FREE EXCERPT from ‘A Practical Guide to Marine Mammal Law in the UK’ by Helen Mitcheson

07/10/2025

INTRODUCTION

The territorial[1] and offshore[2] waters of the United Kingdom hosts over twenty known species of marine mammals, including cetaceans (whales, dolphins and porpoises) and pinnipeds (seals and walrus[3]). Among the most encountered cetaceans are the harbour porpoise (Phocoena Phocoena), bottlenose dolphin (Tursiops truncatus), common dolphin (Delphinus delphis), white-beaked dolphin (Lagenorhynchus albirostris), Risso’s dolphin (Grampus griseus), orca (Orcinus orca) and minke whale (Balaenoptera acutorostrata). Larger migratory species such as humpback whales (Megaptera novaeangliae), fin whales (Balaenoptera physalus), sperm whales (Physeter macrocephalus) and pilot whales (Globicephala spp) are increasingly recorded in UK waters also. These species vary in size, behaviour and sensitivity to threats, which include bycatch and entanglement, underwater noise, recreational pressures, vessel strikes, pollution, prey depletion, habitat degradation and the escalating impacts of climate change.

Some populations are year-round residents, such as coastal groups of bottlenose dolphins and harbour porpoise, while others are transient or seasonal visitors. Additionally, recent years have seen increasing reports of vagrant species, including Arctic species like the beluga whale (Delphinapterus leucas) – notably spotted in the River Thames in 2018 and in Shetland in 2024. Deep-diving beaked whale species have also been identified, sadly as a result of stranding along the UK’s coastline.

The UK is also home to two resident pinniped species: the grey seal (Halichoerus grypus) and the harbour (or common) seal (Phoca vitulina). Occasional sightings of vagrant pinnipeds – such as walruses (Odobenus rosmarus) and ringed seals (Pusa hispida) – have also been recently recorded.

Pinnipeds are both terrestrial and marine in behaviour, using coastal haul-out sites for critical life stages such as resting, breeding and moulting. These haul-out sites vary in accessibility and environmental exposure, ranging from open beaches to secluded coves and rocky outcrops. With the growth of coastal recreation and tourism, anthropogenic disturbance to pinnipeds – both on land and in water – is of increasing concern. Pinnipeds also face additional pressures from climate change, including increased coastal erosion and more frequent and intense storms.

Over the years, a number of legal mechanisms have developed to offer protection to marine mammals in the UK, including through both wildlife and fisheries legislation. However, there is no single legal instrument in the UK that is specifically designed for marine mammals.

Long before the development of modern conservation law, cetaceans were recognised in British law as animals of significant royal interest. Under a long-standing prerogative doctrine, these species were classified as ‘royal fish’ – a designation which means that when found stranded or caught in UK waters, they become the property of the Crown.[4] The doctrine of royal fish continues to hold symbolic and procedural significance within the UK’s legal landscape, reflecting its enduring presence.[5]

The legal framework for marine mammals in the UK has therefore emerged from a complex framework of domestic statutes, assimilated EU law and devolved governance structures.[6] This patchwork of regulatory regimes varies considerably in scope, application and enforceability, creating disparities in implementation. For instance, a species’ legal status may differ based on its habitat, migratory behaviour or interactions with regulated activities such as commercial fishing, offshore energy development or marine tourism.

Navigating this intricate legal landscape presents significant challenges. Practitioners, policymakers and advocates often grapple with the task of interpreting how overlapping laws apply to specific circumstances. The reliance on general environmental or fisheries legislation and associated guidance can hamper efforts to achieve coherent legal scrutiny, effective enforcement and informed public engagement that is appropriate to these unique species and their marine environment. This inevitably undermines the robustness of legal protections afforded to marine mammals, leaving them vulnerable to both emerging and persistent threats.

Recognising this critical gap, this book seeks to provide a structured, practical legal resource focussed specifically on marine mammals within UK law. It consolidates and clarifies the relevant legal frameworks, clearly explaining their connections to offences, protected areas, assessment, disturbance, fisheries interactions, captivity, capture and welfare. Each chapter anchors its analysis in current statutory provisions while highlighting areas of legal ambiguity and potential reform.

