Consultation outcome

Methodology for assessing navigation safety risk of aquaculture sites (MGN 687) - Consultation report

Updated 10 July 2026

Introduction

The consultation in June 2023 sought to gather opinions on a new Marine Guidance Note (MGN), MGN 687 (M&F), which aims to set out the methodology to be used for assessing marine navigation safety and emergency response risks from fin/shellfish farms and seaweed/algal farm projects in UK waters. It also provides guidance to marine licence applicants on the type and quality of information that the Maritime and Coastguard Agency (MCA) expects applicants to include within a proportionate Navigation Risk Assessment (NRA). 

The need for this guidance arises from the growing number of fin/shellfish and seaweed/algal farm developments in UK coastal waters and the request from industry and marine regulators for supplementary guidance. Unlike Offshore Renewable Energy Installations (OREIs), for which dedicated NRA guidance already exists under Marine Guidance Note (MGN) 654 (M+F), no equivalent structured framework exists specifically for these farm sites.

Fin/shellfish farm and seaweed/algal farm sites present the following distinct navigational challenges:

• they sit low in the water
• they are often located in sheltered inshore areas heavily used by recreational craft
• they pose entanglement risks from ropes and lines that are different in character from the risks associated with offshore renewables

The Maritime and Coastguard Agency (MCA) is a statutory consulate and/or primary adviser to Marine Licensing regulators across the UK. This guidance has been developed to ensure that navigation risk is assessed comprehensively, proportionately and consistently as part of the marine licence application process for all types of fin/shellfish and seaweed/algal farms. 

The MCA is grateful to all those who took the time to respond to the consultation and apologises for the delay is publishing this report. This report summarises the feedback received and sets out the MCA’s response to the points raised, together with the next steps the MCA intends to take. 

For the purposes of readability, the development of fin/shellfish farms and seaweed/algal farms shall be referred to as ‘aquaculture’ in this report. ‘Aquaculture’ should be read to include only fin/shellfish farms and seaweed/algal farms for the purpose of this report.

Consultation

Consultation process

This is the first consultation for the introduction of this MGN, which was sent out to a total of 64 consultees on 28 June 2023. The consultation was also published on our website for comment by interested parties, with the response period open until 28 August 2023. In this time, the MCA received 20 responses to the consultation form, which represents a 31.3% response rate. Direct emails were also received by a further two individuals, which although not included in this consultation report, were fully considered and feedback has been incorporated into the revised version of the MGN. 

The consultees to whom the MGN was sent represent a broad range of stakeholders from across the industry who have an interest in navigation safety and aquaculture. Those consulted include aquaculture developers, fishing industry representatives, recreational sailing bodies, government departments, marine licensing regulators, the General Lighthouse Authorities (GLAs), maritime consultancies and professional organisations.

Respondents

Responses were received from the following:

• ABPmer
• CaryMor Wales
• Channelled Atlantic
• Cooke Aquaculture Scotland
• DAERA MFD Marine Licensing
• Defra Marine Licensing
• Irish Lights
• Marine Directorate
• Nash Maritime
• National Federation of Fishermen’s Organisations (NFFO)
• Natural Resource Wales
• Royal Yachting Association (RYA)
• RYA Scotland
• Salmon Scotland
• Shetland Fishermen’s Association
• The Law Society of Scotland
• UK Hydrographic Office (UKHO)

Breakdown by sector

A breakdown of the respondents by sector has been demonstrated below.

Sector	Number of respondents	% of responses
Government agency / department	8	40%
Aquaculture developer (inc. trade body)	4	20%
Recreational sailors / users	2	10%
Fishing industry	2	10%
Maritime consultancy	2	10%
Professional body	1	5%
Industry body	1	5%
Total	20	100%

Breakdown by organisation size

Organisation size	Number of respondents	% of responses
Large business / Government department (More than 250 staff or Government department)	10	50%
Medium business (50 to 250 staff)	2	10%
Small business (10 to 49 staff)	2	10%
Micro business (up to 9 staff)	1	5%
Not specified / membership organisation	5	25%
Total	20	100%

Key findings

This section provides an overview of the findings from the consultation period, drawing on the data collected from all nine questions. Further analysis and the MCA’s responses are laid out in Section 4.

