A new study reveals a bright spot for shellfish populations in the northeast Pacific Ocean. Combining paleontological tools and archaeological data with conservation research, the paper finds that, for the past 3,000 years, crab and clam species have remained stable in the Broken Group Islands off the west coast of Vancouver Island, British Columbia.
The results, published in the July 2025 issue of Biological Conservation, suggest that the area has been largely sheltered from large-scale commercialization during the past century—while also demonstrating the sustainable relationship between local Indigenous peoples and shellfish over millennia.
“We always think of ourselves as separate from nature, but we are a part of our ecosystems,” says Kristina Barclay, a research scientist at the Hakai Institute who was the lead author on the study. “Indigenous peoples understand this inherently, and the archaeological record can also demonstrate that.”
Dungeness crab is one species of cultural importance to coastal First Nations, and the study—which Barclay conducted as part of a Banting Postdoctoral Fellowship at the University of Victoria (UVic), in collaboration with UVic researchers Julia Baum and Iain McKechnie as well as a Tseshaht First Nation representative, Denis St. Claire—finds that crab populations in the Broken Group have remained stable over thousands of years of harvesting. Crabs such as Dungeness have been largely overlooked in the archaeological record, despite concerns from First Nations on the central coast and other parts of British Columbia about species declines.
The paper takes a novel approach to studying the abundance of crabs and clams: it looks at evidence of crab predation efforts by Dungeness, red rock, and graceful rock crabs on littleneck and butter clams. When a crab attacks but fails to kill, it leaves a claw-shaped “repair scar” on the clam shell, “just like if you’ve healed from a broken bone,” Barclay says.
Repair scars have been used to assess the relative abundance of crab populations in modern contexts, but this is one of the first studies to consider scars as archaeological evidence of historical crab populations. For coastal First Nations and fisheries managers, this approach offers “one more tool in the tool box,” Barclay says, which could be applied more broadly on the BC coast, especially given the large number of archaeological sites.
“The approach was originally developed to study predator-prey interactions in the fossil record and predator-prey evolution through time,” Barclay adds. “It’s really cool to apply it to other fields.”
The fact that the Broken Group Islands are a stronghold for shellfish populations may not come as a surprise; the archipelago is located within Tseshaht First Nation territories and Pacific Rim National Park Reserve and is only accessible by boat, thereby sheltering the region from the kind of commercial harvesting that’s devastated populations elsewhere. But Barclay says she was surprised that ocean acidification and warming ocean temperatures due to climate change haven’t yet made a bigger dent in the Broken Group.
“I was expecting more of a sad story and was very happy to see that these populations are resilient,” Barclay says.
But just because it’s a good news story now doesn’t mean things aren’t tenuous, she adds.
“These ecosystems are still vulnerable to climate change, so we still really need conservation and to cut carbon emissions.”
Contact
Kristina Barclay
Research Scientist, Hakai Institute
(780) 278-3773
kristina.barclay@hakai.org
Media Kit
Download the media kit that includes this press release, the newly published paper, and photos with captions.
About the Paper
“Merging coastal archaeology and conservation paleobiology to evaluate shellfish resilience to Indigenous harvest over the past 3000 years” was published in the July 2025 issue of Biological Conservation.
Barclay, K.M., Baum, J.K., St. Claire, D., McKechnie, I., (2025). Merging coastal archaeology and conservation paleobiology to evaluate shellfish resilience to Indigenous harvest over the past 3000 years. Biological Conservation, 307, 111186.
https://doi.org/10.1016/j.biocon.2025.111186
About the Partners
University of Victoria
The University of Victoria is a leading research-intensive institution, offering transformative, hands-on learning opportunities to more than 22,000 students on the beautiful coast of British Columbia. As a hub of groundbreaking research, UVic faculty, staff and students are making a significant impact on issues addressing challenges that matter to people, places and the planet. UVic consistently publishes a higher proportion of research based on international collaborations than any other university in North America. Our commitment to advancing climate action, addressing social determinants of health, and supporting Indigenous reconciliation and revitalization is making a difference—from scientific and business breakthroughs to cultural and creative achievements. Learn more at www.uvic.ca.
Hakai Institute
The Hakai Institute, part of the Tula Foundation, is a British Columbia–based scientific institution dedicated to advancing science on the coastal margin. Hakai pursues its mission from ice fields to oceans, leveraging its ecological observatories and other strategic locations on the province’s coast. The Hakai Institute partners with universities, NGOs, First Nations, government agencies, businesses, and local communities to move the needle on advancing long-term coastal research. Learn more at www.hakai.org.
Tula Foundation
The Tula Foundation is a British Columbia–based organization that harnesses science and technology to tackle urgent global issues. Tula takes a comprehensive approach to these challenges, from coastal biodiversity and public health to data management and mobilization. Along with rural healthcare in Guatemala, Tula’s work drives pivotal action for coastal conservation and ocean research in British Columbia and beyond. Learn more at www.tula.org.