By offering a comprehensive examination of the legal landscape, this book aims to enhance understanding and provide a unique resource for those seeking to reconcile marine mammals and law.

 

 

CHAPTER ONE – UNDERSTANDING OFFENCES AGAINST MARINE MAMMALS: NAVIGATING A FRAGMENTED LEGAL FRAMEWORK


INTRODUCTION

Marine mammal protections in the UK stem from international, European and domestic law.

All cetacean species found in UK waters are European protected species, being listed in Annex IV(a) of the EU Habitats Directive.[7] In addition, in England, Wales and Scotland, some cetaceans are nationally protected species, being listed in Schedule 5 of the Wildlife and Countryside Act 1981[8] (as amended) (WCA 1981). This dual status ostensibly offers strict protection against deliberate or reckless acts such as killing, injury or disturbance.

By contrast, pinniped protections are far less comprehensive. Neither the grey seal nor the harbour seal is listed in Annex IV(a) of the Habitats Directive and therefore neither species qualifies as a European protected species. The grey and harbour seal are also not included in Schedule 5 of the WCA 1981 in England, Wales and Scotland, meaning they lack full national protection under that instrument. Notably, the walrus is the only pinniped listed in Schedule 5 of the WCA 1981. In Northern Ireland however, pinnipeds are protected under the Wildlife (Northern Ireland) Order 1985 (as amended).[9]

Nevertheless, grey and harbour seals benefit from partial protections under other legislative instruments in England, Wales and Scotland, including the Conservation of Seals Act 1970[10] (as amended) and the Marine (Scotland) Act 2010.[11] Seals may also be protected when they form part of the notified features of Sites of Special Scientific Interest (SSSIs.[12]

The following statutes establish specific offences related to marine mammals in UK waters:

  • The Conservation of Habitats and Species Regulations 2017,[13] as amended (applicable in England and Wales, including the adjacent territorial sea, up to 12 nautical miles (nm)[14] from the coastal baseline);[15]
  • The Conservation of Offshore Marine Habitats and Species Regulations 2017,[16] as amended (applicable beyond 12nm throughout the UK offshore marine area, including Scottish and Northern Irish offshore waters);[17]
  • The Conservation (Natural Habitats, &c.) Regulations 1994,[18] as amended (applicable up to 12nm in Scottish inshore waters);[19]
  • The Wildlife and Countryside Act 1981, as amended (applicable up to 12nm in England, Wales and Scotland);[20]
  • The Conservation of Seals Act 1970, as amended (applicable up to 12nm in England and Wales);[21]
  • The Marine (Scotland) Act 2010 (applicable up to 12 nm in Scotland);[22]
  • The Wildlife (Northern Ireland) Order 1985, as amended (applicable up to 12nm in Northern Ireland);[23] and
  • The Conservation (Natural Habitats, etc) Regulations (Northern Ireland) 1995, as amended (applicable up to 12nm in Northern Ireland).[24]

Each of these legislative instruments contains varying definitions and thresholds for activities which constitute an offence – particularly regarding ‘disturbance’[25] – and apply differently across UK jurisdictions due to devolution and legal divergence following the UK’s withdrawal from the European Union (Brexit). These issues collectively create a fragmented and often incoherent legal landscape, as highlighted by the Environment, Food and Rural Affairs Committee in its 2023 report on marine mammal protection[26] (which is discussed in Chapter 9).

This chapter provides an overview of these legal frameworks that govern offences against marine mammals in the UK, focussing on the different regimes for cetacean and pinniped species.


CETACEANS

European Protected Species

The Habitats Directive requires Member States to ensure the conservation of natural habitats and of wild species of fauna and flora of European Community Interest, aiming to maintain or restore them to ‘favourable conservation status’.[27] In doing so, the Habitats Directive obliges Member States to enforce a system of strict protection for species listed in Annex IV(a), which includes all cetaceans.[28]

Despite Brexit, the Habitats Directive remains embedded in domestic law[29] through:[30]

  • The Conservation of Habitats and Species Regulations 2017, as amended;
  • The Conservation of Offshore Marine Habitats and Species Regulations 2017, as amended;
  • The Conservation (Natural Habitats, &c.) Regulations 1994, as amended; and
  • The Conservation (Natural Habitats, etc) Regulations (Northern Ireland) 1995, as amended.

