Eco Moorings: How Advanced Mooring Systems Save Seagrass

Beneath the surface of our coastal waters lies a quiet world doing some of the planet's heaviest lifting. Seagrass meadows store carbon, shelter native wildlife, and protect our natural coastline from erosion. Yet, according to WWF, up to 92% of UK seagrass has vanished over the last century. Traditional moorings have played a part in that loss. Eco moorings are quietly changing the story.

Here's what we'll cover:

• What eco moorings are and how they work

• Why traditional anchoring damages seagrass meadows

• The Advanced Mooring System (AMS) explained

• Where PNAMS buoys fit in

• Famous landmarks like Studland Bay and the work happening there

• How to access eco moorings in Cornwall

Based at Mylor Yacht Harbour, Mylor Mooring Services designs, develops, and installs PNAMS systems across Falmouth Harbour, the Helford River, and St Mawes. We've spent over 30 years balancing vessel safety with environmental best practice.

What Are Eco Moorings?

Eco moorings are seabed-friendly mooring systems engineered to protect sensitive marine habitats. Unlike traditional moorings, which rely on heavy chains and concrete blocks scraping the sea floor, eco moorings keep their mooring lines suspended in mid-water.

The result? No chain drag. No seabed scour. No torn-up seagrass.

The most widely used version in the UK is the Advanced Mooring System (AMS), sometimes called sustainable moorings, eco-friendly moorings, AMS moorings, or low-impact mooring systems. Mylor Mooring Services is also developing its own Advanced Mooring System for vessel moorings, which we'll explain later in this guide.

These setups protect the environment for boats, visitors, and the wildlife below, using:

• A helical screw anchor driven into the seabed

• An elasticated rode that stretches and contracts with the tide

• Mid-water floats to keep the chain lifted off the seabed

• Lightweight materials with minimal counterweight chain

The whole system flexes with tidal movement rather than scraping across it. A traditional mooring leaves a circular scar in the sand. An eco mooring doesn't. Eco-moorings enable ecosystem recovery by allowing native marine plants to naturally recolonize previously degraded areas.

Why Traditional Moorings Harm Seagrass

To understand why eco moorings matter, picture what happens under a typical swing mooring at low tide. The mooring chain sits on the seabed. As the tide rises, it lifts. As it falls, it drops again. With every tidal cycle, that chain sweeps across whatever lies beneath.

The damage looks like this:

• Chain drag creates bare circular patches in seagrass meadows

• Concrete sinker blocks crush plants and disturb sediments

• Released sediment reduces water clarity, blocking the sunlight needed for growth

• Carbon stored in the bay's sediments leaks back into the sea

• Native wildlife, including bird life and fish species, loses breeding cover

Research from the Marine Conservation Society found a 212% increase in seagrass cover in Cawsand Bay four years after traditional moorings were swapped for AMS. That's recovery on a scale that genuinely shifts the conversation. Seagrass captures carbon up to 35 times faster than tropical rainforests, so every chain we lift off the seabed counts.

The engineering behind AMS is elegant in its simplicity. Rather than relying on weight to hold things in place, these systems use a screwpile anchor and elasticated tension.

Here's the breakdown:

Component	What It Does
Helical screw anchor	Screwed into the seabed, leaving a footprint as small as 16 cm
Elasticated riser	Stretches at high tide, retracts at low tide, keeping the rode taut
Mid-water floats	Hold the mooring chain suspended above the sand
Surface buoy	Marks the location and provides the mooring point

This setup means the only thing touching the sea floor is a single anchor point. Seagrass can grow right up to it. Native wildlife can pass underneath without obstruction. The whole system is designed to be both safe and self-correcting. For boats, the practical experience is similar to a standard mooring. You pick up the buoy, secure your lines, and you're set. For the seabed, the experience is night and day.

What Are PNAMS Buoys?

The Port Notice Advanced Mooring System (PNAMS) is a specific application of AMS technology, designed, developed, and installed by Mylor Mooring Services. It's important to make one distinction. Our current PNAMS (Port Notice Advanced Mooring System) installations are specifically designed to support marker buoys and Port Notice buoys rather than boats. These systems already help protect sensitive habitats throughout the Fal Estuary while we continue developing a boat-capable AMS system for future commercial use.

