An Analysis of Marine Mollusk Exploitation at Río Chico, Ecuador

Abstract

Humans have long been exploiting marine resources, a subsistence practice that is thought to be an important part of the overarching evolution of modern humans. This project examines the shell remains from two temporal periods at Río Chico, a coastal archaeological site in Southern Ecuador. The collections are housed in the Salango Research Center, which in addition supplied a shell comparative collection that was utilized for identification purposes. A component of the archaeological collections is from the Valdivia cultural settlement, 4th millennium BCE; it is representative of one of the oldest cultural periods recognized along coastal Ecuador. An additional component is from the Guangala cultural period, 1st millennium BCE into 1st millennium CE, representing a phase in Ecuador's history that underwent significant cultural transformations. The data collected analyzes foraging patterns over time, to investigate the resource exploitation habitats and strategies employed by the Río Chico population, ranging from the intertidal zones to the deep sea. This analysis is interpreted through the theoretical lens of Optimal Foraging Theory (OTF), a biological framework that is often used within dietary studies. One of the shellfish represented in the collection is Spondylus, which was a coveted resource both for consumption and as a trade good. Spondylus is found in deep waters, and specialized diving skills are required to retrieve it. Archaeological evidence suggests that deep diving for Spondylus began in Ecuador around 3000 BCE, about 500 years before the initial occupation of Río Chico, and it has been previously recorded in all cultural periods at Río Chico. The results gathered by this shell analysis indicate that taxa from intertidal families such as limpets and chiton maintain a steady importance, while the presence of Spondylus increases through time. Such shifts in the exploitation of Mollusca indicate changes in foraging strategies from the Valdivia and Guangala cultural phases, especially concerning the increased risk of retrieving deeper water species. The results of this investigation will enable future research into shell remains from comparable contexts in coastal Ecuador and beyond, applying it to studies on: coastal foraging communities, overexploitation, community resource management, climate change, systematic trade of marine resources through history, and the interconnections of communities linked by Spondylus exchange systems.