Intensification of shellfish exploitation: evidence of species-specific deviation from traditional expectations

As modern humans grapple with the repercussions of their extensive environmental impacts, archaeologists are increasingly looking toward the past to understand the nature and extent of prehistoric human impact on the environment. Many researchers rely heavily on archaeological correlates of resource intensification as a proxy measures of resource depletion, a profound and often catastrophic human impact. However, the traditional conceptualization of the archaeological correlates of shellfish intensification disregards a large amount of species-specific variation. This paper presents archaeomalacological data from Santa Cruz Island, California. The shell midden deposits CA-SCRI-480 contain a high density of Tivela stultorum (Pismo clam). Statistical analysis of the shellfish assemblage reveals significant variation in both the size and quantity of Pismo clam that people collected through time. This paper investigates this unique patterning with due consideration of the natural ecology and life history of the species and illustrates species-specific deviation from the traditional archaeological correlates of shellfish intensification. Increased collaboration with ecologists and biologists can help refine models of intensification when necessary in order create more sophisticated understanding of prehistoric human–resource interactions.

► Archaeological correlates of shellfish intensification.
► Analysis of shell midden assemblage from Santa Cruz Island, California.
► Pismo clam shell size increases through time and Pismo clam shell quantity decreases.
► Reverse of expected archaeological correlates for intensification.
► Indices of intensification vary with ecological and biological attributes of prey species.