Intensive Mesolithic exploitation of coastal resources? Evidence from a shell deposit on the Isle of Portland (Southern England) for the impact of human foraging on populations of intertidal rocky shore molluscs

Recent research has indicated the importance of marine foods in the diet of some late Mesoltihic (c500-4000 cal BC) populations in western Europe, but little is known of the role of such resources in the earlier Mesolithic. Analysis of assemblages of marine molluscs from the shell midden of Culverwell, Isle of Portland, showed changes int he absolute abundance of the three dominant species, as well as changes of mean shell size and age-class frequencies int he species Monodonta lineata (da Costa), through the midden. It is suggested that these changes result from the impact of human foraging on the populations of these molluscs, and that rocky-shore intertidal molluscs were exploited intensively and frequently (possibly annually) from the site in the earlier Mesolithic (c6000-5200 cal BC).