Publication - Advice and guidance

Aquaculture: code of practice

Published: 21 Sep 2021
Marine Scotland Directorate
Part of:
Marine and fisheries

Sets out standards expected from Aquaculture Production Businesses in Scotland (“APBs”) in order to provide for the containment of fish on fish farms and to prevent their escape in relation to marine mammal interactions.

Aquaculture: code of practice
Section 1: Introduction

Section 1: Introduction

Using this Code

1. Section 7 of the Aquaculture and Fisheries (Scotland) Act 2007 (“2007 Act”) empowers the Scottish Ministers to approve a code of practice, in whole or in part, in order to give practical guidance to fish farmers, promoting desirable practices with respect to the containment of fish on fish farms and the prevention of escapes by farmed fish. Once approved, such a code of practice is subject to the monitoring and enforcement powers as provided in the 2007 Act.

2. This Code of Practice (the “Code”) sets out standards expected from Aquaculture Production Businesses in Scotland (“APBs”) in order to provide for the containment of fish on fish farms and to prevent their escape. This Code focusses upon addressing the risks concerning containment and escape of farmed fish arising from marine mammal interactions at fish farms (where the term “marine mammals” includes both seals and cetaceans). Appropriate measures to ensure containment and prevent escape of farmed fish are also referred to within this Code as “non-lethal measures”.

3. This Code provides a combination of guidance for APBs, together with mandatory standards with which APBs must comply. Section 2 of the Code addresses containment measures, while Section 3 focusses upon reporting requirements. Each of these sections has a sub-section that provides guidance on these matters, and a separate sub-section containing the mandatory standards for APBs.

4. In this Code, the term “you” means an APB authorised to operate under the Aquatic Animal Health (Scotland) Regulations 2009.

5. If you have any questions concerning this Code please contact Marine Scotland at email:; post: Marine Scotland, Mailpoint 11, 1B South, Victoria Quay, Edinburgh EH6 6QQ; telephone: 0300 244 4000.

Background to the Code

6. The aquaculture sector is an essential component of the Scottish economy, contributing to sustainable economic growth in rural and coastal communities. In 2018, Scottish aquaculture and its wider supply chain contributed £880 million GVA to the Scottish economy and supported over 11,700 jobs.[1]

7. In addition, the seas around Scotland are internationally important as a source of marine biodiversity, supporting a wealth of wildlife including twenty-two species of marine mammals, comprising cetaceans (whales, dolphins and porpoises) and two species of pinnipeds (grey seals and harbour seals).

8. Both grey seals and harbour seals (also known as common seals) are amongst the most widely found marine mammals in Scottish waters. Seals may be attracted to fish farms, especially in circumstances where they learn to associate the farmed fish as a potential source of food. This can result in damage to nets and other aquaculture equipment which can in turn jeopardise the containment of farmed fish and risk their escape. Seals may be one of the causes of mortality as well as stress and welfare issues in farmed fish.

9. The aim of this Code is to address the impact of marine mammal interactions upon containment and escape of fish at fish farms. The practical measures identified within this Code are focussed upon addressing the risks concerning containment and escape of farmed fish arising from marine mammal interactions, particularly those involving seals. The potential impact of marine mammals upon fish farms should be mitigated through the adoption of appropriate containment measures, while ensuring that these measures are not harmful to marine mammals. Appropriate containment measures are likely to vary between fish farms due to a range of factors including the presence of marine mammals and the behaviour of individual animals. APBs should adopt those measures that they identify as appropriate for their particular circumstances and that are in accordance with the mandatory standards contained in this Code. Appropriate containment measures include non-lethal measures that deter seals without causing harm to seals or other marine mammals.

10. The measures contained within this Code reflect existing good practice in the aquaculture industry,[2] including the use of tensioned or false-bottomed nets. Certain new materials such as stainless-steel core high-density polyethylene (“HDPE”) also provide mitigation against marine mammal interactions. Additional well-established containment measures in relation to marine mammal interactions include daily removal of fish mortalities (e.g., by daily emptying of any dead fish baskets) and use of seal blinds to deter access to fish mortalities settled within the fish farm pen. Any proposal to use acoustic deterrent devices (“ADDs”) must be in compliance with an APB’s relevant legal obligations, including those under the Conservation (Natural Habitats, &c.) Regulations 1994, to ensure that any impacts on the marine environment are properly managed and safeguarded for future generations.

