Ancient Shellfish Mariculture on the Northwest Coast of North America

Abstract

While there is increasing recognition among archaeologists of the extent to which non-agricultural societies have managed their terrestrial ecosystems, the traditional management of marine ecosystems has largely been ignored. In this paper, we bring together Indigenous ecological knowledge, coastal geomorphological observations, and archaeological data to document how Northwest Coast First Nations cultivated clams to maintain and increase productivity. We focus on “clam gardens,” walled intertidal terraces constructed to increase bivalve habitat and productivity. Our survey and excavations of clam gardens in four locations in British Columbia provide insights into the ecological and social context, morphology, construction, and first reported ages of these features. These data demonstrate the extent of traditional maricultural systems among coastal First Nations and, coupled with previously collected information on terrestrial management, challenge us to broaden our definition of “forager” as applied to Northwest Coast peoples. This study also highlights the value of combining diverse kinds of knowledge, including archaeological data, to understand the social and ecological contexts of traditional management systems.

Ancient clam gardens, traditional management portfolios, and the resilience of coupled human-ocean systems

“…Among the Heiltsuk First Nation, the impact of harvests were also limited by restricting access to productive gathering sites based on family lineages (Powell 2012). Ancient clam gardens, a newly documented form of ancient mariculture technology (Harper et al 1995, Williams 2006, Groesbeck et al 2014, Lepofsky et al 2015, may have been the basis for yet another form of ancient resource management embedded within a portfolio of coastal management practices.…”

“…It is hypothesized that these rock walls transformed naturally sloping clam beaches into more levelled terraces through a combination of natural sedimentation (Harper 2007) and the active addition of gravel and shell hash by people (Groesbeck et al 2014). Similar to other resource management features and systems, clam gardens were embedded within a broader set of governance rules that guided management and use of associated land and seascapes (Lepofsky and Caldwell 2013, Deur et al 2015, Lepofsky et al 2015.…”

“…Written information on clam garden antiquity, ecological function, use, and management is just now accumulating (Williams 2006, Groesbeck et al 2014, Deur et al 2015, Lepofsky et al 2015 and builds on the traditional knowledge held by First Nations people (Deur et al 2015, Lepofsky et al 2015. Recent archaeological excavations in southern British Columbia indicate that clam gardens date to at least 1000 years Before Present (B.P.…”

“…Recent archaeological excavations in southern British Columbia indicate that clam gardens date to at least 1000 years Before Present (B.P. ; Lepofsky et al 2015). Observational and transplant experiments comparing clam gardens and nonwalled beaches have demonstrated that clam gardens, by flattening the slope of the beach, expand clam habitat at the tidal height at which clams grow and survive best (Groesbeck et al 2014).…”

Values-led management: the guidance of place-based values in environmental relationships of the past, present, and future

“…aspx), a millennia-old, place-based, and values-led approach to aquaculture supporting ecological and human well-being (Groesbeck et al 2014, Augustine and Dearden 2014, Lepofsky et al 2015, Jackley et al 2016) Tla-o-qui-aht Tribal Park, British Columbia, Canada Park design and implementation is guided by Tla-o-qui-aht values and priorities independently of colonial institutions, "as a projection of sovereignty over contested terrain, or an assertion of Tla-o-qui-aht rights and title" (Murray and King 2012:389). Whereas some outcomes of this tribal park might converge on the ecological protection sought through existing protected areas, it differs in being guided by the Tla-o-qui-aht worldview which, for example, sees the people as key components of the social-ecological integrity of the area (as in Berkes 2012 coastal and marine areas.…”