Overall response to the MGN

The consultation received a range of constructive responses which highlighted various areas within the MGN for consideration. Most consultees welcomed this MGN, agreeing with the need for guidance on NRA development and emergency response arrangements for aquaculture sites as part of the marine licensing process. 

However, numerous points were raised from across the sectors concerning the MGN’s relation to the OREI background. Many commented that these risks are not transferable to the aquaculture industry, where both the offshore elements and financial backing arrangements are different. 

A significant division existed between aquaculture industry respondents (who were concerned primarily about regulatory burden and duplication) and non-industry respondents such as recreational users and fishing organisations (who considered the requirements insufficiently rigorous, particularly regarding through-life site maintenance).

Headline statistics

Question	Yes	No	No response
1. Is the document fit for purpose?	11	7	2
2. Does it provide everything needed to complete the NRA?	10	8	2
3. Is there any aspect not fully addressed?	13	5	2
4. Does it allow a proportionate approach?	8	10	2
5. Are there aspects which cause concern for your industry?	12	6	2
6. Are the example templates clear and useful?	12	6	2
7. Does the draft MGN flow and is it understandable?	14	4	2

‘No response’ figures of 2 reflect the UK Chamber of Shipping (who responded on a returned copy of the MGN rather than completing the form) and the Marine Directorate (who submitted a written letter response). Both were fully considered.

Q3 results show: Yes = those who identified gaps; No = those who found the document adequate.

Key themes

The following themes were evident from the consultation responses:

• seaweed / algal farm-specific guidance needed
• proportionality concerns for small and micro-operators
• example templates not suited to aquaculture (OREI MGN (654) origins)
• through-life monitoring, maintenance and site safety accountability
• AIS data limitations - inadequate for inshore / small vessel traffic
• absence of implementation timelines and MCA review processes
• marking, visibility and electronic chart update timelines

Consultation questions and answers

1. Is the document fit for purpose?

Recap of consultee response: 

Yes	No	No response
11	7	2

The consultees welcome the intention to implement the new MGN to improve regulation and safety around the planning and operation of aquaculture sites. Concerns were raised around duplication of effort in applications, the dissimilarity between aquaculture and the OREI MGN (654), which was used to provide examples, and the impact that the application process might have on the time it may take to receive permission. 

MCA response: 

The MCA acknowledges these comments and has worked to demonstrate how this MGN seeks to provide guidance on the existing requirements of the marine license application, which aims to help applicants streamline the process and should reduce the duplication of effort and minimise time delays in the navigation risk assessment process. Work has been undertaken to consider the relationships between the OREI MGN(654) and aquaculture, focusing on keeping similarities in risk, providing proportionate advice dependent on the scale of the works, where necessary, and removing dissimilar advice or information between OREI and aquaculture.

2. Does it provide everything an applicant needs to complete the NRA?

Recap of consultee response: 

Yes	No	No response
10	8	2

Consultees raised the omission of detail within the draft MGN when considering specified timelines for MCA review, feedback and acceptance of submitted NRAs. Consultees claimed that without clear timelines, applicants cannot plan their submissions effectively, and the process could extend the already lengthy marine licence application period. 

Some consultees noted that the current OREI example hazard list includes risks not applicable to marine farms, which creates confusion. The document would benefit from being reworked to include only examples directly relevant to aquaculture. 

Small vessel regulator consultees recommended that developers be directed to consult local small boat pilot guides, cruising guides and recreational Sailing Directions, in addition to AIS data, to identify popular anchorages and passage routes. Specifically, guidance on notifying editors of Sailing Directions so that amendments can be issued promptly. 

Finally, it was mentioned that the requirement for applicants to submit a shapefile or GIS object may create issues for applicants who may not have the technical skills to create such files. It was suggested that guidance or instructions on alternative means could be provided. 

