Autumn is a golden season for smallmouth bass fans. Summer’s crowds have vanished. Lakes and streams shimmer beneath canopies of vermillion and amber leaves. Summer-fattened “bronzebacks” are in prime condition and eager to bite.
This season offers some of the year’s best smallmouth fishing, but it’s also a time of transition. The weather changes. Air and water temperatures cool. Smallmouth bass are on the move – shallow one week, deep the next. Where fish nailed most anything yesterday, they refuse everything today. As autumn approaches, many smallmouth anglers cringe with frustration, because their favorite fish are hard to figure out.
You’ll often hear this referred to as the fall turnover season because, on many lakes, the water is “turning over” as the cooling surface layer sinks and warmer bottom water is pushed upward. Fishing can be difficult if you don’t understand what’s going on beneath the water. But turnover needn’t be the nemesis many perceive it to be. Bass fans can actually benefit from this fall phenomenon if they understand it.
During summer, many lakes stratify into three distinct layers. These lakes have a layer of cold water with little dissolved oxygen on the bottom and a layer of warm, moderately oxygenated water on top. Because cold water is heavier than warm water (to a certain degree), the warmer water stays on top and colder water sinks and builds up on the bottom. In between lies a layer of cool, oxygen-rich water called the thermocline. Summer smallmouths usually are found in or near the thermocline because that layer best satisfies oxygen and water temperature requirements.
In late summer or early fall, cooling weather conditions begin lowering the surface water temperature. When the upper layer cools enough, it becomes heavier and starts to sink. This action forces the warmer, lighter water below back to the surface. This water subsequently is cooled and descends as it cools. This mixing or “turnover” continues several weeks until the thermocline disappears, and all water is roughly the same temperature. This mixing effect also reoxygenates deep water.
The end result is that fish formerly restricted to narrow bands of acceptable oxygen and temperature levels are no longer limited in their movements. Bass once barred from dropping into the coolest depths because of low oxygen levels now may roam freely to much deeper water. Likewise, where once fish could not spend extended periods in extreme shallows due to high water temperatures and low oxygen levels, after turnover these areas are acceptable. Bass may now be found deep, shallow or anywhere in between.
Technically, turnover continues until late fall or early winter when the surface water temperature has dropped below 39 degrees F. Water is heaviest at this temperature and drops to the bottom. Cooler water “floats” on top. This is why our lakes freeze from the top down, rather than from the bottom up.
The autumn turnover period can be divided into three sub-periods or “mini-seasons,” each characterized by distinct smallmouth behavior patterns. Understanding how smallmouths behave during these periods can greatly improve your autumn fishing success.
The early autumn mini-season starts right on the heels of summer. The angle of incident sunlight decreases, day length decreases, and water begins cooling. When lakes begin losing heat faster than it is absorbed, smallmouths begin staging along routes into shallow water.
During this time, you should fish the first structure bass find when migrating from deep haunts: creek and river channel edges, flats bordered by deep water, humps and long sloping points. Other good fishing areas include points and turns on gravel bars, rock piles rising into lighted water and trees toppled into deep water.
When you’ve located such structure, you still must entice the fish to bite. Top-notch artificials include 6-inch plastic worms and salamanders, spinnerbaits, jigs, deep-diving crankbaits and spoons. For big smallmouths though, artificials often take a backseat to naturals. Properly presented live baits like crayfish, night crawlers, minnows and sculpins may seduce jumbo bronzebacks when imitations fail.
As autumn progresses, cooler, oxygenated waters reach more deeply in stratified lakes, and autumn turnover begins. When this second mini-season starts and ends depends on local climate and the lake’s depth and structure. But it usually starts when water temperature drops to about 50 degrees.
Autumn turnover brings acceptable levels of oxygen to all water levels, and no discernable temperature change from the shallowest shallows to the deepest depths. Thus, smallmouths scatter and can be found deep, shallow or in between. Finding fish concentrations can be difficult.
Fortunately for smallmouth anglers, many bodies of water don’t stratify in summer, so they don’t experience autumn turnover. Streams are a case in point, and fishing for smallmouths on rivers and creeks is exceptionally good during the autumn turnover mini-season. All waters do not overturn at the same time, so anglers also can switch to waters that have already turned over or those where turnover hasn’t started yet.
In summer-stratified waters, fish shallow water as much as possible during the turnover mini-season. Some bass can always be found in the shallows, especially around rocky structure. Other good fishing spots include tributary mouths, bluffs, steep rock piles and riprap walls around bridges, causeways and boat docks.
A large variety of artificials can be used to entice turnover smallmouths. One hard-to-beat pick is the jig/pork frog combination. Bounce the lure across the bottom near likely smallmouth hideouts using a presentation that mimics a fleeing crawdad.
Crawdad crankbaits are also dynamite lures. These are usually fished in the shallows or worked down rocky inclines into deep pools. They are irresistible to most smallies within eyeballing distance.
The Late Autumn Mini-Season
The late autumn mini-season is characterized by a gradual return to deep-water holding areas. Water conditions, especially temperatures, are generally more stable at greater depths, so bass move deep and often remain in the same area for days, even weeks, at a time. Fishing patterns for this mini-season will generally hold true from late December or early January until early spring in most parts of the South – earlier in the North.
A good reference depth to begin looking for late-autumn smallmouths in lakes is 15 to 25 feet. This varies from lake to lake, depending on the cover and structure present, and it can change as the weather changes. Still, this is a good starting point in most impoundments.
Many late-season smallies are caught over submerged islands and along the outside bends of bottom channels. Bluffs and ledges with stair-stepping drops are also good. A good bottom contour map used with fish-finding electronics can be an invaluable fishing aid during this and other autumn periods.
Jigs and jigging spoons are frequently used under these conditions. Work with light line, jigging or hopping the lure along the bottom or through suspended fish. Vary your jigging action from short jumps to faster, higher jumps until you find how the bass prefer it.
Lipless crankbaits like the Cordell Spot and Rat-L-Trap are excellent lures often overlooked by late autumn anglers. These also can be jigged, and because of their rattling noise, they seem to work especially well in discolored water.
Autumn smallmouths play by their own set of rules, and they like to change them frequently. Still, they can be caught if the angler studies their adversary’s habits.
Autumn anglers who understand the distinct behavior patterns exhibited by the smallmouth bass during the early autumn, autumn turnover and late autumn mini-seasons can discover some of the best fishing of a lifetime.