All  
Archaeologists Discover 3,800-Year-Old Underwater Vegetable Garden

Archaeologists Discover 3,800-Year-Old Underwater Vegetable Garden


Piece by piece, archaeologists are discovering evidence of creative engineering techniques practiced by innovative ancient peoples. One such example is making archaeological news headlines – the discovery of a 3800-year-old wetland garden in British Columbia, Canada. This interesting find provides the first direct archaeological evidence of nondomestic plant management in mid-to-late Holocene peoples of the Northwest Coast. It has also provided local First Nations people with a bittersweet connection to their ancient ancestors.

Humans have used a variety a means to manipulate the environment around them. Although some are certainly more destructive than others, the desire to modify the environment and enhance survival is an age-old tale. Countless innovative techniques that were used to aid humanity, while leaving little negative impact on nature, have been lost to modern society. However, the recent discovery in the Pitt Polder wetlands of British Columbia is providing new information on these kinds of activities.

As Live Science reports, archaeologists discovered 3,767 whole and fragmented wapato tubers in a man-made underwater garden. By using tightly-packed, uniformly-sized rocks to create a foundation, the people living in that area were able to stop the plants from growing too far underground, making harvesting easier.

This rock pavement discovered at the site would have made harvesting the wapato tubers much easier

This rock pavement discovered at the site would have made harvesting the wapato tubers much easier. ( Katzie Development Limited Partnership )

The site’s marshy environment also proved a great help for conservation. Some of the 3000-plus year old tubers were preserved so well that they even have their starchy insides. The wapato tubers were dark brown to black in color. Wooden tools were also preserved in the waterlogged site.

Wapato tubers (Sagittaria latifolia) , also known as duck-potato, broadleaf arrowhead, or Indian potato, are plants that grow in shallow wetlands. The report on the discovery in Science Advances explains that these plants “were a historically prized and heavily traded food resource for indigenous populations along the Fraser and Columbia rivers, including the Katzie. Typically harvested from October to February, wapato was an important source of dietary starch through the winter months.”

1918 drawing of a Broad-leaved Arrowhead, (Sagittaria latifolia) plant.

1918 drawing of a Broad-leaved Arrowhead, (Sagittaria latifolia) plant. ( Public Domain )

The excavations also provided evidence that the tubers were used as an economic or social resource. As the researchers wrote : “Close to 150 fire-hardened digging stick tips, several found embedded tip down in the pavement, demonstrate how the wapato tubers were harvested en masse.”

The report in Science Advances also shows the people living at the settlement near the wetland garden carefully monitored and engineered its hydrology to create an environment where the tubers thrived.

A: Sample of conserved wood digging stick tips. B: Ancient wapato tubers (preconservation) excavated from the wet-site garden area at the Pitt Polder wetlands.

A: Sample of conserved wood digging stick tips. B: Ancient wapato tubers (preconservation) excavated from the wet-site garden area at the Pitt Polder wetlands. ( Hoffmann et al .)

It is interesting to note that the human impact on the wetlands seemed to help the floral environment while the site was inhabited. Debbie Miller, who works with the archaeological consulting firm owned by the Katzie Nation, told News Network Archaeology that “the site soon acidified and dried up” after the inhabitants left it about 3,200 years ago. Sedimentary analysis backed up this belief.

Tanja Hoffmann of the Katzie Development Limited Partnership and Simon Fraser University in British Columbia led the excavation and analysis of the wapato tubers. She was joined by a crew of 90 people, many of whom members of the Katzie First Nation. Miller says that several young people were involved as well, who used the project “to better connect with their heritage.” She said:

Culturally we talked about what it meant to be in the earth with our ancestors and touching their lives. We’ve just walked in the house of the ancestors. It was for many, many of our people an absolute connection to their history, something that they couldn’t have gained in any other way.”

However, the project proved bittersweet for Miller and many others - the underwater garden was uncovered during roadwork, but was paved over when the excavations were complete.

Site location. The dotted line represents the approximate historic extent of the Pitt Polder wetlands.

Site location. The dotted line represents the approximate historic extent of the Pitt Polder wetlands. ( Hoffmann et al .)

Top Image: ‘ Water for Camp’ painting by Charles M. Russell. ( Public Domain ) Detail: Some of the wapato tubers found at the Pitt Polder wetlands site in British Columbia, Canada. ( Katzie Development Limited Partnership )

By Alicia McDermott

Register to become part of our active community, get updates, receive a monthly newsletter, and enjoy the benefits and rewards of our member point system OR just post your comment below as a Guest.

Next article