Up here on the St. Lawrence River, the SURFACE temperature was warmer last summer than previous years. While the surface temperature went into the middle 70's, the water temperature at the 30 and 40 foot levels hadn't changed more than 1 or 2 degrees warmer. There is such a hugh amount of water in this River and it is so deep in places (240 feet a short distance from my place) that global warming or whatever doesn't seem to have any effect on the temperatures at lower levels.
I would think the same to be true of Lake Michigan and other deep waters
Zebra Mussels have had a dramatic effect on the river. 20 years ago, visibility was about 10 feet in the water and now it is common to see bottom structure in 30 and 40 feet of water.
We are catching most of our smallmouth bass in 30 to 40 feet of water where I think they are relatively safe from those cormorants.
So far, no effect on the fishing from a global warming standpoint, except that it is getting better.
John
