Turnover Period

Water Temperature: 60°F to low

50°F range

General Fish Mood: Negative

Many lakes stratify by temperature in summer, with heavier, denser, cold water deep and lighter, warmer, less-dense water on top. Turnover occurs when the temperature on top drops to a point where it equalizes with water temperature below the thermocline. It’s a dramatic event for aquatic life and a visual event for us. When the temperature drops below 60°F, look for detritus, clumps of bottom algae, and old, dead weedstalks littering the surface on lakes that thermocline in summer. The flotsam is dragged topside by currents created as the water in the lake mixes top to bottom. Sometimes the stagnant bottom water of the lake releases a sulfurous odor as it reaches the surface and mixes with the air on windy days. You also may detect suspended debris on sonar.

Turnover is like one big off-switch. The crappie bite, consistent for so many weeks, now abruptly shuts down for several days to a week. Turnover is usually brought on by cool winds after a cold snap or a cold rain that chills the surface of the lake. Shallower bodies of water never develop thermoclines and don’t turn over in fall. The Turnover Period can be a great time to seek crappies in rivers, backwaters, flowages, and other shallow impoundments. Or, if that isn’t an option, look shallow. In many environments, predators like pike, walleyes, and crappies follow hordes of baitfish right up to the beaches and into shoreline cover during the turnover, where they find more environmental stability in terms of temperature and oxygen content. In-flowing creeks and other current areas become key spots. The bite’s slow, but better shallow than in deeper areas. In fact, deeper spots, which crappies otherwise flock to, can be entirely devoid of fish in many lakes during this period.

As the days get shorter in fall, the first really hard cold snap followed by several days of windy, cold weather generally precipitates turnover and heralds the approach of the Coldwater Period. As the temperature on the surface of the lake drops to about 55°F and the water perceptibly clears, coldwater fishing patterns for crappies begin to emerge.

The Coldwater Period (Fall)

Surface Water Temperature: 55°F down to the coldest temperatures of the year

General Fish Mood: Neutral

This period spans the entire time frame from turnover to freeze-up, or down to the lowest temperatures of the year on waters that never freeze. It represents a gradual slowing down and stabilization of the entire ecosystem. The metabolism of a crappie slows in direct proportion to the gradually dropping temperatures. A cooling environment, however, triggers the instinctive need to feed. Winter, and all the stress it represents, is drawing near. Crappies may be moving more slowly, but they rarely pass up an opportunistic meal during this period. Even cold fronts can trigger activity.

In larger, deeper lakes and reservoirs, the passing of the Turnover Period opens the door to deeper, formerly unusable tracts of water that were below the thermocline in summer. Turnover sends oxygenated water deep, providing crappies the chance to forage for invertebrates that were out of reach for months. Minnows soon seek the same areas in search of environmental stability. And, slowly but surely, deeper spots become the most stable areas of the lake. After ice-up, the warmest water is on bottom, the coldest water on top. Water, unlike other liquids, almost reverses the laws of physics as it continues to cool down to about 38°F. At that point, it begins to expand. The coldest water—ice—becomes the lightest. Water is most dense at 39°F and sinks to bottom, so that’s about as cold as water ever gets in deeper portions of frozen lakes. It’s a strange twist of nature that provides for life in northern lakes. If water were most dense at 32°F, lakes would freeze solid from the bottom up.

Within a few days to a week after turnover, crappies begin showing up in deeper haunts. They may linger on the deep edge of healthy weedbeds for some time. Some suspend in the open water of deeper bays or between points over main-lake basins where they spend the winter. Deep rocky points, sunken islands, humps, and other main-lake structural elements experience increasing use by crappies. Transitions from hard to soft bottom at the base of main-lake shorelines crappies use in summer become important, often in depths of 30 to 45 feet in larger lakes. In shallow, bowl-shaped lakes with little structure, crappies may suspend right in the middle of the lake, over basins in the 20- to 30-foot range where they winter.

In reservoirs, crappies begin schooling in deep (15- to 35-foot) creek channels. They collect where the channel bends, usually along the steepest break. Some suspend between primary and secondary points, depending on the type of reservoir. On large rivers, crappies leave current areas for deeper 5- to 15-foot backwaters or connected natural lakes. Huge schools form by late fall. In small rivers without deep backwaters, they move into deeper pools as water levels drop.

In all environments, crappies rarely suspend near the surface after the water cools into the high 40°F range. They may suspend, but increasingly closer to bottom. Typically, the Coldwater Period of fall finds them within 5 or 10 feet of bottom. They begin to hold on bottom, a posture they may assume with increasing regularity as the water dips into the low 40°F range and as it becomes even colder. Inactive crappies are pinned to the bottom and difficult to see with sonar. Active fish rise 5 to 10 feet above bottom, becoming easier to mark.

The stable Coldwater Period is prime time for crappie fishing. Schooling behavior concentrates fish in distinct areas that they continue to use for months. Once they’re located in fall, consistent action lasts for weeks. Successful anglers drift slowly and employ a combination of bottom-oriented techniques, presentations that maintain baited rigs a specific distance from bottom, and vertical jigging. If too many people don’t harvest too many fish, the open-water bite lasts for six weeks to two months.