A harmful plankton bloom and poor water conditions caused large mortalities at three Cermaq salmon farms in northern Clayoquot Sound near Tofino, with up to 185,000 fish lost at one site. DFO says disease was ruled out; critics warn the die-off could affect wild salmon and the marine environment.

Authorities have detected blue-green algae in Loch Moy, south of Inverness, and are urging the public and pet owners to avoid contact with the water. Warning signs are being posted as agencies investigate potential health risks.