Comment on “Fish Remain High in Selenium Long after Mountaintop Coal Mines Close” (Environ. Sci. Technol., 2026, DOI: 10.1021/acs.est.5c10900)

“This Comment evaluates the interpretation and conclusions presented in “Fish Remain High in
Selenium Long after Mountaintop Coal Mines Close” by Cooke et al. (2026). While the study
provides valuable data on selenium concentrations in fish tissue from Crowsnest Lake, several
limitations may affect the strength of the conclusions. These include a lack of sufficient temporal
and site-specific context to interpret bioaccumulation, limited evidence to support attribution to
legacy mining, and the extrapolation of ecological and population-level effects in the absence of
supporting biological data. Additional uncertainties arise from cross-system comparisons and
mechanistic linkages that remain speculative. Overall, the conclusions regarding persistence,
source attribution, and ecological risk may not be fully supported and would benefit from a more
comprehensive, hypothesis-driven framework.”

Guy Gilron, MSc, RPBio/Senior Environmental Scientist/Principal
Borealis Environmental Consulting Inc

Read the Article: ES&T rebuttal to Cooke et al 2026_FINAL