Variability in late Holocene shellfish assemblages: the significance of large shore barnacles (Austromegabalanus cylindricus) in South African West Coast sites

The archaeological significance of barnacles has been documented in several places around the world, but this remains to be realised for South Africa. In the absence of local ethnographic observations, it was proposed that large barnacles (Austromegabalanus cylindricus) were taken to campsites attached to large black mussels (Choromytilus meridionalis) as part of scavenged beach-stranded fauna. Basic observations available until recently for South African West Coast shell middens showed that the presence of large shore barnacles is chronologically patterned. Some hints regarding transport decisions were also apparent. This paper examines the variability in large barnacle abundance through time and space using mollusc and crustacean shell samples from eight late Holocene sites situated at different distances from rocky shorelines. Modern knowledge on the ecology of collected species is used to interpret inter-assemblage variability. This study shows that barnacle abundance depends on at least three aspects, namely: the degree of wave exposure from which barnacles and other shellfish were collected, possible shifts in the main season of shellfish collection in the last 1700 years, and field processing before transporting shellfish loads to camps.