Indigenous peoples have harvested huge amounts of seafood without harming ecosystems

Eroding archaeological site on the east coast of Maryland.  Sites like this contain massive amounts of oysters harvested over 1,000 years ago and were key in forming the basis of this study.

Eroding archaeological site on the east coast of Maryland. Sites like this contain massive amounts of oysters harvested over 1,000 years ago and were key in forming the basis of this study.
Photo: Torben Rick

Before the arrival of European colonizers in the Americas and other parts of the world, indigenous peoples had been farming tons of seafood, especially oysters, the right way for millennia.

A new report in the magazine Nature Communication notes that the indigenous communities of the North American coasts and Australia have successfully harvested local oysters for several thousand years, without depleting shellfish populations or causing major damage to surrounding ecosystems. The researchers believe that learning more about Indigenous harvesting practices could help inform future oyster management systems.

Evidence of this is found in huge mounds of oyster shells on both coasts and in Australia. According to the study, the size of the mounds highlights that the communities harvesting the oysters were able to do so over long periods of time. A dump, as these mounds are called, is on Fig Island, South Carolina, and it contains about 75 million oyster shells; a site on the island of St. Helena in Australia contains around 50 million oyster shells that were probably harvested over 1,000 years.

Some of the oldest oyster middens studied in Massachusetts and California date back over 6,000 years, and some of the most used sites span around 5,000 years, providing evidence of the communities that lived in those areas.

Torben Rick, anthropologist Smithsonian National Museum of Natural Historysaid that this study was based in part on a 2004 paper which described the collapse of more than two dozen fisheries along the coasts of North America and the east coast of Australia. Rick pointed out that the study focused on commercial oyster fisheries that were founded after Europeans forcibly evicted indigenous communities. A post-colonial capitalist system failed to consider the sustainability and viability of future oysters to spawn when harvesting for profit.

“[Commercial harvesting] depletes an area – they start going down to a new area, so they go from the Boston Harbor area to New York, then to the Chesapeake Bay, then finally to Louisiana,” Rick told Earther.

Rick said the results of this study show how communities can consume animal products in a sustainable way, if done locally and if the ecosystems where the food is harvested are maintained. Far from modern commercial fishing which often relies on bottom trawling, a destructive technique that uses huge nets to drag everything up from the seabed, tearing up corals, oyster beds and sea plants that different animals need to thrive. Environmental groups have connected from bottom trawling to overfishingin particular because the method is not selective and the damage does not allow the marine environments to recover.

In contrast, the massive oyster mounds that exist in North America and Australia have proven that communities can sustain themselves partly on oysters and other seafood without depleting the environments they depend on. Researchers mapped information about Indigenous communities and their oyster harvest by carbon dating shell mounds, mapping oyster beds, and working with Indigenous partners to fill some community information gaps who created the shell middens.

“To provide context for these commercial fisheries, we needed to examine these archaeological records and work with Indigenous partners to understand what these fisheries were like and how they might help us make decisions in the future,” Rick said.

Bonnie Newson, an assistant professor of anthropology at the University of Maine and a citizen of the Penobscot Indian Nation, is a co-author of the study. She provided information on oral stories about indigenous communities and their connection to oysters. When asked why indigenous peoples were able to maintain mollusc populations, she replied: “I suspect it has to do with different views of how people view the species, different worldviews in terms of the relationship between humans and the species. There’s this notion of giving back to the species and dealing [them] respectfully. I don’t know if that extended to clams and oysters, but I certainly know it extended to things like salmon and other species here in Maine.

Newsom stressed that tribal nations should be part of future sustainability plans and maintain local food systems. “It’s not fair, ‘ok Iindigenous peoples…we kind of messed up this environment…now help us,” she said.

There have been recent efforts include tribal knowledge in Conservation efforts. In Northern California, the Yurok Tribe has contributed to efforts to revive wild condor populations by leading the release of two of the birds in their ancestral lands. Tribal members are also trying to revive wild salmon in the state.