.’ Indeed, steps were soon taken to go further and completely ban sandeel fishing in UK waters by all vessels.
Between March 2023 and May 2023, the UK Department for Environment, Food and Rural Affairs ran a consultation on a proposed prohibition of sandeel fishing in English waters of the North Sea.
The Scottish Government also ran a consultation from July 2023 to October 2023 on a similar proposed prohibition of sandeel fishing throughout Scottish waters. Prohibitions were subsequently brought into force in both English waters and Scottish waters on 26 March 2024. Â Given that UK vessels had already been prevented from fishing for sandeel, the main impact of this ban was on EU vessels fishing in UK waters.
The legal challenge and arbitration process
Where a dispute arises between the parties to the Trade and Cooperation Agreement, there is an elaborate dispute settlement procedure available. This ultimately allows a party to take a case to an international arbitral tribunal, composed of independent ‘judges’ appointed by both parties.
The EU initiated this dispute settlement procedure in April 2024 when the EU requested consultations with the UK on the subject of the sandeel fishing prohibition. The parties were not able to resolve their differences through consultations and so the EU proceeded to request the establishment of an arbitral tribunal in October 2024.
The three-person Tribunal was established on 4 November 2024 and the parties made both written and oral presentations to the Tribunal between November 2024 and February 2025. The final ruling of the Tribunal was delivered on 28 April 2025.
The EU made a number of arguments, mostly focussing on two key aspects:
- the scientific basis for the prohibition
- the alleged discriminatory and disproportionate impact of the measures.Â
The ruling on these arguments is summarised below.
Were the measures based upon the best available scientific evidence?
The Tribunal accepted that it was competent to scrutinise the science that was used by the UK, noting that scientific advice must ‘display methodological rigour … situated within a scientific discipline’ and it must be ‘scientifically objective and transparent, in the sense of being open to scrutiny and corroboration’ (para 485).
Whilst the EU pointed to a number of deficiencies in the science used by the UK, particularly the ecosystem modelling, the Tribunal ultimately held that these problems were not of a sufficient magnitude to undermine the overall scientific basis of the measure.
The Tribunal recognised that ‘it is always possible to highlight flaws in ecosystem models’ (para. 558) and they went on to clarify that a breach of the Agreement would only arise if any flaws in the scientific evidence, assessed holistically, would have made a material difference to the results of the assessment (para 507). This was not the case in relation to the sandeel prohibition adopted by either the UK Government or the Scottish Ministers.
Were the measures discriminatory or disproportionate?
The Tribunal noted in this context that the Agreement requires parties to ‘have regard to’ these principles, and this obligation demands that the decision-maker engage with the principles in coming to a decision, even if ‘such considerations may, ultimately, be unavailing’ (para 605).
This interpretation means that the Tribunal was required to carry out a review of whether the various factors bearing on the proportionality and discriminatory nature of a measure were considered and whether these considerations were applied in the actual weighing and balancing in the final decision.
However, it was not for the Tribunal to step into the shoes of the decision-maker and determine the precise weight that should be accorded to all of the relevant factors, as this would impinge upon the regulatory autonomy of the parties.
Ultimately, it was a failure of the UK Secretary of State to expressly address all of the relevant factors in their decision-making record which led the Tribunal to find that the prohibition of sandeel fishing in English waters of the North Sea was a breach of the Agreement.
In particular, the Tribunal identified that there had been no explicit recognition in the decision-making process of the access rights of the EU to fish in UK waters until the end of the transition period. According to the Tribunal, this was ‘a factor of such import that it had to be taken into account in the weighing and balancing process’ (para 678).
However, this finding only related to the decision on sandeel fishing in English waters of the North Sea. In contrast, the Scottish decision was found to have taken into account the impact on the access rights of the EU and this decision was therefore not in breach of the Agreement.
Reaction to the decision
It is no surprise that the Scottish Government described the result as ‘an extremely positive ruling.’ The UK Government reaction to the ruling was also positive noting that there was only one finding against the UK. Â
The UK Government committed to ‘undertake a process in good faith to bring the UK into compliance’ whilst also noting that ‘there is no legal obligation for the UK to reverse the closures while the compliance process takes place, and the report does not indicate that compliance must require reversing the closures.’
The European Commission also welcomed the ruling and it said that it would ‘continue to work with the UK to ensure the long-term sustainability of fisheries and to ensure a mutually beneficial relationship.’
Conclusion
This is the first time that the dispute settlement procedure under the Trade and Cooperation Agreement has been invoked and the first time that the fisheries provisions of the Agreement have been judicially interpreted. The case therefore has important consequences for fisheries cooperation between the UK and the EU in the long-term.
On the whole, the ruling reinforces the flexibility that is open to coastal states to take conservation and management measures, provided that they carry out a clear and reasoned decision-making process. These interpretations will have wider implications for the adoption of future conservation and management measures by both parties.
Addressing this point before the Environment, Food and Rural Affairs Select Committee of the UK Parliament, the Secretary of State for the Environment, Food and Rural Affairs noted that the outcome of the arbitration was largely in favour of regulatory autonomy and the ruling would allow the UK fisheries administrations to ‘look at other species as well where we think there is action to be taken.’
Professor James Harrison, University of Edinburgh
Title image: Steve Garvie from Dunfermline, Fife, Scotland, CC BY-SA 2.0 https://creativecommons.org/licenses/by-sa/2.0, via Wikimedia Commons