The effects of sampling on the analysis of archeological molluscan remains: A quantitative approach

Abstract

Sampling is a practice that affects all stages of archeological research, and is a method frequently employed to manage the potentially vast quantities of material recovered from excavations. Current sampling methods used in the analyses of shell middens are largely based on those developed by the California School, and can be characterized by the implementation of small sample sizes during the excavation and analysis of shell deposits. The wider archeological sampling literature, however, has repeatedly demonstrated that the use of small sample sizes has the potential to result in the loss of substantial quantities of material, often grossly underestimating an assemblage's richness, and skewing abundance distributions. There is therefore a need to re-evaluate the current sampling methods used in the analysis of shell deposits. We use five ecological diversity indices to examine and quantify the effects of sampling on the recovery and interpretation of molluscan remains, using material from the Peel Island Lazaret Midden, southeast Queensland, as a case study. This research demonstrates that the use of small sample sizes does indeed affect measures of richness and evenness for molluscan populations, with marked differences being recorded for the two sample sizes used in this study. Results show that while subsamples are able to detect some trends in taxonomic richness and evenness, the degree of difference present between the results from the two sample size indicates that subsamples reduce interpretive accuracy. We conclude that, in addition to determining the appropriate sampling strategy during excavation or recovery of midden deposits as highlighted by previous research, there is also a need for researchers to assess sampling practices during the analyses of molluscan assemblages. The methods employed in this study can be easily applied and offer a robust means of determining the effects and adequacy of sampling.