Why the coast is more fragile than it looks

A sand dune looks like a solid, sandy hill. In truth it is a living structure, knitted together by marram grass, lichen and a thin skin of roots, built grain by grain over decades. Break that surface and the wind does the rest: a small shortcut becomes a blow-out, a blow-out becomes a gap, and the sea reaches a little further inland with every winter storm. Cliffs tell the same story in a different material. They erode naturally, and the birds that nest on their ledges — kittiwakes, fulmars, guillemots, puffins — have nowhere else to go. Between the two lies the intertidal zone, where limpets, winkles, crabs and anemones already live at the edge of what they can tolerate, waiting out every tide.

Leaving no trace isn't about being precious. It is simply making sure that after your visit the coast is still doing its job — for wildlife, for the people who live and work there, and for whoever walks it next.

Take everything home, and then a little more

Pack out what you pack in, including the things that feel harmless. Orange peel, apple cores and banana skins take far longer to break down than most people assume, and they pull rats and gulls into places they shouldn't be. Cigarette ends are plastic, not paper. Wet wipes, cotton buds and balloon ribbons turn up on tidelines everywhere, and a length of fishing line or a stray hook can kill a bird or a seal long after you've gone.

• Carry a small bag for rubbish and pick up two or three extra items if you can — the tideline collects what everyone else dropped upstream.
• Never leave a filled dog poo bag hanging in a bush. If you bagged it, take it home.
• Feed nothing. Gulls that learn to associate people with food become aggressive, and hand-fed seals lose the caution that keeps them safe.
• If you need the loo and there are no facilities, go at least 30 metres from the sea, any stream and any path, in a hole about 20cm deep, and carry the paper away with you.

Give the locals some room

The coast is a nursery, a larder and a resting place, often all at once. Grey seals haul out to digest, moult and raise pups, and they need undisturbed rest far more than they need a closer photograph.

• Watch seals from at least 100 metres on land and further at sea. If an animal lifts its head, you are already too close. Never come between a seal and the water, and never let a dog approach.
• Between March and July, cliff-nesting seabirds are at their most vulnerable. Keep to the cliff-top path rather than the edge, keep dogs on a short lead near colonies, and leave the drone at home — it reads as a predator to a bird that has already flown hundreds of miles to breed.
• In a rockpool, wet your hands, look gently, and put every stone and creature back exactly as you found it. Limpets clamp down and cannot easily re-seal if prised off. Take photographs, not souvenirs; on some beaches removing pebbles or shells is actually an offence.

Fires, BBQs and the grass that never grew back

A scorch mark on dune turf or coastal heath can still be visible a decade later, and dry grass in a sea breeze carries fire fast. Many councils now ban disposable BBQs on beaches and in dunes for exactly this reason, so check local notices before you set off. A small camping stove is almost always the better choice.

If fires are permitted where you are, use an existing ring or fire pit, keep it small, never leave it unattended, and burn only dead wood that is already down and part of the woodpile at home — not branches snapped from living trees or timber prised off a fallen log, which is habitat for beetles and fungi. To put a fire out, douse it with water until the ashes are cold to the touch, then take the ash home in a bag. Sand does not extinguish a fire; it insulates it, and the embers can smoulder underground until the wind returns.

Feet do more damage than you think

Most coastal erosion caused by visitors is caused by feet, not storms. Dunes and vegetated shingle are the worst affected, because the plants that hold them together cannot survive trampling.

• Stay on the path, even when it is muddy or the direct route looks shorter. Cutting a corner widens the path, which starts a new one.
• Use boardwalks and steps over dunes, and never slide or run down a dune face — the loose sand you shift is the sand the dune was holding.
• Keep well back from cliff edges, including grassy ones. Undercutting means the lip can give way without warning, taking soil and vegetation with it.
• Leave cairns, stacked stones and driftwood sculptures alone. Moving shingle or rocks can undermine a beach that is already shrinking, and rearranged stones disturb the animals sheltering underneath.
• On saltmarsh and mudflats, follow the marked line rather than fanning out, and turn back before the mud softens.

Small habits, repeated by thousands

Before you go, check the tide table and the local notices — spring tides move quickly and cut off headlands that look perfectly safe on a falling tide. Tell someone your route. Visit quieter stretches rather than the same honeypot car park, and if a beach or path is closed for nesting or restoration, take it as a good sign rather than an inconvenience.

None of this requires special kit or expertise. It is a handful of decisions made quietly, over and over, by people who love the coast enough to leave it exactly as they found it. Do that often, and it stays worth returning to.