Mudflat outings and clam digging, done safely

Land the sea lends you for a while

A mudflat is seabed that is exposed at low tide and covered again at high tide. Wide and flat, it feels like a field that is easy to walk across, but within a few hours the same spot is sea again. It is an ecosystem of clams, crabs and worms, and in many places it is also a workplace where local fishing communities earn their living. So a mudflat outing should start with two checks: when the water comes back, and whether you are allowed to dig for clams there at all.

Check the tide first

A mudflat outing starts with a tide table. The rule is to go out around the time of low tide and come back with plenty of margin before the water starts returning. On a mudflat, the water does not simply advance from the open sea; it runs in first along channels called tidal creeks, which can cut off the route you walked in on from behind you. On flat ground, water spreads faster than you expect. Set an alarm on your phone for when to head back, and leave immediately if fog rolls in, because it is easy to lose your bearings.

• Check that day's low and high tide times
• Set an alarm for when to head back
• Remember your route and where the creeks are
• Do not go out in fog, rain or strong wind

How to avoid being cut off

Most mudflat accidents happen when people get absorbed in digging and lose track of time. When the ground underfoot gets wetter or water starts flowing in the creeks, stop what you are doing and head for shore. The farther out you are and the softer the mud, the longer it takes to walk back, so build that into your timing. Never go out alone, and keep children within arm's reach. If rising water does cut you off, do not try to wade across a channel; get to higher ground and call emergency services or the coast guard with your location. This is general safety information; on-site guidance and closures come first.

Village fishing grounds and no-harvest areas

A mudflat is often not open ground where anyone can dig. In Korea, many mudflats are village fishing grounds where the local fishing cooperative raises and manages clams, and digging without permission can count as illegal harvesting. Mudflats in national parks or protected areas may ban harvesting entirely. The surest option is a mudflat experience site run by a fishing cooperative or local government. These sites set the areas and hours you may enter, the tools you may use and how much you may take, so follow their guidance. Rules and boundaries can change, so check official local information.

Shellfish toxins and hygiene

Clams, oysters, mussels and other shellfish can, at certain times, build up toxins produced by plankton in the seawater. You cannot tell by looking, and cooking may not destroy them. Areas where toxin levels exceed safety limits are closed to harvesting and announced officially, so check local government and fisheries agency notices before you go, and neither dig nor eat shellfish from closed areas. If your lips or fingertips tingle or go numb after eating shellfish, call emergency services or get medical help immediately. Keep cuts on your hands and feet away from seawater and mud, and people with liver disease should not eat shellfish raw.

Clothing and kit

Mudflats hide broken clam and oyster shells and discarded sharp objects, so walking barefoot can cause serious cuts. Wear boots or mudflat shoes that cover the ankle and will not pull off, and wear gloves. There is no shade, so bring a hat, sunscreen and drinking water. Wear clothes you do not mind getting muddy, and leave washing water, spare clothes and a towel in the car. If you sink knee-deep in soft mud, do not yank your legs out; lower your body to spread your weight and work your way out slowly.

• No bare feet: ankle-high boots
• Gloves, a hat, sunscreen and water
• Only the tools and baskets the site allows
• Spare clothes, towel and water in the car

Digging with care

Filling in the holes you dig reduces harm to the creatures around them. Put back very small clams and crabs carrying eggs, and take only what you will eat. If you pick up crabs or worms to look at, return them where you found them. Leave no rubbish, and no broken containers or bits of gear either. For children, spending time together looking at what lives in the mud makes for a richer outing than digging up as many clams as possible.

Cleaning and storing clams

Freshly dug clams are full of sand and mud and need purging. Soak them in seawater, or water salted to a similar level, and leave them somewhere dark and cool, and they will spit out the sand on their own. Keep them cold in a cool box on the way home, and do not leave them in the sun. Cook purged clams thoroughly and as soon as you can. Throw away any that stay shut after cooking, have cracked shells or smell wrong. If you get stomach pain, diarrhoea or tingling after eating them, do not wait it out; see a doctor.