Interesting fall phenomena on my two local hydrilla reservoirs. Every fall I keep my eyes open for bass to start stacking up out in 25 - 30 feet of water. I had speculated that what pushed them deep is the grass dying off and burning up the dissolved oxygen, forcing the bait and the bass out of the grass. This year I am not so sure that is a valid theory. The grass started dying back early October (just like normal, due to reduced daylight hours) but this year the water stayed unusually warm. I looked all October but never marked any fish out that deep.
This past weekend I am cutting across the mouth of a big cove and my fish finder lights up in 27 FOW. The water temperature just this week finally dipped down to 58 - 60 degrees. I normally see that water temperature sometime in October. I dropped a lipless crank down to the marks and caught six 2-3 pound largemouth and a couple of large crappie over the next 90 minutes before they stopped biting. There are still some small 12" largemouth in the shallower grass mats. These lakes have no shad so I never see that migration to the creeks. Forage fish in these reservoirs are sunfish, yellow perch, crappie and crayfish.
Now I am wondering if this pattern is more driven by water temperature and the thermocline pushing deeper and deeper as we head towards the fall turnover. Perhaps that newly exposed bottom presents a feeding opportunity for forage baitfish? Anyone else experience a similar fall pattern on their water?