Regional and Long‐Term Analyses of Stable Isotopes of Fish and Invertebrates Show Evidence of the Closure of a Pulp Mill and the Influence of Additional Stressors

A bleached kraft pulp mill discharging effluent to the Mattagami River in northern Ontario, Canada, closed after almost 90 yr of operation. During its operation, effluent from the mill influenced biota in the downstream areas. To assess shifts in the reliance of biota from mill-derived nutrients, the isotopic composition (δ¹³ C and δ¹⁵ N) of white sucker (Catostomus commersoni) muscle and whole mayflies (Hexagenia sp.) were compared before …