Indigenous oyster fisheries were ‘fundamentally different’: Q&A with researcher Marco Hatch

In the 18th century, when European ships sailed into the Strait of Juan de Fuca on the Northwest coast of the Pacific Ocean, they raved about the “wilderness” of the coast. The enormous natural wealth they saw—the wood from forests and the fur on animals—lured them into setting up a flourishing trade that would last centuries and script a new chapter in history.

The visitors thought the coast as pristine and untouched by humans. However, it was home to many Indigenous peoples, including the Nuu-chah-nulth, Makah, Salish, Kwakwaka’wakw and Haida peoples. These communities along the salty coasts lived here for thousands of years and stewarded the lands and ocean based on a relationship with nature rooted in reciprocity and traditional knowledge. Within a few decades, the intense trade that flourished on these lands uprooted this intricate human-nature relationship, and gave way to the commercialization of natural resources, including fisheries.

In the last 300 years, commercial fisheries have decimated many marine species across the world, including oysters. The Earth has lost about 85% of its oyster reefs since the 19th century due to overfishing, marine pollution, competition with other non-native species and habitat loss.

A landmark 2004 study, published in the Proceedings of the National Academy of Sciences, traced the expansion and collapse of 28 oyster fisheries along the coasts of North America and Australia since European commercial oyster fisheries started. It found an interesting pattern for the first time: In all these regions, the collapse began in the estuaries nearest to an urban center and expanded along the coast as each successive estuary became overfished.

Oysters from more distant estuaries were fished and transported to restock exploited estuaries near the urban center. But, prior to this commercialization, the scene of oyster fisheries under Indigenous management was very different.

Now, a new study, published in Nature Communications, studied the same sites and found that Indigenous communities in North America and Australia sustainably managed oyster fisheries for more than 5,000 years.

The researchers put together historical sea level data and derived oyster catch records using evidence from archaeological records of oyster middens (heaps of oyster shells). They found oyster fisheries thrived better in these regions than under the European settlers’ management of commercial oyster fisheries. With millions, and sometimes billions of shells harvested, some middens were as tall as 30 feet (about 9 meters), and served as important ceremonial, sacred and symbolic spaces.

Despite the bounty, large-scale depletion or declines of oysters were rare and localized due to traditional knowledge of harvest practices, consumption patterns and farming technologies.

The knowledge of these traditional practices can guide sustainable fisheries management today, say the authors.

“Conservation today can’t just be seen as a biological question and can’t just be about undoing the environmental damage we’ve done in the modern era,” explained lead author Dr. Torben C. Rick from the National Museum of Natural History, Smithsonian Institution, USA, in a press release.

“Instead, global conservation efforts should be coupled with undoing the legacies of colonialism which brought about the attempted erasure and displacement of Indigenous people all over the world,” he continued.