Big Muskego Fish Feel Effects of Heat Wave

In one respect, the term 'gin clear' is good when you're talking about lake water quality. Photos from a tour on Big Muskego Lake seem like there's no water there at all as the bottom of the lake is easily visible.

However, in a second summer where temperatures have reached the 100s, it's not so great for the fish, which are dying off in the thousands on Muskego's big lake.

"We're seeing thousands of northern pike, it's just been too hot on the big lake. Bass Bay is better, as the fish are finding cooler water there," explained Muskego's Conservation Coordinator, Tom Zagar.

Much of the 2,000 acres of Big Muskego is considered more like a deep-water marsh (referred to as the big lake), with depths reaching only six feet. Bass Bay provides deeper cover, and doesn't have the same clarity as the rest of the lake. It's not as desirable for water quality, but it does give the fish a break from the heat of the day.

"Northern pike start to die when water temperatures reach 88 to 90 degrees," Randy Schumacher, DNR district fisheries manager told Journal Sentinel sports blogger Paul Smith. "They are very tolerant of cold water and even low oxygen, but not heat."

Zagar said the kill, which was accelerated in last week's 100 degree temperatures over several days, has affected all ages of the species, not just the larger fish.

The good news: other inland lakes have been seeing blue-green algae, but so far Little Muskego Lake and it's Big brother haven't had that problem. To that, Zagar also said that its proliferation often comes from efforts to kill off other vegetation, which they have approached with caution especially on Big Muskego.