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 long-term 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 ecology context. Here, we examine that transition in the BC clam fishery, documenting the social and legal mechanisms used to dispossess Indigenous clam harvesters and identifying the ecological impacts of settler-colonial fisheries. Our results document a rapid change in clam tending, harvesting and processing that relied on Indigenous land, knowledge, labour and skill being directed away from traditional harvesting and towards unsustainable catches for commercial gain. We identify evidence of serial depletions and declines in relative abundance as measured by spatial shifts in harvesting, declines in catch per unit of effort, and a transition from native to non-native clam species. Finally, we identify additional evidence of the legacy of Indigenous tending 50 years after the start of the commercial fishery, demonstrating sustained productivity on beaches that continued to undergo Indigenous harvesting. Ongoing efforts in BC aim to restore ancestral clam beaches and tending practices. Historical insights can play a crucial role in restoration efforts by identifying ecological baselines and helping support the Indigenous reclamation of ocean spaces and the responsibility to tend them.This article is part of the theme issue 'Shifting seas: understanding deep-time human impacts on marine ecosystems'.