Keep in Touch

Subscribe to stay up to date on Seacology’s events, trips, and projects.

  • Email Address
  • This field is for validation purposes and should be left unchanged.


United Kingdom

Porthdinllaen Village


Conservation benefit: Replanting of seagrass areas damaged by mooring chains; new ecomoorings

Date Approved: 06.2020


This project protects seagrass, which traps more CO2 than any other marine ecosystem, slowing global warming.

In the shallow waters of the Irish Sea, off the northern Welsh coast, is one of the U.K.’s most spectacular seagrass meadows. These productive, expansive meadows provide many benefits, including:

  • Wildlife food and shelter
  • Reduction of storm damage and erosion
  • Better water quality
  • Food and economic security for fishing communities
  • Carbon trapping that exceeds rainforests, acre for acre

Much of the seagrass in Wales, however, has been lost. It is critical to save what remains, both for the benefits it provides and as a source of seeds for restoration efforts. In sites where only patches are left, natural regeneration is difficult or impossible, and active restoration is necessary.

Near the town of Porthdinllaen, chains used to moor boats in the harbor have literally scarred the seagrass meadows. As the moored boats bob in the water, the chains drag on the bottom, tearing up seagrass plants. The denuded patches are visible on Google Earth.

This project, Seacology’s first in the U.K., will restore at least ten separate scarred areas, totaling about a quarter of an acre. The acreage is small, but the impact could be big. Our partner, Project Seagrass, hopes that a well-done restoration project will serve as a model, paving the way for much more restoration.

Part of this project budget will be used to facilitate outreach, communication, and education with Porthdinllaen stakeholders. This includes bringing in a Welsh-speaking representative.

The planting will employ techniques used in successful restoration projects in Chesapeake Bay, adapted for the UK marine environment. Our partners will collect and prepare seeds, then plant them by hand, in burlap bags filled with sand, to protect them from the area’s high tides and hungry crabs.

Project Seagrass will also install several kinds of new seagrass-friendly boat moorings, designed for different kinds of boats.

Project Updates

February 2024

Project Seagrass has installed alternative mooring system (AMS) in the intertidal area. Unlike traditional moorings, these don’t damage the seagrass, which is growing right up to and around the system. Marked with a very large orange buoy, the AMS has attracted a lot of local attention. More will be installed as soon as a proper anchoring system has been added. Project Seagrass reports that its work on community engagement—crucial to success because some local boaters originally resisted changing the mooring systems that were damaging seagrass—is paying off.

Read more

June 2023

Project Seagrass will locate two new alternative mooring systems (AMS) in the subtidal area. They report that Seacology funding has helped build “significant interest in these systems as part of the solution to supporting seagrass recovery.” Evidence of this growing interest is that another project now aims to install eight more AMS along the North Wales coast.

Read more

February 2023

The first two alternative mooring systems installed in the inner harbor have not damaged the seagrass, except for a minor scouring during installation. (That has been rectified.) This is a big improvement over traditional moorings.

Project Seagrass is still working with the National Trust (the leaseholder for the site) and waiting to install more advanced moorings systems in the outer harbor. Winter storms dislodged some seedlings, which was expected; our partner will reassess in the spring. Some very good news: The National Trust is seeking government funds to install additional advanced mooring systems and restore more scarred areas. This is a testament to the work done through the Seacology-funded project.

Read more

June 2022

In March, our project partners installed the first two alternative mooring systems in the inner harbor at Porthdinllaen, and boat owners will be trying them out. More will be installed this summer. The seagrass seeds planted in burlap bags are now germinating. More seeds, collected after the seagrass plants have flowered, will be planted later.

Read more

February 2022

As the new seagrass plants grow, they will help recreate a healthy meadow with minimal fragmentation. More seeds were collected in August, and more reseeding is scheduled for February.

Our partner will install two models of moorings systems in the bay. Our partner has reached out to community stakeholders, building a steering group with representatives from conservation groups, government entities, boaters, and fishermen’s associations about the new mooring systems.

Read more

June 2021

After some weather-related delays, scientists and volunteers planted 10,000 more seeds (collected in 2020) at low tide near the end of March. The BBC Radio 4 program 39 Ways to Save the Planet featured the project and noted that seagrass could be one of the “hidden weapons in our fight against climate change.”

Read more

February 2021

Scientists and volunteers collected seagrass seeds in North Wales, and in October, 15,000 seeds were embedded in burlap bags and planted by hand. They were spread across two former moorings and an area damaged by a boat ramp.

Using imagery from drone flights, they are measuring mooring scars in the harbor’s seagrass. They are also choosing new eco-friendly mooring systems and getting permits to install them. Wales is in a full lockdown, so the timeline for installing them is uncertain.

Read more
- +