A Practical Guide to Beach Combing and Its Ethics

Why the strandline is worth your time

The strandline is the dark ribbon of seaweed, twigs, feathers and bladderwrack that marks the last high tide. It is the most productive place on any British beach, and it changes with every tide. After a spring tide or a westerly gale, the same stretch of shingle you walked last week can look entirely different.

What turns up is a mix of the natural and the man-made. You might find mermaid's purses — the empty eggcases of skates and rays — cuttlefish bone, whelk eggcases that look like strings of papery coins, sea beans, driftwood, and sea glass worn smooth by decades of tumbling. You will also find plenty of plastic, which is precisely why a bag and gloves are part of the kit.

Timing your trip: tides, storms and seasons

Beach combing is mostly a matter of turning up at the right moment. A few rules of thumb:

• Tide. Aim to arrive two hours before low water and work the falling tide out, then follow it back in. Never let a headland or a rocky point cut you off — tides on flat sandy beaches can move faster than you walk.
• Spring tides. These fall around the full and new moon, twice a month, and expose the most ground. The day or two after a spring tide is prime.
• After a storm. The first low tide after a blow is the best of the year. Go within 24 hours if you can, before the next big tide rearranges everything.
• Season. Winter strips beaches bare of visitors and often leaves the best finds. Summer brings the crowds, the litter and the nesting birds.

Check a tide table before you leave the house, not on the beach with no signal. On estuarine or fast-draining coasts, the difference between a safe hour and a stranded one is often minutes.

What to take (and what to leave at home)

Keep it light and practical. A sturdy bucket or a cotton tote beats a plastic bag, which tears and adds to the problem. Take gardening gloves or a litter picker for anything sharp or questionable — broken glass, fishing hooks, syringes and rusted metal all turn up. Sturdy boots with grip are essential on wet rock, and a waterproof layer is worth carrying even on a bright forecast.

Add a phone for photographs, a small notebook, hand sanitiser and a couple of plasters. A flask is optional but rarely regretted. Leave the hammer and chisel at home: breaking into rock or prising stones off a reef damages a habitat that took years to form.

What's fine to pocket, and what stays put

This is the heart of it. The general principle is simple: take what is already dead, discarded or manufactured, and leave anything alive or still doing a job.

• Fine to take in small amounts: sea glass, sea pottery, a few empty shells, cuttlefish bone, driftwood, mermaid's purses that are dry and empty. A handful for your windowsill harms nothing.
• Leave where it lies: anything with an occupant. A whelk shell with a "door" sealed across the opening, a cockle that feels heavy, a crab in a rockpool — put it back exactly where you found it. If it smells, it is occupied.
• Never take: live shellfish, starfish, anemones, corals, seaweed still attached to rock, pebbles and sand. Seaweed anchors itself and shelters dozens of tiny creatures; detached weed on the strandline feeds sandhoppers, which in turn feed the waders.
• Live eggcases. A mermaid's purse with a yolk inside, or one that is soft and pale, may still hold a developing skate. Return it to the water gently.

There is also the law to consider. Removing sand, shingle or pebbles in quantity is restricted on most beaches, much of the foreshore is owned by the Crown or a local authority, and many sites — nature reserves, Sites of Special Scientific Interest and Marine Conservation Zones — have bye-laws that prohibit collecting altogether. Disturbing protected species, or nesting birds such as ringed plover and oystercatcher, is a criminal offence. A pocketful of sea glass is one thing; a boot full of shingle is quite another.

Recording instead of collecting

Photographs last longer than a jar of shells and cost the beach nothing. A phone snap with a coin or a ruler for scale tells you far more than a fading memory, and it can be genuinely useful. Eggcase recording schemes rely on members of the public logging what they find, and that data feeds directly into conservation work on skate and ray populations.

If you find something odd — a stranded jellyfish, an unusual fish, a mass of small plastic pellets known as nurdles — note the location, the date and the state of it, and report it. If you spot a seabird tangled in fishing line or an animal in distress, keep your distance, keep dogs away, and call the relevant wildlife rescue or the coastguard rather than intervening yourself. Seals, in particular, need at least 100 metres of space, and a pup on its own is usually just waiting for its mother, not abandoned.

Leaving it better than you found it

Take a bag for litter and fill it as you go — fishing line, balloon fragments and wet wipes are the worst offenders for wildlife. On a busy beach, that single bag makes a measurable difference. The September beach cleans are a good way to learn a stretch of coast properly, and you will pick up more local knowledge in an afternoon than in a year of reading.

Step carefully on shingle, where nests are little more than a scrape in the stones, and turn any rock you lift back exactly as you found it, damp side down. Keep to paths on dunes; the grass holding them together is more fragile than it looks. Then go home with photographs, a lighter bag and the sense that you left the tide line a little better than you found it.