Assessing Climate Change Vulnerability of Indigenous Archaeological Sites with UAV Surveys

 

Acadia’s shorelines are home to twenty-four Indigenous archaeological sites, known as middens or shell heaps. Because they are mostly made of mollusk shells, these sites preserve stone tools, pottery, and animal bones that would otherwise dissolve in the region’s acidic soils, making shell heaps important holders of information about past environments and Wabanaki lifeways.

Rising sea levels and larger, more frequent storms put these important heritage spaces at considerable risk, and many are already eroded.

To face this challenge, Wabanaki communities and managers in Acadia need a better understanding of where and how fast coastal archaeological sites are eroding. Deirdre McGrath, a PhD student in anthropology and environmental policy working with Dr. Bonnie Newsom at the University of Maine, seeks to fill the information gap with the help of drone-mounted sensors. Working with Tribal Historic Preservation Officers and a drone pilot, McGrath will survey archaeological sites in Acadia. The resulting multispectral images can be compiled with detailed GPS data to create three-dimensional digital models to measure local erosion rates.

Sensors on the drones will be able to record calcium content in the surrounding soil, which McGrath believes will indicate the size of the shell heaps.

To ground-truth this hypothesis and monitor erosion directly, McGrath is working with Midden Minders, a citizen-science project. Volunteers will monitor sites in and around Acadia over the course of a year to measure shell heap erosion and record sea level rise and storm data, including tracks, frequency, severity, and timing.

There are thousands of shell mounds along the coast of what is now Maine, and many are also threatened by erosion. McGrath intends to share her research with Wabanaki communities and conservation land managers in and beyond Acadia, in order to inform decisions about how to protect Indigenous archaeological sites.