Where discussed together, these implementing Regulations are referred to as the ‘various Habitats Regulations’ throughout this book. Where discussed individually, unless specified, reference is always to the most recent ‘amended’ version of the respective Regulations.

‘Strict Protection’

The key provision underpinning the legal protection of cetaceans is Article 12 of the Habitats Directive. Article 12 requires Member States to take requisite measures to establish a system of strict protection for Annex IV(a) species in their natural range, prohibiting, as applicable to marine mammals:

  • all forms of deliberate capture or killing of specimens of these species in the wild;[31]
  • deliberate disturbance of these species, particularly during the period of breeding, rearing, hibernation and migration;[32] and
  • deterioration or destruction of breeding sites or resting places.[33]

In addition, Member States must establish a system to monitor the incidental capture and killing of Annex IV(a) species, and in light of the information gathered, undertake further research or conservation measures as required to ensure that incidental capture and killing does not have a significant negative impact on the species concerned.[34] This provision is discussed further in Chapter 7 on bycatch.

Offences under the various Habitats Regulations

The various Habitats Regulations implement the Habitats Directive with jurisdictional differences across England, Wales, Scotland and Northern Ireland.

England and Wales

Under the Conservation of Habitats and Species Regulations 2017, it is an offence to deliberately capture, injure, kill[35] or disturb[36] wild animals of any species listed in Annex IV(a) of the Habitats Directive. Importantly, the 2017 Regulations provide a definition of ‘disturbance of animals’ (see Chapter 6 for more detail). This definition includes, in particular, any disturbance which is likely to impair their ability to survive, to breed or reproduce, to rear or nurture their young, to hibernate or migrate or to affect significantly the local distribution or abundance of the species to which they belong.[37]

The Conservation of Offshore Marine Habitats and Species Regulations 2017 broadly mirrors the suite of offences and the definition of ‘disturbance’, ensuring continuity of protection for cetaceans throughout UK offshore waters.[38]

Table 1 provides a summary of the offences under regulation 43 of the Conservation of Habitats and Species Regulations 2017 as applicable to marine mammals…

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[1]   The territorial sea of the UK extends up to 12 nautical miles (nm) from the baseline, as defined in section 1 of the Territorial Sea Act 1987. The baseline is typically the low water mark around the coast, and the UK baseline is delineated in the Territorial Waters Order in Council 1964 (as amended). Nautical miles are used to measure the distance travelled through water. A nautical mile is slightly longer than a mile on land, equalling 1,852 metres. The nautical mile is based on the Earth’s longitude and latitude coordinates, with one nm equalling one minute of latitude.

[2]   For the purposes of this book, offshore waters refer to those within the Exclusive Economic Zone (EEZ). The EEZ extends from the outer limit of the territorial sea to 200 nautical miles from the baseline or to the median line with another coastal state’s EEZ. The UK EEZ is outlined in the Exclusive Economic Zone Order 2013 (SI 3163/2013).

[3]   Sea lions are also pinnipeds, but since they are not found in the wild in the UK, they are not discussed in this book.

[4]   The doctrine of royal fish originates in medieval English common law. One of the earliest references appears in Henry de Bracton’s 13th century treatise De Legibus et Consuetudinibus Angliae (“On the Laws and Customs of England”), which states that the King is entitled to whales and sturgeon taken in the sea or elsewhere in the realm. In the 18th century, William Blackstone’s Commentaries on the Laws of England affirmed this principle, noting that “A tenth branch of the king’s ordinary revenue, said to be grounded on the consideration of his guarding and protecting the seas from pirates and robbers, is the right to royal fish, which are whale and sturgeon: and these, when either thrown ashore, or caught near the coasts, are the property of the king, on account of their superior excellence. Indeed our ancestors seem to have entertained a very high notion of the importance of this right; it being the prerogative of the kings of Denmark and the dukes of Normandy; and from one of these it was probably derived to our princes. It is expressly claimed and allowed in the statute de praerogativa regis [of the king’s prerogative]: and the most ancient treatises of law now extant make mention of it.” (William Blackstone, Commentaries on the Laws of England, Vol I (Oxford, 1765)). Although originally developed in England, the doctrine applies across the UK today, albeit with jurisdictional distinctions. In England, Wales and Northern Ireland, the rights to royal fish are exercised on behalf of the Crown by the Receiver of the Wreck, an official of the Maritime and Coastguard Agency – anyone finding a cetacean stranded along the coastline is required to report it to this authority. In Scotland, ownership of royal fish is reserved to the Crown and managed by the Crown Estate Scotland, though in practice any such strandings are handled by the Scottish Marine Animal Stranding Scheme (SMASS).

