The recent Pine Lake walleye kill is a classic example of things gone horribly wrong.
On Thursday, Alberta Health Services warned that the waters are poisoned by toxic blue-green algae blooms, and advised people and their pets to stay on shore.
The oxygen-robbing blooms may be linked to the death of what one angler described as hundreds of large, bloated walleye, bobbing on the surface or washed ashore.
Let this be a wakeup call to the Counties of Red Deer and Lacombe when approving recreational subdivisions the size of small towns close to the shorelines of Gull and Sylvan Lakes.
Lakes, no matter their size, cannot withstand massive intrusions that disrupt the natural water cycle. Wetlands, large tracts of mature forests, and forests floors at the lakes’ edges must be preserved to act as natural filters that purify the waters.
We don’t need a steady flow of nutrients from agricultural practices, and sewage and yard fertilizers from cabin dwellers, to speed up the deterioration of water quality.
Pine Lake is suffering as the result of practices dating back for years.
“I’ve been coming to this lake my whole life, and something is terribly wrong,” said Tracy Gorr, who discovered the dead fish along with a friend on Wednesday. She said she was horrified. “There were hundreds of dead walleye all over the lake. They were just floating, these huge nice fish.”
Gorr and fishing pal Wayne Ferris took a cruise in their boat around the lake. They saw swirls of turquoise “sludge” on the water; dead fish everywhere.
“I’ve never seen anything like this. . . . This is not right,” said Ferris, who has fished the lake since 1974.
Pine Lake is “eutrophic,” meaning its nutrient-laden waters — usually linked to fertilizers or sewage — are feeding a dangerous cycle of algae growth. During summer, the algae consumes the nutrients and blooms on the surface. When it dies, it settles to the bottom and rots, robbing the water of oxygen in the decaying process creating a dead zone — water void of oxygen.
That could explain the recent walleye kill. The species prefers cooler, deep waters during summer. In a small southwest pocket of Pine Lake’s almost 1,000 acres of surface area, the water reaches a maximum depth of around 14 metres (45 feet) — ideal for walleye. But also ideal for suffocating, dead water.
The worst-case scenario for eutrophic lakes is blue-green algae blooms, experienced at Pine Lake. It signals advanced stages of deteriorating water quality.
Alberta Health Services said blue-green algae “produces a toxin that can cause serious illness to animals or humans who drink the water or have skin contact,” including liver damage.
In earlier years, Pine Lake, surrounded by farms feeding the waters with livestock run-off, was ripe for the eutrophication cycle. Then came tourism, crowding its banks and adding to the pressure.
In the 1970s, the Advocate reported on studies stating that Pine Lake waters were hurting and immediate action was required.
That was more than 30 years ago.
The lake’s water quality has become a concern, and conservation and educational efforts were launched, but last week’s discover of algae suggests that not nearly enough has been done.
Does this recent walleye kill mean it’s too late?
Lake Winnipeg, long a victim of reckless environmental practices, has been dubbed “Canada’s sickest lake” — a victim also of toxic algae blooms.
What was once a small patch of blooms first noted in 1990 now blankets more than half of the massive 24,500-square-km lake most summers. In 2006, the blanket covered almost the entire lake.
Some experts say the world’s 10th largest lake won’t recover, ever.
If algae blooms can conquer such a huge lake, Central Alberta’s smaller lakes most certainly are easy pickings.
This crisis demands immediate attention, and a re-examination of all development plans around Pine Lake and other lakes in Central Alberta.
Rick Zemanek is an Advocate editor.