These buoys serve a different but equally vital purpose. They:

• Mark a voluntary no anchor zone around sensitive habitats

• Highlight speed restriction areas in busy harbours

• Identify navigation hazards or anchor zone boundaries

• Raise public awareness of marine protected areas across the west of Cornwall

We've installed PNAMS units off Trefusis Head in Carrick Roads, in St Mawes Harbour as 8-knot speed markers, and in the Helford River to mark seagrass beds. According to Falmouth Harbour, these "smart" buoys mark sensitive habitats of seagrass and maerl while keeping their own mooring risers off the seabed.

Behind the scenes at Mylor Mooring Services we're developing our very own Advanced Mooring System (AMS) designed to support full vessel moorings while significantly reducing contact with the seabed. Our current PNAMS systems support Port Notice and marker buoys, but the next generation of our design is being developed with the aim of providing an environmentally friendly solution for marinas and harbour authorities across the UK. Watch this space!

Visit our conservation moorings page for full technical details.

Marine Habitats That Benefit Most

Eco moorings make the biggest difference in places where the seabed isn't just sand. Sensitive habitats need this kind of careful approach.

The habitats most at risk include:

• Seagrass meadows (Zostera marina), which support seahorses, juvenile fish, and crustaceans

• Maerl beds, slow-growing pink coralline algae that take decades to recover from damage

• Reef systems in places like the Fal and Helford Marine Protected Area

• Native oyster beds, now severely depleted across UK waters

• Nature reserve zones that act as nursery grounds for commercial fish species

In Cornwall, our work with Falmouth Harbour Commissioners and St Mawes Pier & Harbour Company aims to protect those habitats without restricting safe access for boats. Learn more about our services across the region.

Eco Moorings in Cornwall

If you're a harbour authority, conservation body, or marina operator looking to install conservation moorings or PNAMS marker buoys, we're set up to help. Our team uses survey-grade GPS and digital charting to ensure every system is laid exactly where it needs to be.

Our approach typically includes:

1. Site survey and habitat assessment

2. Consultation with stakeholders (harbour authorities, MMO, conservation groups)

3. Installation using helical screwpiles and hydraulic equipment

4. Regular inspection and maintenance

5. GPS positioning for traceability and compliance

Over the past two years, we've installed eleven PNAMS systems across the Fal and Helford Marine Protected Area in partnership with Falmouth Harbour Commissioners, St Mawes Pier and Harbour Company, and other stakeholders. Each one quietly does its job while the seabed below recovers.

Pro tip: If you operate in a Marine Conservation Zone or Special Area of Conservation, eco moorings can strengthen your licensing position with the Marine Management Organisation. They're increasingly recognised as best practice for environmentally sensitive sites, and you can locate active installations using Google Maps coordinates we provide on handover.

For broader marine support, take a look at our mooring installation services or get in touch directly to discuss your project.

Approved UK Seaflex Installers

Alongside our own PNAMS systems, Mylor Mooring Services is also an approved installer of Seaflex mooring systems.

Developed in Sweden, Seaflex replaces traditional heavy chains with elastic mooring elements that expand and contract with tidal movement. This keeps the mooring line under constant tension, reduces seabed contact and offers a low-maintenance alternative for many marine applications.

As one of the few approved Seaflex installers in the UK, we're able to advise harbour authorities, marinas and waterfront property owners on whether this system is suitable for their project.

As environmental standards continue to evolve, low-impact mooring technology is becoming an increasingly important part of harbour management. Through continued innovation, including our own developing AMS design and approved Seaflex installations, Mylor Mooring Services is helping support safer boating while protecting Cornwall's marine habitats for future generations.

Protect Our Seabeds With Mylor Mooring Services

Seagrass loss is one of the quieter environmental crises, but the solutions are already in the water. Eco moorings prove that sustainable boating and thriving marine habitats can coexist. The technology works, the science backs it, and the impact is measurable.

Key takeaways:

• Eco moorings keep mooring chains off the seabed, protecting seagrass and maerl

• The AMS uses a helical screw, elasticated rode, and mid-water floats

• PNAMS buoys mark conservation zones and Port Notice areas, not vessels

• Studland Bay and Cawsand Bay show 200%+ seagrass recovery using AMS

• Cornwall's Marine Protected Areas benefit from this low-impact approach

At Mylor Mooring Services, we design, build, and install PNAMS systems across Cornwall's coastline. From Trefusis Head to the Helford River, our work supports harbour authorities and conservation partners. Get in touch to discuss eco moorings for your project.

01326 373 777

07743 926429

office@mylormooringservices.co.uk