Supplementary material from "Ecological legacy of Indigenous dispossession: Disruption of ancestral sea gardens by commercial clam fisheries in British Columbia, 1882-1985"

Ancestral sea gardens in British Columbia (BC) were managed to provide high yields for millennia before European contact. While the ubiquity and productivity of sea gardens are well known, the ecological and cultural impact of the transition from ancestral to settler-colonial fisheries has not been investigated in a historical context. Here, we examine that transition in the BC clam fishery, documenting the social and legal mechanisms used to dispossess Indigenous harvesters and the ecological impacts of settler-colonial fisheries. Our results show a rapid changes in clam tending, harvesting, and processing, relying on Indigenous land, knowledge, labour, being redirected from traditional use toward unsustainable catches for commercial gain. We identify evidence of serial depletion and declining abundance, measured by spatial shifts in harvesting, reduced catch per unit effort, and a shift from native to non-native clam species. Finally, we find additional evidence of the legacy of Indigenous tending fifty years after the commercial fishery began, with sustained productivity on beaches that continued to be harvested by Indigenous communities. Ongoing efforts in BC aim to restore ancestral clam beaches and practices. Historical insights play a crucial role in restoration by identifying ecological baselines and supporting Indigenous reclamation of ocean spaces and responsibilities.