Three Cooke Aquaculture sites in Nova Scotia have reported fish mortalities from extreme cold water temperatures.
A preliminary investigation has found that a superchill happened at the Port Wade aquaculture sites in the Annapolis Basin, Shelburne Harbour and Jordan Bay.
"A department fish health veterinarian has visited the sites in Port Wade and Shelburne and will visit the Jordan Bay site in the next few days to investigate the expected cause of death," said Fisheries and Aquaculture Minister Keith Colwell. "Our provincial fish health veterinarians investigate mortality events to rule out diseases of concern."
Nova Scotia's marine waters stay above freezing most winters. Sustained cold air temperatures can drop the water below 0 Celsius, to the temperature that fish blood freezes, around -0.7 C.
Tides in late February and early March also tend to be high, and contribute to lowering temperatures in sea cages by flooding more shallow areas than usual. Low air temperatures cool the water and receding tides flush the cages with superchilled water. The events happen every five to seven years.
The Department of Fisheries and Aquaculture says that the deaths do not pose any risk to the environment. The company has been speaking with community liaison committees and has been properly disposing of the dead fish.
