Winterkill and Surface Aeration
June 15, 2016
In order to sustain fish and other forms of aquatic life, a minimum level of dissolved oxygen (measured in parts per million, ppm) is required. When oxygen levels fall below one milligram per litre for extended periods of time, it can have a lethal effect on fish populations, known as Winterkill.
During the long Alberta winters, layers of snow and ice prevent light from penetrating the surface which prevents aquatic plants and algae from producing oxygen via photosynthesis. When oxygen depletion becomes severe, fish will become stressed and die.
To combat Winterkill the Alberta Conservation Association (ACA) has successfully for a number of years used surface aeration to counteract the effect of oxygen depletion. This process increases the supply of dissolved oxygen in lakes by injecting air through holes in the ice surface.
In July 2015, ACA became aware of potential liability issues under Section 263 of the Criminal Code – Duty to safeguard opening in ice. It has been determined that the continued use of the surface aeration systems could potentially expose ACA staff, management and directors to criminal liability in the event that someone was injured or died as a result of an opening made in the ice. Therefore, during the 2015-2016 winter season, surface aeration was halted and an alternative technique was used. However, this spring’s fish kills were reported at several lakes across Alberta, including lakes Fiesta, Millers and Ironside, in our riding. This only proves this alternative technique inadequate.
There are two potential solutions that can be explored to ensure the health of the Alberta fish population. First, an advisory opinion from the Department of Justice can be requested on how the department interprets Section 263 (1) and how they would prosecute organizations like the ACA if an accident were to occur. Second, enact regulations at the provincial level creating a “strict liability’ public welfare offence that outlines the minimum legal duty that would satisfy the reasonableness standard.
I encourage the ACA and the Province of Alberta to work toward a long term solution in order to resolve Winterkill.