Shell on Earth: Oyster Harvesting, Consumption, and Deposition Practices in the Powhatan Chesapeake

Abstract

Archaeological studies of North American shell middens have recently highlighted Native societies’ impacts on marine and estuarine waterscapes. Middens containing deposits of oyster shell (Crassostrea virginica) reveal histories of subsistence, settlement mobility, resource decline, and the long-term sustainability of fisheries. In this case study, we bring to the fore another important aspect of precolonial oyster exploitation: the habitat from which oysters were harvested. Five morphological attributes are measured to indicate whether Native fishers harvested oysters from nearshore or offshore habitats. Once combined with the archaeological context in which oyster shell was deposited, knowledge of harvesting location offers an avenue for considering social practice, the array of activities and pathways through which Native societies made and transformed the worlds in which they lived. In order to demonstrate the interpretive potential of this line of inquiry, we offer a comparative analysis of oyster shells from two contexts at Kiskiak, a Powhatan town in Tidewater Virginia. We hypothesize that Kiskiak fishers harvested large quantities of oysters from nearshore habitats and limited numbers of oysters from offshore reefs, casting light on social practices contributing to the oyster fishery’s sustainability on a millennial timescale.

Keywords:

• Shell middens
• social practice
• sustainability
• Chesapeake
• Powhatan

Notes

1 OxCal 4.3’s deposition models incorporate the relative depths of radiocarbon assays in a stratigraphic sequence to interpret the calibrated date ranges of deposits. The OxCal tool used to generate the Kiskiak midden chronology, the Poisson-process sequence (P_Sequence), models dates in a sequence with fluctuating rates of deposition. As depicted in Figure 5, the chronological model for the Kiskiak midden includes boundaries around a deposit with a higher density of shell within the midden since deposition rates in this zone likely differed from those above and below.

2 While the difference was relatively modest, it was statistically significant, based on non-parametric comparison of period (an ordinal-scale variable) and oyster height (n = 1052; Kendall’s τ = 0.05, two-tailed p = .037; Spearman’s ρ = 0.067, two-tailed p = 0.038).

3 Based on a one-way ANOVA comparing Middle Woodland I, Middle Woodland II, and Late Woodland I shell heights (n = 621, F = 3.812, df = 2, p = 0.023).

4 An Independent Samples t-test indicates that the difference between the Middle Woodland II and Late Woodland I mean approaches significance at the 0.05 level (t = 1.948, df = 164, p = 0.053).

5 Dividing 200,000,000 oysters by 1,400 years, and then again by 26 weeks.

6 Twenty billion oysters equals 200 million times 100. Twenty billion oysters divided by 1,400 years equals approximately 14,300,000 oysters per year. Assuming that there are 100 oysters per bushel (an industry standard), the Powhatans harvested roughly 143,000 bushels per year. Of course, this number is far from precise. The Powhatan region constitutes roughly half of the portion of the Chesapeake estuary that supports oysters, so the calculations likely underestimate the overall Chesapeake harvest by a factor of two. On the other hand, Powhatan settlements in the interior Coastal Plain did not have ready access to the waterways with salinity levels supporting oysters, meaning that the estimate may be too high if restricted to the Powhatans alone. Given the complexities of both the cultural landscape and of the ecological setting, we offer this estimate as a simple starting point for considering the conservation paleobiology of the Chesapeake oyster.