Darrin Lowery

Millennial-scale sustainability of the Chesapeake Bay Native American oyster fishery

Significance Oysters are important organisms in estuaries around the world, influencing water quality, constructing habitat, and providing food for humans and wildlife. Following over a century of overfishing, pollution, disease, and habitat degradation, oyster populations in the Chesapeake Bay and elsewhere have declined dramatically. Despite providing food for humans for millennia, we know little about Chesapeake Bay oyster populations prior to historical fishing in the late 1800s. Using fossil, archaeological, and modern biological data, we reconstruct changes in oyster size from the Pleistocene and prior to human harvest through prehistoric Native American occupation and modern times. These data demonstrate sustainability in the Native American oyster fishery, providing insight into the future management of oysters in the Chesapeake Bay and around the world. Estuaries around the world are in a state of decline following decades or more of overfishing, pollution, and climate change. Oysters (Ostreidae), ecosystem engineers in many estuaries, influence water quality, construct habitat, and provide food for humans and wildlife. In North America’s Chesapeake Bay, once-thriving eastern oyster (Crassostrea virginica) populations have declined dramatically, making their restoration and conservation extremely challenging. Here we present data on oyster size and human harvest from Chesapeake Bay archaeological sites spanning ∼3,500 y of Native American, colonial, and historical occupation. We compare oysters from archaeological sites with Pleistocene oyster reefs that existed before human harvest, modern oyster reefs, and other records of human oyster harvest from around the world. Native American fisheries were focused on nearshore oysters and were likely harvested at a rate that was sustainable over centuries to millennia, despite changing Holocene climatic conditions and sea-level rise. These data document resilience in oyster populations under long-term Native American harvest, sea-level rise, and climate change; provide context for managing modern oyster fisheries in the Chesapeake Bay and elsewhere around the world; and demonstrate an interdisciplinary approach that can be applied broadly to other fisheries.

New Evidence for a Possible Paleolithic Occupation of the Eastern North American Continental Shelf at the Last Glacial Maximum

Mastodon remains dated to 22,760 RCYBP were recovered with a bifacial laurel leaf knife from 250 ft below sea level on the outer continental shelf of Virginia. This chapter reports the results of our research concerning this find and an on-going survey of the extensive archaeological collections of the Smithsonian and other repositories including large private collections that are representative of the Chesapeake Bay drainage system. We located additional laurel leaf specimens recovered by watermen working on the continental shelf. The study indicates that these bifaces are not part of the post last glacial maximum (LGM) technologies and, therefore, support an LGM occupation of the continental shelf of North America.

Clovis Coastal Zone Width Variation: A Possible Solution for Early Paleoindian Population Disparity Along the Mid-Atlantic Coast, USA

ABSTRACT A coastal ecological model based on coastal zone width is presented to explain human interest in the coastal plain during the Clovis-era circa 13,200 to 12,800 years ago. Isobathic depths on the continental shelf along with relative sea-level data are used to approximate the Clovis-age coastal zone widths for the Delmarva Peninsula and coastal North Carolina. Coastal plain areas with former broad coastal zones during the Clovis-era have revealed large numbers of Clovis diagnostics within the extant terrestrial settings. In contrast, regions with narrow coastal zones during the Clovis-era imply limited use of the coastal plain. Modern analogues to these types of settings denote disproportionate coastal and marine resource productivity, which may explain the disparity of Clovis sites along the extant Atlantic coastal plain areas of the eastern United States.

ACCELERATOR MASS SPECTROMETRY 14 C DATING AND THE ANTIQUITY OF SHELL-TEMPERED CERAMICS FROM THE CHESAPEAKE BAY AND MIDDLE ATLANTIC

Abstract Ceramics typologies have long been used to build artifact, site, and regional chronologies. Direct accelerator mass spectrometry (AMS) 14C dating of shell-tempered ceramics offers a promising tool for updating and improving these chronologies. Few studies have 14C dated shell fragments from shell-tempered pottery, however, and questions remain about potential biases from “old shell,” the reservoir effect, and other variables. Forty-five direct AMS 14C assays on shell-tempered pottery and associated shell, charcoal, and bone from nine archaeological sites in Virginia and Maryland provide a framework to test this method. AMS 14C assays from one site may have problems with old shell, but most of the calibrated direct and associated age estimates overlap. One of our samples is the oldest securely dated shell-tempered pottery in North America at ~1000 cal B.C. Our study demonstrates the promise of AMS 14C dating shell-tempered pottery for refining ceramic and regional chronologies in coastal and other areas around the world.

Human Ecology and Coastal Foraging At Fishing Bay, Maryland, USA

Chesapeake Bay is the largest estuary in the United States and is famous for its once extensive and now severely degraded eastern oyster (Crassostrea virginica) populations, along with a number of other important fisheries including crabs, rockfish, and menhaden. Here we explore the historical ecology of Native American subsistence and land use strategies in the Fishing Bay area of Marylands Eastern Shore, building on our broader bay-wide analyses of oyster fisheries and human-environmental interactions. Archaeological analysis of faunal remains from shell middens dated between AD 500 to 1500, along with analysis of locally collected modern oysters, help reconstruct Fishing Bays evolution during the late Holocene, and document shellfish harvest strategies and predation pressure. These data suggest a stable and sustainable prehistoric oyster fishery in Fishing Bay, likely due to: 1) seasonal harvest and local consumption; 2) intertidal harvest that allowed replenishment from subtidal populations; and 3) relatively low human population densities. When placed in the context of our broader bay-wide analysis, these data provide implications for managing the present day oyster fishery, lending support to increasing no-take zones and expanding oyster sanctuaries that can be rotated with areas actively being fished.