Officials are trying to turn down the heat on local fisheries.
For nearly two weeks in August, fishing in rivers and streams in a large part of the southwestern corner of the province — stretching north of Calgary all the way to Waterton Lakes National Park — was prohibited between 2 p.m. and 12 a.m.
The regulations came into effect when water temperatures exceeded 20 degrees for three straight days, coupled with low water flows, which experts say can be difficult for fish to handle.
“Trout, char, whitefish and salmon — they have a better need or lower threshold for oxygen than a lot of other fish and that’s partly due to the temperature,” said Henry Komadowski, an environmental sciences instructor at Lethbridge College. “The warmer it gets, the less water can hold in terms of oxygen.”
According to Paul Christensen, a senior fisheries biologist with the province, the timeframe the restrictions were in place for is too short to track changes in the fish population.
But he does believe they had their intended effect.
“Mortalities from angling, even gentle release mortality may be higher than it would be normally so that really is the measure of success — making sure we’re taking some of the pressure off fish during this otherwise stressful period,” Christensen said.
It appears many anglers followed the time-of-day regulations, which ended Sept.1, according to a statement from the Ministry of Justice and Solicitor General.
“As part of the enforcement side of the project, Fish and Wildlife Enforcement Services (FWES) noted that compliance by the public was good, and Albertans were aware of the restrictions in place. Officers only responded to a minimum number of Report-a-Poacher calls and educated a few anglers, who were willing to receive the information and collaborate with FWES,” the statement reads.
“One of the most common questions we get is ‘The river I want to fish in (Eastern Slopes 1) measures water temperatures and they don’t seem to be a problem — why is that restricted here?'” Christensen said.
“A lot of that has to do with the Bow River. It’s a very busy fishery and if we restricted angling on just the Bow and not other places, our concern would be all the anglers that were fishing the Bow would go to a lot of these other, smaller streams and (the fish) may not be resilient enough to withstand a sudden surge of high-angling effort.”
Local outdoor groups think time-of-day restrictions could’ve been imposed earlier this summer.
“It probably could’ve happened a little sooner, to be honest,” said Wade Aebli, the vice-president and land use chair for the Hillcrest Fish and Game Protective Association.
He wouldn’t be surprised if the measures are a keeper and implemented in future years.
“That’s the number one thing is conservation, so that future generations have the same opportunity we do.”