Measuring biodiversity and the loss of indigenous landscapes in coastal Louisiana using airborne imagery and satellite data

ABSTRACT The Adams Bay site is a Native American monumental centre located in the Mississippi River Delta (MRD), a dynamic, geomorphic environment comprised of marshes, bayous, and rivers. The site itself was constructed approximately 600 to 800 years ago by Indigenous communities who are the ancestors of modern-day coastal communities. Earthen mounds at Adams Bay have disappeared over the past 70 years, and the last remaining mound at the site has almost completely eroded away over the past 10 years. This is an environment that is rapidly subsiding, eroding, and becoming inundated due to sea-level rise, and within this environment are hundreds of earthen and shell mounds. This study uses Sentinel-2 and National Agriculture Imagery Program data to document decadal changes to the landscape at Adams Bay and posits that mound-building had net positive impacts on biodiversity and vegetation in this marshy, deltaic environment. Sites like Adams Bay provide remarkable ecosystem services, enhancing the resilience of coastal ecosystems, and they must be studied and/or preserved before being lost to climatic and environmental forces. Finally, these sites are still incredibly significant to modern Indigenous communities who live in the coastal zone today, and additional resources need to be dedicated towards their conservation.