Port Isaac Seaweed Farm
Source: gov.uk (2025-11-17)

Information relating to marine licence applications for the construction of a seaweed farm in the Port Isaac Bay area off North Cornwall (case reference (MLA/2022/00180).

Key facts
- Case name: Seaweed Farm, North Cornwall
- Applicant name: Penmayn Limited
- Marine licence reference number: MLA/2022/00180
- Type of application: Aquaculture
- Date received: April 2022
- Decision: Granted with conditions, subsequently suspended
- Location: Port Isaac Bay, off the North Cornwall coast
- Link to the case on the public register (https://marinelicensing.marinemanagement.org.uk/mmofox5/fox/live/MMO_PUBLIC_REGISTER)
Case summary

In April 2022 the Marine Management Organisation (MMO) received a Marine Licence application for the construction of a one square kilometre (km²) seaweed farm in the Port Isaac Bay area off North Cornwall. The main infrastructure of the farm will include long lines, long anchored with a maximum of 120 screw anchor moorings. Deployment of the seeded seaweed long lines are intended to take place when the main infrastructure has been established. The licence included harvesting of seaweed to take place between April and June and/or October and November annually.

On the 10 August 2023 the MMO made a determination on the application. The MMO considered that the licence should be granted with conditions, with an end date of 09 August 2048. A copy of the marine licence is available on the Public Register by searching for the marine licence reference number stated above.

On the 29 August 2025, following an internal review of the licence (see below), the MMO considered that the licence should be suspended for 18 months, until 27 February 2027. A copy of the suspension letter is available on the Public Register by searching for the marine licence reference number stated above.

Internal Review

Following a submission by the Save Port Isaac Bay Group in July 2024, which included substantial information requesting that the MMO reconsider its decision to grant the marine licence for Port Isaac seaweed farm, the MMO undertook an internal review of the licensing decision. The review has now been completed, with external advice sought from Royal Haskoning DHV in doing so.

The MMO’s full response to this review, including any further actions is available on the Public Register by searching for the marine licence reference number stated above.

Under section 72 of the Marine and Coastal Access Act 2009 (“MCAA”), the MMO has the authority to vary, suspend or revoke a marine licence if it appears that such action is warranted:
- because of a change in circumstances relating to the environment or human health;
- because of increased scientific knowledge relating to either of those matters;
- in the interests of safety of navigation;
- for any other reason that appears to the authority to be relevant.
Following the review, the MMO has concluded that, at this time, it is appropriate to give Penmayn Ltd. (the licence holder) the opportunity to respond to our concerns and provide further information. This will help determine if the environmental conditions at the site could compromise the installation or mooring of the seaweed farm.

To facilitate this, the MMO has suspended the licence for a period of 18 months, allowing time for the licence holder to review the MMO’s findings and submit a detailed response. During this suspension, no licensed activities may take place. The licence may be reinstated if the MMO is satisfied that the farm’s design is safe and suitable for the site. However, if the MMO is not sufficiently assured of the safety and viability of the proposed activities, we may exercise our powers under Section 72 of the MCAA to revoke the licence.

Next Steps

The MMO has now suspended licence MLA/2022/00180 and has communicated the requirements to the licence holder. We are currently awaiting their response.

This page will be updated as the situation progresses, including when further information is received, when it is under review, and if the MMO determines that re-consultation is appropriate based on the new evidence.

Further Information

On 29 August 2025, following an internal review of the licence (see above), the MMO considered that the licence should be suspended for 18 months, until 27 February 2027 or until the Licence Holder submitted information to the MMO that satisfied the MMO that the suspension could be lifted.

On 30 September 2025 the MMO received an appeal against the suspension from the Licence Holder, Penmayn Limited, via the First Tier Tribunal.

On 29 October 2025 the licence was varied to include a condition requiring information related to the safety of the structure. The effect of this variation was that only if this condition could be satisfied could works commence. The decision to vary the licence was taken in error as a result of a misunderstanding.

However, as this new condition now prohibits all works until the Licence Holder submits information to the MMO that satisfies the MMO as to the safety of the seaweed farm structure, the MMO has decided not to defend the appeal at the First Tier Tribunal and has asked that the Tribunal withdraws the Suspension Notice.