There’s something irresistible about the pull of the coast. That first lungful of sea air, salty, tinged with seaweed and adventure. The sea breeze carries the zest of freedom, and grains of sand lodge between your toes like natures souvenir. Beyond the views and the sound of the waves lies a world that few truly see - marine habitats nestled on the seabed lay hidden beneath the surface.

Into the Blue: A hidden world unfolds

One summer afternoon in Cardigan Bay, I slipped into the cool water having donned my wetsuit, a snorkel and mask. 

Below the gentle waves, the underwater world unfolded like a living tapestry. Sunlight filtered through swaying fronds of seaweed, casting flickering shadows across a rocky reef. Then, motionless but watching me, I glimpse a small-spotted catshark, perfectly camouflaged among the plant life below. Just a metre away, I’d almost missed it.

Life on the ocean floor

This secret world of mudbanks, maerl beds, sandbanks and chalk reefs, kelp forests, seagrass meadows, cold-water corals and more thrives out of sight beneath the UK’s coastal waters. 

Each habitat plays a vital role in the marine ecosystem. Seagrass beds and maerl, for instance, are nurseries for juvenile fish, while reefs offer shelter, food and spawning grounds. The seabed isn’t just the sea’s foundation - it’s a dynamic, life-supporting system.

Signs of change

But time and tide have changed it. Over years of exploring these underwater habitats, I’ve noticed and heard of subtle shifts. From the shore, it’s almost impossible to spot, but beneath the waves, the signs are there. 

Human activities like bottom trawling, dredging, anchoring and pollution all reshape the underwater landscape in ways we’re only beginning to understand. Flattened reefs, sediments stirred into murky plumes, and once-common species reduced in numbers. Sometimes, the only clue is what washes up on our beaches, a diverse array of lifeless animals like catsharks, starfish, crabs or coral, fragments of a deeper story unfolding out of sight.

Cardigan Bay’s coastal riches

Back in Wales, efforts to understand and protect marine habitats are ongoing. Here, bottlenose dolphins glide over sandbanks, while scallops nestle into the sand and gravel beds below. Rocky reefs covered in sponges, anemones and sea squirts form complex structures where species jostle and coexist, every nook and crevice alive with movement.

Hope Below: What protection can do

There is hope. Skomer Marine Conservation Zone (MCZ) in Pembrokeshire, the first and only MCZ in Wales, protecting 1,400 hectares of seabed since 2014 (previously designated as a Marine Nature Reserve in 1990).  

Strict byelaws ban dredging and mobile fishing gear, whilst no-anchoring zones help to protect seagrass beds and designated moorings discourage habitat disturbance. Monitoring reveals thriving seabed communities: sponge biodiversity remains among the richest in the UK, scallop densities have steadily risen and seagrass meadows have expanded since the 2010s. Long-term data show that these protections have enabled diverse and resilient habitats, from colourful coral-like pink sea fans to carpeted eelgrass meadows and abundant crustaceans, to persist and flourish. 

Skomer and other highly protected sites reveal that it is true, with protection and patience, the ocean can bounce back.

Lamlash Bay on the Isle of Arran, Scotland is home to the UK’s first community-led No Take Zone. Once impacted by years of overfishing and dredging, this small stretch of seabed was closed to all extractive activities in 2008. The area has shown remarkable signs of recovery. Kelp forests have thickened, scallop and lobster numbers have increased, and marine life is returning in greater diversity and abundance. It’s a powerful reminder that when we give the ocean space and time to recover, it can and it does thrive again.

Lyme Bay on the south coast of Devon and Dorset was closed to bottom-towed fishing in 2008 to protect its reef habitats. Since its closure the area has seen a marked increase in marine life and habitat diversity. Fragile species like pink sea fans and maerl have flourished while kelp and sponge communities have expanded. Managed through a collaboration between local fishers, scientists, NGO’s and regulators Lyme Bay shows that with the right protections and partnerships, both nature and communities can thrive.

A blueprint for a thriving sea

When marine habitats thrive, you can feel it. The water pulses with life. You see height, colour, movement, everything from darting fish to slow-gliding rays, all with a role in the intricate web of marine life. This is what success looks like, this is what our seabed should look like: a vibrant, layered ecosystem teeming with biodiversity.

Your invitation to dive in

So next time you’re at the beach, take a moment. Let the sea breeze sting your cheeks, taste the salt on your lips, and listen to the rhythms of the tide. If you dare, grab a snorkel and mask and take the plunge. Beneath those waves is a world wilder than any wildlife documentary or social media feed. The seabed might be hidden, but it’s far from lifeless, it’s the beating heart of our blue planet and deep down we all know it.