Collecting the empty shells of dead molluscs from the strandline has no impact at all on the habitats or species concerned – the individuals were already dead, and their shells were destined to become particles of sand. Unfortunately many specimens found in this way will have been damaged to some extent by wave action, but nevertheless it is possible to find almost perfect examples. The best time to search is just after high tide after violent weather. Beachcombing requires no equipment other than a good pair of eyes, and it adds much to a stroll along the beach!
To get hold of perfect specimens amateur conchologists usually move on to capturing living animals, killing them, and then preparing the shells. Obviously this is going to have an impact on both the species concerned and the habitat, but if done responsibly the damage can be minimal.
Most bivalves, and many other molluscs live their lives buried in sediment of some kind or another. The bivalves dig down, and some snails plough through – but however they get there they are hidden below the surface. Some simple equipment is needed to find them, either a small sieve or a spade. Since each tide will cover any damage and re-distribute the sediment, this form of collecting does little harm.
When it comes to either of these it is important to remember that the organisms (including the molluscs) that are found living there will have taken a long time to build up their communities. A rock does not just have a top and a bottom – the way it sits in relation to the waves and currents, and the way it faces the sun are all equally important. Rocks should always be replaced exactly as they were found (see ‘Collecting Cowry Shells’). Living corals should never be harmed in the search for shells!
When you have a live animal and you want its shell there is no alternative but to kill it. They should never be boiled, since this will damage the shell, and the best way to kill and preserve is to place them immediately into 70% alcohol. If this is not available then a second best is to put them in the freezer, since this will cause only slight shell damage.
Repeated freezing and thawing will allow the body to be washed out quite easily, but the best method by far is to place the dead molluscs near an ant nest. The ants will clean out most of the meat, and what is left can be washed away. Once cleaned the shells should be dried thoroughly and kept out of direct sunlight.
Many people are content to keep their shells in cardboard containers – only taking them out occasionally, but most like to be able to see them easily. Making a tasteful arrangement against a suitable background (velvet?) and housing the collection in a glass-topped cabinet is an excellent way to both store and display.
Other articles by John Blatchford