The story of seagrass and Seawilding – Planting hope at Loch Craignish

There’s something quietly revolutionary about planting beneath the sea. Recently, I visited Loch Craignish on the west coast of Scotland, a place I’ve long felt pulled to. Tucked into its tidal folds is one of the most inspiring examples of ocean restoration in the UK: flourishing seagrass meadows and the resurgence of native oysters, both hand-planted by the small but mighty team at Seawilding.

They’re a charity I’ve supported for several years now, driven by deep admiration for their vision and their very grounded approach to community-led marine restoration. Seeing the seagrass and oysters for myself was emotional. Not just for what they are now, living, breathing underwater ecosystems, but for what they symbolise: healing, resilience, and the ripple effect of local action in the face of a planetary crisis.

Seagrass: The Unsung Ocean Ally

Let me tell you why I’m obsessed with seagrass.

This humble plant is one of our most powerful blue carbon tools, it is in fact a keystone species. Seagrass meadows, though covering only 0.4% of Loch Craignish, host an incredible 68% of its biodiversity. They sequester carbon, provide vital habitats, and support biodiversity. Yet, globally, 92% of seagrass has now gone.

That’s why Seawilding’s work is so vital. Since 2021, they have planted over 400,000 seagrass seeds and 18,000 rhizomes in Loch Craignish. In 2024 alone, they planted 8,000 rhizomes into a well-oxygenated area of seabed and after six months they observed a five-fold increase in coverage. Their goal for 2025 is to plant approximately 1/3 hectare.

Why seagrass matters in the climate crisis

1. A blue carbon powerhouse

Seagrass can sequester carbon up to 35 times faster than tropical rainforests. It captures and stores carbon dioxide in its roots and surrounding sediment, locking it away for thousands of years.

2. Only 0.2% of the seafloor, but crucial

Seagrass meadows cover a tiny fraction of the ocean floor globally, yet they absorb about 10% of the ocean’s carbon each year. That’s a huge impact for such a small footprint.

3. Restores biodiversity

Seagrass is a haven for life. A single hectare can support up to 80,000 fish and 100 million invertebrates, acting as nursery grounds for species like cod, pollock, sea horses and even juvenile sharks.

4. Filters and cleans the water

Seagrass traps sediments, absorbs excess nutrients like nitrogen and phosphorus, and improves water clarity, creating healthier marine ecosystems.

5. Protects coastlines

By stabilising sediment and buffering wave action, seagrass reduces coastal erosion and helps protect communities vulnerable to rising seas and storms.

6. In decline, but restorable

Globally, we’ve lost around 29% of seagrass meadows since the late 19th century, mostly due to pollution, coastal development and dredging. But seagrass can recover with human support. Restoration projects like Seawilding’s prove that.

7. Locally powerful, globally vital

Unlike some climate solutions that require vast scale, seagrass restoration can be community-led, done in lochs, bays and estuaries. Every plug planted is an act of climate resilience.

Native Oysters: Ecosystem Engineers

Equally inspiring is Seawilding’s native oyster restoration project. Native oysters (Ostrea edulis) are “ecosystem engineers,” filtering and cleaning water, sequestering carbon, and contributing substantially to inshore biodiversity by creating reefs that become fish spawning grounds and nurseries.

Historically, Loch Craignish supported a large population of native oysters, but due to overexploitation and pollution, they have all but disappeared. Seawilding aims to restore up to 1 million native oysters to the loch. As of now, they have restored 350,000 native oysters to the seabed .

These oysters are grown in floating nurseries until they reach a suitable size to survive predation. Community volunteers then broadcast them by hand into the shallows. Excitingly, in 2024, for the first time, Seawilding observed clear signs of breeding success, juvenile oysters appearing in significant numbers.

Why native oysters matter

1. They’re ecosystem engineers

Native oysters (Ostrea edulis) create reef-like structures that boost biodiversity, offering shelter and spawning grounds for fish, crabs, starfish and countless other marine species.

2. Natural water purifiers

Each oyster can filter up to 200 litres of seawater a day, removing excess nutrients, particulates and pollutants. Clearer water means more light penetration for seagrass and healthier coastal habitats.

3. Blue carbon heroes

Oyster reefs capture and store carbon in their shells and the sediment they stabilise. While not as carbon-rich as seagrass, they play a key role in locking carbon in seabed systems.

4. Critically endangered in the UK

Native oysters have declined by 95% in European waters due to overharvesting, pollution, disease and habitat loss. Restoring them is vital for ecological balance and cultural heritage.

5. Local food, global benefit

Sustainably restored oyster populations offer a low-impact protein source that doesn’t need feeding or antibiotics, supporting circular economies and food security in coastal communities.

Did you know there’s a problem with invasive oysters in the UK?

While native oysters (Ostrea edulis) are quietly being reintroduced to places like Loch Craignish, there’s another story unfolding along our coasts.

The Pacific oyster (Magallana gigas) was introduced to the UK in the 1960s for farming, after native stocks collapsed. Hardy and fast-growing, they’ve since escaped into the wild and are now classed as an invasive species in many parts of the UK, particularly along the south coast.

Unlike our native oysters, which form biodiverse, reef-like habitats that support countless other species, Pacific oysters often form dense, monoculture reefs. These can smother soft sediments, alter the chemistry of the ecosystem and outcompete native oysters for space and resources.

They’re also tough to manage. Once they establish, they spread quickly, especially during warmer summers and their presence threatens the delicate recovery of native oyster populations.

This is why Seawilding’s focus on native oyster restoration is so important. By creating thriving, resilient oyster reefs in carefully chosen locations, they’re helping rebalance the ecosystem, one shell at a time.

Restoring with and for Community

What I love most about Seawilding is their community ethos. This isn’t about outsourcing restoration. It’s local people, trained and empowered, planting hope into the seabed. Their model could shift the future of coastal communities, not just environmentally, but economically too.

As someone who tells stories at the wild edge, I’m deeply moved by this work. It’s a reminder that not all heroes wear capes. Some wear wetsuits, wade into lochs and plant life back into places it was once lost.

Want to help?

• Learn more about Seawilding’s work
• Support their ongoing seagrass and native oyster restoration projects
• Share this post and spread the word
• Donate, volunteer, or get involved in citizen science

This is ocean healing in motion

Not abstract. Not out of reach. Just beneath the surface. Loch Craignish has stayed with me, and I’ll carry the image of those green blades dancing in the tide and the resurgence of native oysters as a reminder of what’s possible when we act with love for the sea.