So long as active perch are grouped and holding in shallow water, it’s preferable to fish for them, because it’s more efficient to fish shallow than to fish deep. First-ice often produces good fishing for perch in shallow water, but for most of the winter, most perch hold deeper than the first drop-off. It’s not just a matter of fishing where most of the perch hold most of the winter. Perch in deep water usually receive less fishing pressure than those in shallow water. Especially after the first few weeks of ice cover, deeper-lying fish often are easier to encourage to bite.

When water mixes during fall turnover, lakes and reservoirs destratify, returning oxygen to the depths. Later, during winter, another phenomenon makes the deep zone appealing. Water is most dense (sinks) at about 39°F. Water chilled below that temperature rises.

Certainly by midwinter, colder temperature bands get bigger from the surface down, pushing the heavier 39°F water off flats into deeper areas. The heavier water rolls down into the basin, carrying along dead weeds, other debris, and food. Minnows, perch, and other fish roll right along with this punch.

There’s lots of food besides minnows in basin waters. Segmented worms called oligochates, averaging close to an inch long, are sometimes concentrated as thickly as 8,000 per square inch on deep flats. Other invertebrates like the aquatic stages of various chronomidae (midges and gnats) are found deep too.

Deep Patterns

Basin depth varies by lake type. In fertile (eutrophic) lakes, basins may run 20 to 30 feet deep. In slightly less fertile (late mesotrophic) lakes, basins may be 30 to 45 feet deep, while in mesotrophic lakes, deep flats might lie 50 to 80 feet down. The fish just roam, particularly in shallower basins, until they find spots where nymphs and larvae are abundant. They may also move, constantly herding packs of minnows, then begin foraging on worms and larvae when minnow schools are reduced.

In this search for deep perch, remember that basin areas aren’t necessarily the deepest water in the lake, but they are the beginning of the deepest water in a particular section of the lake. Perch eventually slide down the drop-off, hit the base of the drop-off, and roam in the general area at the base of the drop-off, particularly in the area where the transition from harder to softer bottom begins. This transition usually occurs within 50 yards or so of the base of the drop-off, so it pays to begin targeting the 100-yard zone beginning at the base of the drop-off into the basin.

Basins often begin at different depths in different portions of the same lake. Say a major shallow bay (big enough to be a small lake) is connected to the main lake. Say the shallow flats around the bay run 10 to 12 feet deep, then drop off into 25 feet, at which point softer bottom begins in the 25- to 28-foot range. Say the deepest water in the bay runs 34 feet. The basin in this bay begins at 25 feet.

In the main lake, by comparison, flats run 12 to 15 feet deep, then in one main-lake section they drop off into 25 to 30 feet, at which point mid-depth flats offering softer bottom begin—followed by another drop-off into 45 feet of water, at which point soft bottom begins in the 45- to 50-foot range. Say depth in this main-lake section eventually slides to 90 feet. Some perch roam those mid-depth flats, but most of the fish are at the beginning of the basin in 45 feet of water. In still other main-lake areas, the basin may begin in 35 feet of water. And so on.

The key to finding the beginning of the basin areas is recognizing where harder gives way to softer bottom. The softer bottom, by the way, usually is clay or marl covered with silt. Super-soft muck doesn’t attract perch for long. The beginning of the basin is a foraging area where I’ve found perch in lake after lake (and reservoirs) that I’ve fished from Montana to Manitoba to Iowa to New York.

But where along the basin edge? That’s not always so easy. Points, for example, don’t particularly impress perch, which don’t seek them as walleyes might. Perch just roam, often in spread-out groups that may cover several hundred yards and include hundreds or even thousands of fish.

These fish, though, aren’t nearly so picky as shallow fish, so it’s really not so difficult to find them if you search systematically. So get a couple buddies, find the basin edge, spread out perpendicular to it—that’s about three abreast—and start popping holes. Drop a bait down, search with electronics, both sonar and an underwater camera, as well as fishing. If you’re fishing, give a spot three minutes or so and move on down the edge.

So much the better if other friends are searching basin areas in other sections of the lake, and you can keep in touch. Once you find an aggregate of fish, usually the word gets out and the troops gather. You’ll have good fishing until you put a dent in the group of fish.

These groups of fish drift along from day to day. It’s not unusual for groups to move 200 yards farther down along a basin edge by the next day. They don’t move much at night, so where you leave them in the evening expect to find them the next morning.

Perch don’t prefer to hold on points, I mentioned a moment ago. Still, as they move through the basin, they move around them as they drift around the basin edge. So points remain a fair place to begin your search. They also gather in the inside pocket where a base of a point turns at shore.

But perch also drift well away from the basin edge, roaming in scattered groups within basin areas. These fish can become difficult to find, particularly when they drop deeper than 60 feet. This often happens, though, and it’s usually the reason perch fishing goes sour during late season. No one can find fish. The muskies ate them all and the world’s coming to an end.

Relax. The fish are still out there. Eventually, they’ll drift back along an edge and everyone will be happy again. In the meantime, look for hard-bottom slashes in basin zones, places where a marl or clay and gravel (or sand) lip rests in deep water. In natural lakes, these are patch areas caused by glacial deposits. In reservoirs, they’re worn humps or mounds that once where farmed hillsides or riverbank mounds. Usually, these areas are slight shallower than the surrounding soft area. In one lake I fish, a portion of basin zone runs about 70 feet deep for a mile in every direction, except for three gradual rises to about 64 feet. The largest of the rises is about a football field long and 30 yards wide. The perch often drift here, always scattered. I usually can scratch a dozen there, enough for dinner, although it may take several hours.

My rule is that you clean what you catch from deep water, or you don’t fish there. Bring perch up and they’re dead—slightly exploded from inside-out by pressure change. Even if they’re four inches long they go home, not onto the ice or back to flounder in the ice hole. Although tiny, they’re an incredibly succulent set of fillets. Saute a couple dozen in butter laced with a little fresh garlic. Just takes a second. Takes a thin Rapala 5-inch fillet knife to do small perch right.