Quebec’s wildlife ministry conducted about a dozen necropsies on fish found floating July 8 near the confluence of the Lièvre and Ottawa rivers, at Masson-Angers, and further downstream. The Ottawa Riverkeeper reported ministry tests found no sign of infectious disease, suggesting a toxin introduced into the river caused the sizeable die-off. Tests have yet to discover what toxin it might have been or when and where the spill occurred. The Riverkeeper reported possibly thousands of fish were killed.