It’s not just the number of licenced mudlarkers that has increased in the past year. Estimates suggest at just one stretch of the Thames at Chiswick, in west London, the number of people exploring the foreshore at any one time during weekends has leapt from 10 to around 60, with similar numbers elsewhere along the river. Mr Clarke said: “Some are mudlarking and looking for buried objects, others are just lifting stones to see if they can find shrimps and other forms of river life. The common theme is they are exploring their surroundings closely because they have been forced to.