HUMBOLDT LAKE — Fishers won’t have much luck at Humboldt Lake this year, as the Ministry of Environment chose not to stock it after tests showed oxygen levels are unfavourable for fish survival.
“The Water Security Agency completed three winter oxygen tests at Humboldt Lake this past winter, with the last test done in late March 2021,” said the Ministry of Environment in a statement.
“Water oxygen levels were found to be too low to support a fishery, with the heavy snow pack in early November 2020 likely a contributing factor in creating winterkill conditions.”
A winterkill is when fish suffocate from lack of dissolved oxygen. This can occur in winter because less oxygen is coming into the lake due to reduced flows from inlet streams and the ice and snow covering the water’s surface.
This past winter, there have been winterkill reports on several other lakes with marginal overwintering capacity in the province.
For Humboldt Lake, the Ministry stated that the available oxygen is more rapidly used up since it is a smaller, more shallow lake, resulting in the low levels as were seen this winter.
In June of 2020, biologists with the Ministry of Environment performed a gillnet test net survey in the Humboldt Lake. While there were unconfirmed reports at the time of fish still being caught, the gillnets caught none.
Following the 2020 winterkill, the Ministry planned to introduce walleye fry in June, 2021, pending satisfactory oxygen tests, which ultimately failed.
“The Ministry of Environment will continue to monitor conditions at Humboldt Lake but will not consider restocking this waterbody until the conditions return to a more favourable state for fish survival,” they stated. “To resume introducing fish species into the lake, at least one year free of winterkill conditions, with suitable oxygen levels, is required. Therefore, no stocking of this lake is planned for 2021.”