11. The Code also introduces a system of monitoring and reporting in order to document the use of these containment measures in a systematic way throughout Scotland’s aquaculture industry and to log any killing or injury of marine mammals (known as “bycatch”) associated with fish farms.

To whom does the Code apply?

12. The Code applies to every APB operating a fish farm in Scotland’s marine environment. Whilst likely to be an extremely rare event, the Code would also apply to any interactions with marine mammals occurring at freshwater fish farms (note that the reporting requirement in relation to nil returns specified in Section 3.2 does not apply to freshwater fish farms).

What are the standards of practice provided by the Code?

13. This Code provides a combination of guidance and mandatory standards for APBs. Section 2 of the Code addresses containment measures, while Section 3 focusses upon reporting requirements. These sections provide guidance on these matters (in Sections 2.1 and 3.1), together with mandatory standards for APBs (in Sections 2.2 and 3.2).

14. Adherence to the Code requires APBs to comply with the mandatory standards which are set out within Sections 2.2 and 3.2 in relation to:

  • The use of appropriate containment measures at fish farms (as described in Section 2.2);
  • The reporting of the use of containment measures at fish farms on an annual basis, including nil returns (as described in Section 3.2);
  • The reporting of any killing or injury of marine mammals in the form of bycatch at fish farms within 48 hours of the APB becoming aware of the incident (as described in Section 3.2).

What are the consequences of an APB’s non-compliance with the Code?

15. The mandatory standards specified within Sections 2.2 and 3.2 of the Code are subject to monitoring and enforcement processes as provided in the 2007 Act:

  • Monitoring: the 2007 Act requires the Scottish Ministers to monitor compliance with the Code (once it is approved by them) (section 8(1)).
  • Service of notice: if an APB is not complying with the Code (or is likely not to comply with the Code) in a material regard, the Scottish Ministers may serve a notice on that APB requiring (a) the execution of such works, and (b) the taking of such other steps, as the Scottish Ministers consider necessary for securing compliance with the Code (section 8(2)-(4)).
  • Contravention of notice: a person who contravenes a notice, without reasonable excuse, is guilty of a criminal offence and is liable on summary conviction to a fine not exceeding level 4 on the standard scale, which currently equates to a maximum fine of £2,500 (section 6(9)-(10) as applied by section 8(5)).
  • Appeal of notice: there is a right of appeal against a notice by summary application to the sheriff (section 6(7)-(8) as applied by section 8(5)).

How does other legislation relate to the Code?

16. As well as complying with this Code, APBs must also ensure that they comply with all other legal obligations which apply to them, including in relation to marine mammal protection and farmed fish welfare.

17. For example, when adopting appropriate measures in relation to marine mammals under this Code, in order to contain and prevent the escape of fish on fish farms, APBs must adhere to all the other duties placed upon them under the 2007 Act and all applicable regulations. Moreover, further responsibilities are placed upon APBs under the Animal Health and Welfare (Scotland) Act 2006 to provide for the welfare of fish on fish farms. The content of this Code does not change these responsibilities.

18. In addition, APBs must continue to comply with all site-based and species-based protection measures applicable to marine mammals (cetaceans and seals). For example, the Conservation (Natural Habitats, &c.) Regulations 1994 (the “Habitats Regulations”) afford a high level of strict protection for all cetaceans by prohibiting their deliberate or reckless capture, injury, disturbance and killing,[3] while seals are protected through Part 6 of the Marine (Scotland) Act 2010 from intentional or reckless injury, taking and killing. There are only limited exceptions to these offences including for the purpose of alleviating suffering and under strict licensing provisions,[4] and there are significant penalties associated with non-compliance in line with the most serious wildlife offences. The content of this Code does not change these responsibilities.

19. For fuller details on the legal responsibilities of APBs, you should refer to the current legislation. You are advised to obtain independent legal advice in relation to your rights and responsibilities under the existing legal and regulatory framework for APBs.

Will there be updates and changes to the Code?

20. Best practice is likely to change as both technology and knowledge improve. Any new measures or other changes to best practice should be reflected in the requirements of the Code. Any future updates and changes to the Code would be subject to the processes within section 7 of the 2007 Act, which provides that the Scottish Ministers may approve a modification of an approved code of practice (section 7(3)). Any such modifications would be subject to the same process of public consultation that informed the development of the Code (section 7(4)).