This small sea snail is best recognised by its thick shell, which is pale in colour and is rounded with a pointed spire, with spiral ridges along the surface.
Dog whelks are excellent indicators of specific marine pollutants. Tributyl tin (TBT) is a paint which has been used to get rid of crustaceans and other organisms that attach themselves to the hulls of boats and ships. Unfortunately when ingested by whelks it results in females developing male organs and becoming sterile. New legislation has now been passed restricting the use of TBT meaning that the populations of whelks which were affected by this substance are now recovering. That being said, the whelk is not under threat in Norfolk and UK waters.