[5]   While the Crown may retain ownership of stranded cetaceans under the doctrine, in practice, the actual process of accessing, sampling or studying dead cetaceans is governed by wildlife laws such as the Wildlife and Countryside Act 1981 and the Conservation of Habitats and Species Regulations 2017 (and the various Habitats Regulations in Scotland and Northern Ireland). In England and Wales, for example, the UK Cetacean Strandings Investigation Programme (CSIP) is authorised by Defra to undertake post-mortem examinations on dead stranded cetaceans. Their work is facilitated by the Receiver of the Wreck, who acts on behalf of the Crown.

[6]   The UK is made up of four nations – England, Wales, Scotland and Northern Ireland – with a system of devolved government that delegate varying degrees of legislative power to each. Devolution began in earnest with the passing of the Scotland Act 1998, the Government of Wales Act 1998 (and later 2006) and the Northern Ireland Act 1998, which established legislatures and governments in each of those nations. Under this framework, much environmental protection, nature conservation and wildlife law is devolved to the Scottish Parliament, the Senedd Cymru (Welsh Parliament) and the Northern Ireland Assembly. Consequently, each jurisdiction has the authority to develop its own environmental and conservation legislation. This has led to divergence in legal approaches across the UK. For example, the Conservation of Habitats and Species Regulations 2017 (as amended) in England and Wales, the Conservation (Natural Habitats, &c.) Regulations 1994 (as amended) in Scotland and the Conservation (Natural Habitats, etc.) Regulations (Northern Ireland) 1995 (as amended). Similarly, while the Wildlife and Countryside Act 1981 applies across Great Britain (England, Wales and Scotland), its provisions have been amended and interpreted differently in England, Wales and Scotland, resulting in variations in species protection and enforcement provisions. Understanding this devolution is essential to navigating the legal frameworks governing marine mammals in the UK.

[7]   Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora.

[8]   Wildlife and Countryside Act 1981, c. 69.

[9]   The Wildlife (Northern Ireland) Order 1985, No. 171 (N.I.2).

[10]  Conservation of Seals Act 1970, c. 30.

[11]  Marine (Scotland) Act 2010, asp. 5.

[12]  WCA 1981, section 28P.

[13]  The Conservation of Habitats and Species Regulations 2017, SI 2017/1012.

[14]  A nautical mile equals 1,852 metres.

[15]  The Conservation of Habitats and Species Regulations 2017 also extends and applies to Scotland and Northern Ireland (including the adjacent territorial sea to a limited degree), as regards reserved and excepted matters respectively. This is set out in regulation 2 of the Conservation of Habitats and Species Regulations 2017.

[16]  The Conservation of Offshore Marine Habitats and Species Regulations 2017, SI 2017/1013.

[17]  The Conservation of Offshore Marine Habitats and Species Regulations 2017 apply to the UK’s offshore marine area, which means any part of the seabed and subsoil situated in any area designated under section 1(7) of the Continental Shelf Act 1964, and any part of the waters within British fishery limits (except the internal waters of, and the territorial sea adjacent to, the UK, the Channel Islands and the Isle of Man). This is broadly, beyond 12 nm from the coastal baseline and out to 200nm (Regulation 2(1), and Explanatory Memorandum to these Regulations, paragraphs 4.1 and 5),

[18]  The Conservation (Natural Habitats, &c.) Regulations 1994, SSI 1994/2716.

[19]  Referred to as the “Scottish marine area” which is defined as “the area of sea within the seaward limits of the territorial sea of the United Kingdom adjacent to Scotland” (regulation 2(1) of The Conservation (Natural Habitats, &c.) Regulations 1994).