MCA response: 

Timelines for the application cannot be provided within this MGN due to many different considerations being made by the relevant Marine Licensing Regulators, depending on the region. Consideration towards timelines can be found on the relevant Marine Licensing Regulator’s websites to help provide certainty to some consultees. 

The OREI format is an established and effective method of developing NRA methodology when considering the installation of offshore objects, with many major developers referring to and using this format. However, the MCA acknowledges there may be differences between the OREI format and the requirements of the aquaculture industry. Therefore, the MCA has worked to develop this format in a manner which is aimed at being suitable to the industry and ensure proportionality. 

The MCA will consider the use of additional publications to better aid applicants in determining the suitability of chosen locations. Additionally, consideration will be made to those without access to suitable GIS platforms to still demonstrate the location and suitability of chosen areas.

3. Is there any aspect not fully addressed?

Recap of consultee response: 

Yes	No	No response
13	5	2

A range of consultees raised concerns in this question over the lack of mandatory regular inspections mentioned in the draft MGN, as well as requesting defined response times for damaged equipment by farm operators, and the inclusion of decommissioning bonds to ensure site restoration following bankruptcy or end of life. It was also raised that the possibility of UKHO notification and Notice to Mariners (NtMs) alone may be insufficient, arguing that notices should reach local harbours, marinas and Sailing Directions editors to ensure recreational users are informed promptly. Additionally, it was recommended that there be heavier weighting on monitoring and procedures for detecting and dealing with elements of the project which are damaged or off station. 

Aquaculture consultees raised a concern that the MGN only addresses risk from farms to other users, not the reciprocal risk to farms from fishing vessels, recreational craft and unauthorised visitors, and called for an approach consistent with the offshore renewables sector. Marine Licensing Regulator consultees noted the absence of any reference to the existing marine licence exemption for shellfish propagation activities and flagged planned tiered licensing reform for shellfish propagation. 

Finally, some consultees proposed targeted additions to the text covering storm damage, increased vessel movements contributing to collision risk, reduction in available sea room, and the enforceability of decommissioning obligations in Northern Ireland waters. 

MCA response: 

The MCA notes that this has been one of the most answered questions of the consultation and recognises the important issues raised by all consultees in answering this question. The MCA will consider these responses and incorporate those which are directly related to the methodology for assessing navigational risk. Although many important points were raised in the answers to this question, many fall outside of the scope of this draft MGN, but the MCA takes on board these concerns for future consideration of aquaculture sites.

4. Does it allow for a proportionate approach relative to the scale of the works?

Recap of consultee response: 

Yes	No	No response
8	10	2

Proportionality was discussed heavily by various consultees, from a range of sizes and organisations. The impact that taking a generic approach may have on small independent organisations was highlighted, stating issues around the cost of buoyage, the requirement of traffic survey assessments and the relevance of the MGN to small sites. However, other consultees stated the importance of not overlooking small sites, as the risks posed by either large or small sites can often be similar. Concerns were raised that the principle of proportionality of the MGN may result in easier processes for larger farms, whereas other consultees discussed how smaller farms had the risk of not using the same level of due diligence. 

MCA response: 

The MCA notes that the issue of proportionality is difficult to manage, with no suitable all-encompassing framework for each farm size. However, the risks imposed by any size farm can be considered similar, and it is important to emphasise the impact that even a small farm may have on shipping and navigation, depending on the placement and proximity to vessel traffic and other navigational hazards. Therefore, the MCA will consider proportionality when amending the MGN draft; however, it will continue to assess each application on a case-by-case basis to review its particular circumstances.

5. Are there any aspects which cause concern for your industry?

Recap of consultee response: 

Yes	No	No response
12	6	2

Responses highlighted a range of concerns regarding the proposed guidance. Aquaculture consultees argued that the measures would duplicate existing planning, environmental  assessment and marine licensing requirements, creating unnecessary regulatory burden without clear evidence of additional navigational risk. 

