Ancient weir sheds new light on Alaska Native history

Stone fish trap dates to at least 11,100 years ago, according to scientists.

By Jonson Kuhn

Seadrone photo showing stone fish trap found in Shakan Bay on the west side of Prince of Wales could potentially be oldest ever found in the world. The structure was first discovered in 2010 and officially confirmed as a stone weir earlier this year. (Courtesy Photo / Sealaska Heritage)

The watery depths near Prince of Wales Island recently revealed an Indigenous connection to Southeast Alaska even deeper than previously known.

A team of scientists discovered what could potentially be the world’s oldest stone fish weir in the Shakan Bay on the west side of Prince of Wales Island, which could mean Southeast Alaska Natives were living in the region at least 1,000 years earlier than previously confirmed, according to Sealaska Heritage Institute, a Juneau-based nonprofit that works to perpetuate Southeast Alaska Native cultures.

SHI President Rosita Worl said the discovery further substantiates the great antiquity of Alaska Native people in Southeast Alaska while also challenging preconceived thoughts on conditions required for civilizations of the past to advance and develop.

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“One of the things that I think isn’t spoken enough about is that anthropologists have always said that you have to have an agriculture before you could have civilization, but there is later thinking, and I support this, that complex societies can also emerge from maritime cultures and very definitely we had a rich environment,” Worl said. “So, I think the rich environment was the requisite that we needed and had to develop a very complex society and culture, which Northwest coast people do.”

The fish trap is thought to date to at least 11,100 years ago and this date was confirmed earlier this year by a group of university academics along with Sunfish Inc., a robotics company specializing in undersea exploration and inspection, according to SHI.

According to Worl, the age of the weir pushes back the date of Native presence in the Southeast Alaska region by more than 1,000 years. Worl also said that previous scientific studies have confirmed that Indigenous people lived in Southeast Alaska at least 10,000 years ago.

“The 10,000 date comes from when we had found ancestral human remains discovered in a cave on Prince of Wales Island called On Your Knees cave,” Worl said. “We did the DNA analysis and other scientific studies from that human remains and from that point in time the scientist came up with the 10,000 plus years age.”

Worl said the find suggests Native people occupied the area much longer than 11,100 years ago because it would have taken time for Indigenous people to learn enough about the environment and fish behavior before developing technology to make the weir and use it successfully.

“I would have to just do a best guess scenario based on learning about the environment years and the more recent period and I would probably say a couple hundred years,” Worl said. “It’s really hard to say, there is a suggestion that we’ll find earlier presents and that’s based on the sea levels and just kind of estimating from migrations that we’re assuming that we had a coastal migration, which is a newer theory. Prior to the coastal theory people thought that we came through the ice-free corridor but that would be much later. So, there has been growing evidence of coastal migration that I think this discovery further substantiates.”

Stone weirs, or tidal fish traps, were often seen as low arched walls made of boulders constructed across gullies, according to SHI. During high tides, the fish would swim over the stone walls and as the tide ebbed, the fish would then be trapped behind the walls, which would then allow for fishers to easily catch them in nets or with spears and other means.

Fish weirs were commonly used around the world in ancient times, and other stone weirs have been documented in Southeast Alaska, according to SHI, but this most recent discovery is said to be by far the oldest one ever found, and it is the first one ever confirmed underwater in North America.

Kelly Monteleone, an archaeologist at the University of Calgary, said that the structure was first found in 2010 by use of side-scan sonar technology, which detects and images objects on the seafloor. Monteleone said that while scientists suspected the image to be a stone weir, funding restraints held up the team’s ability to confirm their hypothesis until earlier this year.

“It was the first year of my Ph.D. when I found it, and when I was going through the sonar data, I found these semi circular low stone walls, so shadows, that fit very closely and so I thought possibly it was a weir,” Monteleone said. “We presented it to a conference and people were like, ‘Yes! That looks exactly like the weir structures in the area.’ So, I had lots of confirmation, but most people can’t really read sonar data, so with the program that I was in, we agreed that it was a possible weir. So, for the last 12 years this has been known as a possible weir and I’ve published about it and things along those lines but we’ve finally been able to get on it with eyes and confirm that it’s an actual weir. We can confirm that this isn’t just some random rocks on the seafloor or some artifact on the sonar data.”

Monteleone said that the reason for the delay in time from the structure’s first detection to its official confirmation was largely due to an error in relocating the structure along with a lack of funding.

“We actually went back in 2012 and looked for it, but we were a little off in 2012, we weren’t taking into account the lag between the boat’s GPS and where the sonar unit was, and I didn’t find out about that lag until 2014, the last year of the Gateway to the Americas project, and so by that point in the year we had no way to go back up Ketchikan Bay because the research project I’d been working on weren’t the full length of Prince of Wales Island usually and so getting from place to place is a large part of the project and we were working in the southern parts like the Gulf of Esquibel, so getting back up to Ketchikan Bay just wasn’t possible once we realized where the error was with that,” Monteleone said. “Then I finished my Ph.D. and as a new career researcher it’s hard to get funding, and the person I was working with, Jim Dixon, retired, so he hasn’t been trying to go back. So, this was my first source of funding and I’ve been writing in that I want to go back to this weir into every piece of applications that I’ve put together.”

Monteleone said the actual age of the weir was determined based on sea level reconstruction to be approximately 11,1000 years, but she anticipates that upon further investigation they’ll find evidence in Southeast Alaska that dates the structure to at least 16,000 years ago. Monteleone added that the plan in moving forward is to explore underwater caves within the same region.

“In Southeast Alaska, there’s been a ton of amazing finds in caves, and so we have sonar data to help narrow down where the caves are,” Monteleone said. “So, next year we’ll be going back with an agency called Sunfish Inc. and it will be going into any openings that we find and we have divers going in with it and we’re going to be able to find more data to help refine that sea level curve and more environmental data, so we’ll learn more about sea level change and sea level rise and we’re hoping that we find more archeology, considering the archeology that’s been found in caves already in Southeast Alaska from this time period.”

While this is an extraordinary discovery in a general sense, Monteleone emphasized the significance the discovery holds for Indigenous people in further understanding their longtime homes.

“I want to bring this back around to the Indigenous use of the area and what this means to them because I see myself as someone who can bring in the technology and skillset to help them learn more about their past,” Monteleone said.