The Archaeology and Historical Ecology of Small Scale Economies

5. Cumulative Actions and the Historical Ecology of Islands along the Georgia Coast

5 Cumulative Actions and the Historical Ecology of Islands along the Georgia Coast Victor D. Thompson, John A. Turck, and Chester B. DePratter They catch fish, gather shellfish, and build towns and villages on the strand and in small embayments. Their coastal activities have been so numerous and varied that their total effect has been significant. One of their most persistent activities has been the building of shell mounds, which are large piles chiefly of refuse resulting from various uses of shellfish. . . . they cover as much as 10 per cent of the shoreline. . . . these mounds have been instrumental both in holding the coast line against retrogression and in aiding progression. John Davis, “Influences of Man Upon Coast Lines” John Davis wrote the above words more than 50 years ago in a chapter in the seminal volume Man’s Role in Changing the Face of the Earth (Thomas 1956). A professor of botany at the University of Florida at the time of its publication, Davis considered shell mounding significant enough to include in his worldwide overview of the influence of humans on coastlines. Indeed, shell accumulations that are the products of human behavior, either in the form of intentionally mounded architecture or refuse remains, occur worldwide (e.g., Bailey and Milner 2002; Erlandson 2001; Thompson and Worth 2011). While great strides in understanding shell middens and mounds have been made in the latter part of the twentieth and early twenty-first centuries (e.g., Rick and Erlandson 2008; Fish et al., this volume ; Milner, this volume), we still do not fully understand the dynamic interaction between these structures in the context of human-environmental interactions in coastal environments (see Pennings, this volume). 80 · Victor D. Thompson, John A. Turck, and Chester B. DePratter The purpose of this chapter is to examine, in-depth, the role that preindustrial societies had in shaping coastal ecosystems and provide a preliminary case study of how small-scale economies, over time, work to transform environments (see also Rick, this volume; Milner, this volume). More specifically, we focus on the consumption and deposition of shellfish by hunter-gatherer-fishers of the southern Atlantic coast of Georgia, United States, over the past 4,500 years as a potential driving force in long-term coastal ecosystem dynamics. Historical ecology is the primary theoretical framework that structures our research along the Georgia coast. Specifically, we focus on two key aspects of historical ecology that set it apart from other frameworks. First, as defined by Balée and Erickson (2006:1,5), historical ecology takes the view that humans are a keystone species and thus a primary driver of ecological change, whether their actions are intentional or unintentional (see Balée 1998). Second, historical ecology focuses on the landscape, while also recognizing that a full understanding of the landscape is only possible by linking together multiple scales of analysis that range from the local to the regional level (Balée 1998; Balée and Erickson 2006:12; Crumley 1994b:10, 2007:16–17). Our central argument is that the deposition of shellfish fundamentally altered the ecosystem by both creating and modifying upland habitats. Specifically , we focus on small islands of upland habitat surrounded by marsh, located between the larger barrier islands and the mainland, known as marsh islands, back-barrier islands, or hammocks. These marsh islands should be characterized as “keystone structures” (Pennings et al. 2010), which are defined as “a distinct spatial structure providing resources, shelter , or ‘goods and services’ crucial for other species” (Tews et al. 2004:86). Thus, because humans played a critical role in the formation of many of these marsh islands, much of the coastal ecosystem of Georgia represents a distinctly anthropogenic landscape. We argue that these marsh islands comprised a considerable component of the overall economy of Native coastal societies (Thompson and Turck 2010). Further, we argue that, at least in terms of intensity of use, the hammocks and associated marsh are comparable to the larger barrier islands. Finally, we suggest, following island biogeography theory (MacArthur and Wilson 1967), due to the size and relative isolation of some of these islands, they are more susceptible to human impacts. To illustrate this argument, we provide a brief outline of the Native Cumulative Actions and Historical Ecology of Islands along the Georgia Coast · 81 American occupation of coastal Georgia. We then present a series of data at varying scales of analysis (e.g., regional site...