Most of us Bass anglers have learned that it’s much easier to pattern our bass when they settle into an area for an extended period. Still, there are two seasons of the year when the bass really go on the move: spring and fall.
Figuring out what’s happening with bass in early spring is relatively simple, it’s spawning season and the fish are coming out of their deep-water winter haunts and moving shallow to find appropriate habitat to “get it on” with their respective partners. After the spawn, bass generally drift back out toward deeper water, where they spend the summer, their home territories are mostly determined by the food supply available to them. Bass and other anglers all get into our respective “grooves” and everything’s fine & dandy for a while.
Then cooler weather shows up and everything starts to go crazy for fishermen — sometimes in a hurry, like this year. In many lakes north of that “South of the border” sign, what is generally termed “fall turnover” occurs. This is a weather-induced phenomenon that takes place as cooling surface water displaces the warmer water below and causes fish to move in response. As anglers, we too have to move, altering our fishing approaches to contend with the seasonal weather shift.
When fall turnover occurs in a given lake, the thermocline that separates the warm, nutrient-rich water above from cold, sterile water below dissipates, and dissolved oxygen becomes more prevalent. Because of the change to their environment, fish that had hovered at the mid-depth thermocline during the summer tend to disperse over a wider area, much like they would when spring floods cause a lake or river to temporarily burst outside its banks. Understanding the complexities of the fall turnover is the first lesson anglers must learn about the fall transition.
Keep this in mind; Bass, like all landlocked lake fish, are prisoners of their own environment, they can’t change it or escape it. Fish have to move or adjust to major changes that affect their ability to survive. When bass aren’t concerned with spawning, or getting enough dissolved oxygen to survive, they’re out looking for their next meal. It’s mainly a bass’s need for food that gets its fins flapping as autumn progresses.
Changes in water conditions‚ temperature, nutrient content and the concentration of oxygen will inevitably displace baitfish and their predators will follow them. This transformation often occurs in steps but can sometimes be quite dramatic. Bass patterns that had been consistent for days or even weeks, might just all of a sudden fail to produce at all.
The biggest difference between fishing in summer and fall is that, in the summer, we generally realize that we have to fish above the thermocline in order to find fish. If you fish below the thermocline, the water is older and generally devoid of dissolved oxygen, making it inhospitable to the fish. Most (but not all) lakes will stratify; bigger, deeper lakes tend to stratify to greater depths than smaller, shallower lakes, reservoirs or ponds.
The thermocline boundary prevents water from mixing from top to bottom. But once the water cools in the fall, and those damn autumn winds rough up the surface, the water on top becomes more dense and begins to actually sink, (yes, dense water can actually sink) this causes the entire lake to mix from top to bottom, or as we know it, the dreaded “Fall turn over”.
Now the fish populations will all have the entire water volume of the lake to occupy, of course, finding those fish becomes difficult, as does getting their attention when you do actually find them. Often the newly mixed water has a lower oxygen content and also contains nitrogen and other toxic by-products of decay, it becomes muddy or murky in appearance, which will initially make fish sluggish and put them off their regular feed.
The first move we should make is to fish the shallows. Shallower water warms more easily, holding abundant oxygen‚ and therefore baitfish and bass‚ especially during the heat of an Indian summer day. In addition, wind driven wave action oxygenates the surface water much better than the impenetrable deeper water. To me, what ends up happening in the fall more than anything else is that the fish population as a whole‚ bluegills, minnows, perch‚ whatever, all begin to move up on to the flats. When the lake starts turning over, experienced pan fishermen will always go shallow or they’ll catch nothing.
So when does this all happen? While fall turnover occurs at different times on different lakes the general rule is right around the 50 degree surface temp mark. Turnover is by no means a “death sentence” for angling, on the contrary, now you can use the turnover to guide you to the likely “hang outs” for just about all freshwater fish species, not only bass.
Here’s a quote from an interview with noted bass immortal KVD; “It’s amazing to me how long bass will stay shallow, lakes that have a lot of flats extending out from their shorelines will have fish shallow until they freeze over.”… VanDam recommends staying just out from the offshore edges of flats and burning a spinnerbait across them. He uses his namesake 1/2-ounce Strike King spinnerbait with two No. 4 willowleaf blades. “I like the windy side of the lake with flats from two to five feet falling off into six to 10 feet‚ the first drop-off away from the bank,” says VanDam. “Speed is critical. Burn it back and just when it’s going over the drop, stall it‚ just change the rotation of the blades for a second. The bass will knock the rod out of your hand.”
I totally agree with KVD in this case, he’s actually referring to a reaction strike when he stall’s his spinner in the strike zone, it’s the most violent of bass strikes there is, but you can get the same results from a number of different baits, not only a spinner. I see many bass anglers here in Ct. targeting deep water as soon as the lake temps drop into the upper 50’s, what they may not realize is that they’re missing out on the shallow water bite big time! The heaviest of largemouth will frequent the shallows until hard water appears, once the ice begins, they’ll make their annual pilgrimage to the more secure and comfortable wintering depths. This deep water migration usually won’t occur until well after fall turnover or when temps are 45 degrees or below. So keep fishing those shallow spots right up until you see ice beginning to form, you’re sure to haul in some of your biggest largemouth’s of the year!