Monday June 23, 2025
The Suburban —
The global abundance of salmon, trout and similar fish (salmonids) has declined by nearly 40 per cent since 1980, according to a new study by Concordia researchers. The study, published in the journal Fish and Fisheries, is based on a new dataset built from published materials spanning more than 1,000 rivers and streams across 27 countries and 11 salmonid species.
The researchers compiled data from over 330 sources, including academic studies, government reports and grey literature — unpublished or non-commercial materials such as technical documents, internal agency reports and environmental assessments. Most of the data came from the United States, Canada and New Zealand. Fish sampling spanned 84 years, from 1937 to 2021.
Lead author Kyleisha Foote, who received her PhD from Concordia in 2024, is now a postdoctoral fellow at Memorial University in St. John’s, N.L. She says the sharp decline in salmonid biomass — meaning the total weight of living organisms in a particular area — is not surprising. “The findings were not striking to me because there has been a lot of reporting around salmonid and other freshwater fish decline, but those studies were usually of local populations from around the world,” she says.