[20]  The provisions of Part I of the WCA 1981 (which is relevant to Chapter 1 of this book) extends to the territorial waters adjacent to Great Britain, and for the purposes of Part 1, any part of Great Britain which is bounded by territorial waters shall be taken to include the territorial waters adjacent to that part (section 27(5) WCA 1981).

[21]  Section 17(2) and (3) of the Conservation of Seals Act 1970 state as follows: “(2) Nothing done outside the seaward limits of the territorial waters adjacent to Great Britain shall constitute an offence under this Act. (3) This Act shall not extend to Northern Ireland.” The Conservation of Seals Act 1970 has been repealed in Scotland by virtue of section 130 of the Marine (Scotland) Act 2010.

[22]  The Marine (Scotland) Act 2010 applies to the “Scottish marine area”, which is defined as the area of sea within the seaward limits of the territorial sea of the UK adjacent to Scotland and includes the bed and subsoil of the sea within that area (section 1(1) of the Marine (Scotland) Act 2010).

[23]  Article 2(5) of The Wildlife (Northern Ireland) Order 1985.

[24]  The Conservation (Natural Habitats, etc.) Regulations (Northern Ireland) 1995, SR 1995/380, regulation 2(4). Please note that only the original version (as it was originally made) is available on gov.uk. In order to view the amendments, please visit Westlaw.

[25]  Disturbance is discussed in further detail in Chapter 6.

[26]  House of Commons Environment, Food and Rural Affairs Committee, Protecting Marine Mammals in the UK and Abroad, Sixth Report of Session 2022-23, HC 697, Published on 28 June 2023 by authority of the House of Commons.

[27]  The concept of favourable conservation status is fundamental to the Habitats Directive and underpins the objectives of both site-based and wider species protection measures. Article 1 of the Habitats Directive defines “conservation” as a series of measures required to maintain or restore natural habitats and species at a favourable status. Article 1(e) states that the conservation status of a natural habitat means the sum of the influences acting on a natural habitat and its typical species that may affect its long-term natural distribution, structure and functions as well as the long-term survival of its typical species; and that the conservation status of a natural habitat will be taken as ‘favourable’ when: its natural range and areas it covers within that range are stable or increasing; and the specific structure and functions which are necessary for its long-term maintenance exist and are likely to continue to exist for the foreseeable future; and the conservation status of its typical species is favourable, as defined in Article 1(i). Article 1(i) states that the conservation status of a species means the sum of the influences acting on the species concerned that may affect the long-term distribution and abundance of its populations within the territory, and that the conservation status will be taken as ‘favourable’ when: population dynamics data on the species concerned indicate that it is maintaining itself on a long-term basis as a viable component of its natural habitats; and the natural range of the species is neither being reduced nor is likely to be reduced for the foreseeable future; and there is, and will probably continue to be, a sufficiently large habitat to maintain its populations on a long-term basis.

[28]  The Mediterranean Monk Seal (Monachus monachus) is the only pinniped species listed in Annex IV(a) of the Habitats Directive. This species has never been recorded in UK waters. Accordingly, it is not discussed in this book.

[29]  And it will remain this way until the Government decides to reform it.

[30]  These regulations had to be updated to ensure that they continued to operate effectively following Brexit. Most of these changes involved transferring functions from the European Commission to the appropriate authorities, and all other processes or terms in the respective regulations currently remain unchanged and the existing guidance is still relevant.

[31]  Habitats Directive, Article 12(1)(a).

[32]  Habitats Directive, Article 12(1)(b).

[33]  Habitats Directive, Article 12(1)(d).

[34]  Habitats Directive, Article 12(4).

[35]  The Conservation of Habitats and Species Regulations 2017, regulation 43(1)(a).

[36]  The Conservation of Habitats and Species Regulations 2017, regulation 43(1)(b).

[37]  The Conservation of Habitats and Species Regulations 2017, regulation 43(2).

[38]  The Conservation of Offshore Marine Habitats and Species Regulations 2017, regulations 45(1) and (2) apply in the ‘offshore marine area’ of the UK, as per regulation 39(1).