Memories of fishers reach beyond the data
Catch recollection of Brazilian fishers provide accurate reconstructions of fisheries counts in remote regions.
On the coast of Brazil, generations of fishers have set out every day to fish for food that will provide a livelihood for their families and communities. Now, with increased fishing and declining fisheries stocks raising concerns about future access, there is a critical need to understand historical harvest totals in rural regions to gain a better picture of what a robust ecosystem would look like.
A research team led by College of Natural Resources and Environment Associate Professor Leandro Castello is turning to an unusual source to accomplish this goal: the memories of fishers who have made their livings harvesting the world’s oceans and rivers. A new paper published in Frontiers in Ecology and the Environment suggests that local knowledge of past harvests can provide an accurate – and affordable – depiction of historical fish stocks. Additionally, having community fishers participate in developing stock quota histories has the potential to increase participation in future conservation practices and approaches.
This research aligns with Virginia Tech’s pledge to address global challenges through extensive, diverse partnerships and interdisciplinary collaborations, a hallmark of the Virginia Tech Global Distinction commitment to elevate the university’s international efforts to act as a force for positive change.
Collecting data face-to-face
Funded by the Pew Charitable Trust, the first step of Castello’s research team was selecting regions in Brazil where there was robust scientific data on fishing hauls. With that data on hand, researchers conducted interviews with area fishers to see if their memories aligned with the available data.
“All in all, we were able to compile data from nearly 400 fishers from 24 coastal fisheries in Brazil,” said Castello, who teaches in the Department of Fish and Wildlife Conservation. “These are communities where they are harvesting sardines, mahi-mahi, and other fish species.
“On average, we found that the fishers were about 95 percent accurate,” said Castello, an affiliated faculty member of the Fralin Life Sciences Institute, the Global Change Center, and the Center for Coastal Studies. “What this research does is get at the concept of the wisdom of the crowd. We’re able to demonstrate that you can produce information that is useful in reconstructing the historical record at a fraction of the cost of trying to rely on large-scale fisheries data.”
This knowledge fills a crucial gap for researchers attempting to determine fisheries declines in regions where broadscale data currently is not being collected. While individual accounts of fish catch are invariable scattered, when a large enough sample is aggregated, the result is data that can accurately depict the extent of fisheries harvest declines going back nearly 50 years.
Local knowledge as a tool for change
This project was not the first time Castello utilized local knowledge to conduct fisheries research: He has an extensive research portfolio studying arapaima, a species of air-breathing river fish that is a critical resource for communities along the Amazon. He also has conducted catch assessment research on Congo River fisheries where there is little collected fisheries data.
“My research on arapaima in the Amazon and in the Congo shows that fishers can produce useful fish data just as well as the best scientific methods with two differences: The fishers are 200 times cheaper and they are much, much faster at providing data,” said Castello.
And there is a third benefit: Involving fishers directly in the process gives them a stake in trying to conserve declining fishing stocks.
“With this paper, we’re able to go back to these communities and show them the graphs,” said Castello. “In another context, one could even point out each of their names as data points. In our work in the Democratic Republic of Congo, we recently shared our findings and said, ‘This is the information you gave us and this is the statistical method we used. Do you question these results?’ When they said no, we asked if there was anything they wanted to do about these declines.”
The fishers – not merely the subject of research but participants and experts – expressed a greater willingness to consider conservation approaches that would protect fish stocks for future seasons and generations. For Castello, getting such buy-in is critical to promoting real change, because it aligns local communities with the global challenges of conserving fishing stocks in the world.
“Having cheaper access to data is important, but the more vital part of this research is giving rural communities the tools and the responsibilities to manage their resources,” Castello said. “The key difference with this approach is that we’re relying on the skills and knowledge of the fishers and not just coming in with fancy scientific information and results that have nothing to do with their lives.”
Castello recently presented on this research to policymakers in Brazil’s federally protected areas, who are considering pilot programs to incorporate fishers’ memories in strategies to improve fisheries management in the country.
Castello’s collaborators within Virginia Tech include Michael Sorice of the Department of Forest Resources and Environmental Conservation and Eric Smith of the Department of Statistics. External collaborators include the University of Northern British Columbia, Federal University of Pará in Brazil, Federal University of Rio de Janeiro, and other institutions.
