When Climate Hit Native American Shell-Ring Villages

Shell-ring archaeological sites, “one of the most visible site types along the lower South Atlantic Coast of the United States”, are the subject of an interesting new study. The study reveals that these settlements represent the earliest known year-round Native American communities in the Eastern Woodlands, thriving in dynamic and shifting coastal environments.

Arc-Shaped Patterns: A Fluctuating Coastal Environment

These formations which take on circular or arc-shaped patterns, are composed mainly of mollusk shells, particularly from Crassostrea virginica (Eastern oyster), also including early pottery, animal remains, and other artifacts, reveals the study published in the newest edition of Scientific Reports.

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It is believed that these shell deposits accumulated around and beside homes, gradually forming ring-shaped middens as a result of both daily domestic activities and ceremonial feasting practices over time.

Through the use of sea-level modeling and isotope geochemistry analysis of mollusk remains, archaeologists have determined that these communities date back to around 5000–3800 years ago.

“They lived within a fluctuating coastal environment, harvested certain resources year-round, and targeted diverse habitats across the estuaries. Both the growth and decline of these earliest villages are associated with a concomitant rise and lowering of sea level that impacted the productivity of the oyster reef fishery along the South Atlantic Coast. Despite these large-scale environmental changes, this research indicates that Native American fishing villages persisted along the coast for over 1000 years,” write the authors of the study.

The study suggests that mollusk collection was likely tied to longstanding traditions, with particular groups or kin-based networks controlling access to specific harvesting areas. These ownership and management practices may have played a role in the sustainable use of these resources, particularly in light of fluctuating environmental conditions.

Sewee Shell Ring, located south of Awendaw, South Carolina in Francis Marion National Forest. Detail of southeast side, showing shells of which ring is made. (Ammodramus/CC0)

“Our study not only underscores the kinds of data needed to understand such complex human relationships but also provides insight into how this process of settling down occurred in North America and its attendant challenges in crafting a sustainable way of life for the Indigenous people of the region,” explained the authors.

The Role of Climate: Not Just a Modern Phenomenon

In fact, just two years ago, another study published in PLOS One indicated the role of climate change in a similar fashion. The researchers proposed that around 4300 years ago, as environmental changes began to impact oyster harvesting, communities came together to establish shell-ring villages, allowing them to better manage fisheries in response to shifting climate conditions.

However, after several generations, as further environmental changes occurred and oyster populations declined, these Native American groups eventually abandoned the shell-ring villages. They transitioned to a way of life that relied less heavily on seafood and adapted to new subsistence strategies.

The research also indicates that while oysters were harvested year-round, they were primarily collected during the colder months, while clams were gathered more consistently throughout the year, explains a report by Inverse.

Sewee Shell Ring, located south of Awendaw, South Carolina in Francis Marion National Forest, USA. (Public Domain)

The study also links environmental changes, especially wetter conditions that altered the salinity of the water—to fluctuations in oyster size over time. These findings support earlier research suggesting that Native Americans harvested oysters sustainably for thousands of years, countering the popular belief that unsustainable human practices were to blame for damaging oyster populations during this period.

The researchers tracked changes in oyster size, noting that healthier ocean reefs typically yield larger oysters. Since both human harvesting and environmental factors can influence oyster growth, the variations in size offer insights into past climate conditions and human activities, explained the same study.

Even as Native American communities developed strong cultural connections to the region, they demonstrated a remarkable ability to adapt to changing environmental conditions. According to the researchers, this adaptability allowed them to continue inhabiting these coastal areas for millennia, relying on knowledge passed down through generations to navigate shifting circumstances.

Top image: Aerial photograph of Fig Island Ring II off the coast of South Carolina, which currently is being inundated by sea-level rise.         Source: Photo and permission under CC BY by A. J. Koelker, Principal, Koelker & Associates, LLC/Nature

By Sahir Pandey