Scores of northern pike are dead by Riel Pond after warm weather and open water drew them to their doom.
River watchers spotted a large number of dead white fish in a patch of open water on the Sturgeon River Thursday. The patch, located by a stormwater outlet for Riel Pond, was full of floating bodies and surrounded by partially eaten fish.
Local observer Elke Blodgett says she found the fish by following a coyote as it ran across Big Lake. The coyote soon arrived at the patch and started squabbling with magpies over the free food.
There were probably about 100 dead fish in the area, Blodgett says. “They were splattered all over the ice,” she says, some of which were about a foot long. “Yesterday [Wednesday] there were only a few fish heads, but today there are hundreds packed in the ice.”
An official with Spencer Environmental also spotted the kill and reported it to the city, says environmental manager Leah Jackson. (Consultants regularly inspect the area looking for leaks from old landfills.) Alberta Fish and Wildlife investigators are aware of the deaths and have identified the fish as northern pike.
Low oxygen levels in the water likely killed the fish, Jackson says, a phenomenon called winterkill.
“This does happen often when the weather warms up like this.”
Water from the outlet had melted the river’s ice and agitated the water’s surface, oxygenating it. The fish, sensing the oxygen, had likely swarmed the opening, used up the oxygen, and died. “It does smell quite a bit,” she adds.
The fish-kill was unrelated to the open patch of water near the community garden, Jackson says. That patch, located about half a block to the east, is caused by groundwater produced by recent excavation.
Ice and shallow water make winterkill a regular occurrence on the Sturgeon, according to fisheries experts. In November 2002, Fish and Wildlife officials moved several thousand fish from the Sturgeon to the North Saskatchewan to help them survive.
Residents should leave the fish for the animals, Jackson says, as they have started to rot and aren’t fit for consumption. “The coyotes and magpies will make short work of it.”
Anyone who spots fish in distress on the Sturgeon should call the Report A Poacher Hotline at 1-800-642-3800 so they can send crews to rescue the fish.
