Jeremy,

I’d have to concur with your experience. On many lakes, dissolved oxygen levels beneath the thermocline remain at or above 6ppm throughoutthe summer. I also fish the Whitefish Chain a lot, and clearly, this is one system that harbors sufficient oxygen well into the hypolimnion. Only thing I’d add is that by midsummer, into late summer/early fall, the thermocline usually hovers in the 28 to 36 foot range, descending in depth as surface waters cool into September/October.

On Big Trout of the chain, for example, you’ll mark (and often catch) lake trout, pike and walleyes in 30 to 70 feet of water all summer, even though the thermocline lies between 20 and 40 feet (depending on seasonal surface temperatures). Lots of other examples out there, too.

Interesting patterns Steve. Wondering, though, if you think these shallow water movements truly remain tied to a fall frog migration. Leopard frog numbers have been in constant decline in this area, going back nearly 20 years.

We haven’t seen a significant marsh-to-lake frog migration for many years. As a result, many of these patterns have eroded, or at least, given way to other, slightly different fish movements. Just wondering what your thoughts might be. Thanks!