According to a study published in May in Nature Communication.

The study authors examined ancient oyster fisheries on the Atlantic and Pacific coasts of North America and eastern Australia and found evidence of intensive oyster harvesting dating back to over six thousand years in some areas. These oyster fisheries emerged after sea levels stabilized after the end of the last ice age, when the estuaries on which many oyster species depend were established.

“An interesting finding from this study is that many places on the coast have had stable oyster populations for thousands of years. As we work to restore this species, this data can help determine where restoration needs to take place. take place,” says Marco Hatch, associate professor of environmental science at Western Washington University and author of the study.

“Rather than relying on models and assumptions about where oysters might thrive, we can use thousands of years of data to guide restoration efforts,” adds Hatch, who is also a member of the Samish Indian nation, whose territory covers the central and southern San Juan Islands in Washington State.

That such a discovery only now appeared in a scientific journal is no coincidence. Indigenous traditional knowledge, developed through observation of communities over thousands of years, has long been considered less reliable than modern science because it is seen as “anecdotal” or “imprecise” when it appears to question scientific “truths”. have sometimes been viewed by non-Indigenous scholars as “wilderness areas” that ironically need to be protected from the Indigenous peoples who have shaped and managed these landscapes for millennia.

“Until recently, many scientists perceived indigenous peoples as having a very ‘light’ footprint on their landscape and, living in such small communities, they had minimal impact on their environment,” says Leslie Reeder-Myers , assistant professor of anthropology at Temple University and author of the study. “This document shows that this is a false impression – indigenous peoples in some areas harvested billions of oysters from one location.

“Their light footprint, even if it existed, was not due to people but to landscape management practices. This is of growing interest to many ecologists, and the study of traditional knowledge or local knowledge has become much more widespread in recent times.

Besides being a delicacy, oysters, when aggregated naturally in the reefs, also clean the local water and prevent coastal erosion. Yet an estimated 85% of oyster reefs have disappeared worldwide due to overexploitation, land development, pollution, disease and other factors. “Even a good harvest today is only a fraction of what it was a few hundred years ago,” says Reeder-Myers.

The Nature Communication The study found that instead of coastlines being ‘pristine’ or untouched by people, they were in fact sustainably managed landscapes. As an example, the research cited a technique still used by the Quandamooka Aborigines living today in Australia’s Moreton Bay, who use old oyster shells to build artificial reefs to raise young oysters that are used to repopulate depleted reefs and thus extend the seasonal availability of shellfish.

In addition to examining sea level data and historical accounts of oyster harvests, the researchers also studied shell middens – archaeological sites where shells were discarded after shellfish consumption – to assess the intensity of oyster consumption in a region, as well as the relationship of oysters with Aboriginal people. peoples’ culture and society.

Some shell middens have been found to have ritual or ceremonial significance: a massive shell mound in San Francisco Bay dating back 6,000 years contains burials, and a mound on the Gulf Coast of Florida that once contained perhaps 30 million oyster shells was flattened at the top to form a platform for ritual activities.

But these sustainable fisheries collapsed soon after the colonization of indigenous peoples by European settlers due to overexploitation, pollution and other developments. In one example cited by the study, 1.1 billion pounds of oysters (or 1.7 billion individual oysters) from the Chesapeake Bay were harvested in one year in the 1890s alone. But these unsustainable harvests caused production to decline over time, down to just a few million pounds in the 1990s.

“It’s important to recognize the connections between environmental justice and conservation biology,” says Torben Rick, curator of North American archeology at the Smithsonian Institution’s National Museum of Natural History and author of the study. “There are direct links between colonial atrocities committed against Indigenous peoples and the subsequent degradation of marine and terrestrial ecosystems.

Although much damage has already been done, efforts are currently underway in some places to restore ancient fisheries. Around the Chesapeake Bay, restoration initiatives have been introduced in several rivers, with some water filtering benefits already visible.

“There are signs that some fisheries are recovering – although not to historic abundance – but climate change and other processes pose significant challenges, and we need concerted efforts to ensure the sustainability of oysters in the future. ‘future,’ says Rick.

The authors of the study recommended that the management of the oyster fishery involve indigenous communities, for example by applying more traditional knowledge in research and by involving indigenous peoples in management processes, until the implementation of side of the oyster fishing areas for their direct management. In addition to boosting oyster harvests, such efforts could be a step in returning stewardship of the land to groups who have lived there for millennia.

“Archaeology can show the depth of Indigenous connections to ecosystems and the scale and intensity of ancient fisheries,” says Reeder-Myers, “but there is no need to extract Indigenous knowledge from the past when we can simply include indigenous peoples and their knowledge in the present.

“There are descendants of these people alive today – some of them helped write this article. As damaged as these fisheries are, they still represent the ecological heritage of people who were forcibly removed from these areas in the past. If we continue to make the decision to exclude them, we continue to practice colonialism”.