Concerns were also raised that expanded local consultation requirements could encourage exaggerated objections to developments. Recreational body consultees focused on the adequacy of site marking and the cumulative effect of aquaculture developments on safe navigation, particularly the risk of vessels being forced into narrower or more exposed waters in poor weather. 

Fishing consultees emphasised the long-standing problem of poorly maintained farm equipment causing fouling incidents and called for mandatory sharing of mooring data through established maritime information services. Technical concerns were raised about the use of multiple risk assessment methodologies within the guidance, with suggestions that acceptable risk thresholds should be determined by the relevant navigation authority rather than applicants. It was also noted that the introduction of further regulatory requirements would need careful management given existing tensions and relationship challenges within the sector.

MCA response: 

The MCA acknowledges the concerns raised during this section of the consultation and welcomes the comments made by a range of consultees. The aim of this draft MGN is to help applicants streamline their application process by providing guidance on the methodology for their NRA, therefore attempting to reduce the time constraints imposed by the already existing regulations. This does not count as a duplication of existing requirements. 

The marking requirements will be reviewed in consultation with the GLAs. The feedback raised on the appropriateness of yellow special marks for larger seaweed and algal farm installations will be discussed further and where appropriate clearer guidance in the document on cardinal marking will be provided.

6. Are the example templates clear and useful?

Recap of consultee response: 

Yes	No	No response
12	6	2

Templates from the document relate heavily to the OREI MGN (654), and many comment that these would be more appropriate if they were rewritten to incorporate aquaculture farms. Definitions within the templates need further definition to clearly define the different needs for the submission of an application. 

MCA response: 

The MCA note the templates relation to the OREI MGN (654) and will work to develop this template in a more aquaculture-focused output.

7. Does the draft MGN flow and is it easily understandable?

Recap of consultee response: 

Yes	No	No response
14	4	2

Many consultees found the MGN to be structured in a manner which flows and is easily understandable. Some comments were made highlighting that the MGN may be clear for larger organisations, but development could be made for smaller organisations. Additionally, suggestions were made to consider the location and placement of long lists of risk details. 

MCA response: 

The MCA has worked to provide more clarity and context on the wider process to improve the readability of the MGN for small-scale operators. Consideration will be given to the placement of large lists and details to improve flow.

8. Any suggestions for further improvements?

Consultees called for closer and more collaborative engagement between regulators (such as Crown Estate), industry and maritime stakeholders (such as aquaculture developers) during the development and implementation of the guidance. Several consultees emphasised the importance of involving aquaculture and fishing industry representatives directly in redrafting the guidance and supporting ongoing multi-stakeholder dialogue. 

Concerns were raised about the need for sufficient enforcement resources, with respondents noting that navigational risk assessments have limited value without effective monitoring and compliance activity. Suggestions were also made to improve the practical usability of the guidance, including the inclusion of real-world examples of seaweed farm structures and mitigation measures, greater consolidation and cross-referencing of related guidance documents, and improved consistency in terminology and formatting. 

Additional issues highlighted included the potential navigational implications of aquaculture developments on traditional sheltering areas, the need to consider light pollution impacts, and the importance of aligning the guidance with wider marine planning and maritime safety policies. 

MCA response: 

The MCA appreciates suggestions made for further improvement of this MGN and plans to engage with aquaculture developers and other marine stakeholders in further developing this guidance. The structure and presentation of this guidance will be reviewed to improve accessibility for small-scale operators and first-time applicants, additionally seeking to provide contextual background on the process. 

Feedback regarding collaboration with regulators and maritime stakeholders, and enforcement will be discussed with the relevant regulators.

9. Specific text comments or amendments

Summary of this section will be omitted to ease clarity and readability of the document due to the data delivery methods; comments and amendments have been fully considered by the MCA and will be incorporated where relevant.

Next steps

The MCA would like to thank all those who took part in this consultation and will consider the relevant points raised in this consultation. The MCA will aim to develop a new draft of MGN 687 (M+F) in Q3 of 2026.

Please contact navigationsafety@mcga.gov.uk if you have any questions regarding this consultation.