Although the collection and subsequent study of seashells is a serious scientific field known as conchology, most shell collectors are of the casual variety. Some people find it impossible to pass by a seashell which has caught their eye without stooping to pick it up and many people make a serious hobby from shell collecting, travelling many miles to visit a particular beach. In most of these cases the aesthetic appeal of the shell is what draws the beachcomber and not any scientific value.
Seashells are the hard exoskeletons of certain marine molluscs. The soft, inner parts of the creature that once inhabited the shell have usually been eaten by marine predators and coastal bird species or just rotted away by the time the shell washes up onto a beach.
There is a wide variety of seashells which are commonly found on the beaches, salt marshes and rocky shores of the UK and with thousands of miles of coast there is no shortage of opportunities for shell collecting. However, although shells are found throughout the UK, the beaches and coastal areas of the west such as Cornwall, Wales, the Outer Hebrides and western Northern Ireland will often provide a wider variety. This is because they are exposed to the storm detritus which comes in from the Atlantic.
By far the two most common types of shells found in the UK are sub-classes of the scientifically classified mollusca and are known as gastropods (snails) and bivalves. Many of the shells commonly found have no standardised common name although they will often be known by a wide variety of colloquial names particular to a certain region or county.
- Gastropods -
Gastropods are typified by one complete shell, often with a very obvious mouth. The small, delicate spirals of Bittium reticulatum are a good example of this structure as is the Common whelk which is a far larger and sturdier shell; both are a common find on many UK beaches.
Another familiar sight, although just as likely to be found with the marine mollusc still inside as that of an empty shell, is limpets. The flattened, conical shell of the limpet can be found in great abundance clinging onto rocks around intertidal zones and the fact that they are almost impossible to dislodge has led to the phrase 'to cling on like a limpet', meaning not to let go under any circumstances.
- Bivalves -
Bivalves are so called because they are comprised of two separate shells which are joined by a hinge. By the time they wash up on a shore the two halves have often become separated although the hinge itself may still be very obvious. Coming across a bivalve seashell where both shells are still joined can make for a special find.
Scallops are a type of bivalve and the Great scallop, which is found frequently on the beaches and estuaries of Scotland, is one of the largest common seashells found in the UK, typically measuring around 12.5 cm but often larger. Also common are smaller, more delicate scallops such as Palliolum tigerinum, measuring from a few millimetres to several centimetres. The colour ranges of this species through browns, pinks and purples, often flecked, spotted or mottled make it an appealing find.
The extremely common cockle shell is a familiar sight to almost every British child and, where these robust, white shells are found, they tend to occur in great abundance. Cerastoderma edule or Edible cockle is a very popular shellfish for eating and cockle harvesting both privately and commercially is common particularly around the beaches of East Anglia.
The distinctive Razor shell which has two, very long oblong (typically 7 to 10 cm), often papery thin parts, often seems to occur with both shells still intact despite its delicate appearance. This is also true of the more robust, thicker shelled mussel species commonly found which, like the cockle are also harvested for eating.
There are images of all the shells listed here along with many other common UK seashells at www.fredandsarah.plus.com
Perhaps a final word is necessary with regard to shell collecting in the UK. The gathering of empty shells is both a harmless and fun hobby although there are a few beaches in the UK where it is illegal to do so due to vulnerable eco-systems. However, shells offered for sale in shops have typically been harvested alive, often on a large scale commercial basis and sometimes illegally. This practice can be severely damaging to sensitive marine environments and buying from such suppliers is best avoided.