Judging from the minuscule number of trophy pike I see caught during the summer months, most folks are unaware of the cold-water connection. In case you’re not up on the subject, let me give you a little history: While fishing the Mississippi River back in the early 1970s, I discovered that certain spots routinely produced big pike during the hottest part of the summer. What drew the pike to these locations was a mystery until I went back to fish them in winter: Each spot was impossible to icefish, because the ice gave way to open water directly over the area where the fishing had been so good six months earlier.
That was the answer: Every one of my summer hot spots was fed by a spring. Back then, I was conducting fisheries studies on the Mississippi River for the Minnesota Department of Natural Resources, so I began examining the cold-water connection in earnest. Most of my work was conducted on Lake Pepin, a 25,000-acre widening of the Mississippi along the Minnesota-Wis-consin border. Using electrofishing gear, I found huge pike holding in spots where no one would dream of fishing for them. I remember shocking up four pike between 15 and 20 pounds off a two-foot-deep sandbar at the mouth of a small trout stream. The temperature at the outflow was 60 degrees, while the surrounding water was 78 degrees.
Confirming my theory, I also found big pike in boat harbors where bottom springs had been exposed by dredging, in spots where the cool runoff from ponds fed by artesian wells flowed into the lake and around the mouths of coulee streams-spring-fed trickles emptying into the river. In some cases, temperature readings in these spring holes were as low as 48 degrees, the same temperature as ground water in that part of the country.
Based on those early discoveries, and on subsequent study of the cold-water connection, I’ve refined a pattern that has helped me catch trophy pike during the worst heat of summer, when many anglers contend that the big fish quit biting. The pattern is based on three principles.
**I. Big pike have different temperature requirements than small ones. **
Numerous biological studies have shown that northern pike prefer water temperatures in the 67- to 72-degree range. That range might be about right for pike up to five pounds, but as the fish grow larger, their temperature preference changes. By the time they reach seven pounds, they’re looking for water in the 50- to 55-degree range. It’s not surprising that biologists would fail to uncover this distinction because practically all temperature-preference studies are done with juvenile fish under laboratory conditions.
**II. The higher the ambient water temperature, the stronger the draw of point sources. **
Cold water really does not begin pulling in big pike until surface temperatures get up to the 70-degree mark. Until that happens, you’ll catch them in shallow weed beds right alongside the smaller fish (explaining why the great majority of trophy pike are caught in early spring and late fall).
By the time the surface water has reached 75 degrees, however, practically all big pike have moved out of the shallows and into cold-water holding zones. I look for water that’s at least 10 degrees cooler than the surface temperature. If water that cold is unavailable, the pike might be satisfied with water that’s only two or three degrees cooler.
The best pike fishing I ever experienced came on an August day with the air temperature hovering right around the 100-degree mark. My electric thermometer registered 82 degrees on the surface, but the water temperature 12 feet down was 48 degrees. In less than 45 minutes, I pulled in five pike between 13 and 22 pounds, all from an area about the size of an average kitchen. The fish were drawn like moths to a yard light by the icy water provided by an upwelling spring.
And when a batch of ke is removed from a spring hole or other cold-water pocket, more of them move in, usually within a day or two. These spots are fish magnets, in the truest sense of the term.
**III. Isolated point sources of inflowing cold water are best. **
The most productive cold-water situations occur where a spring or cool-water stream flows into a small bay, harbor or other isolated spot that allows the cold water to collect. If the water instead runs directly into a river flow, the current will quickly dissipate it and negate its effect. Likewise, if cool water flows into the middle of a lake, the wind mixes it with the surrounding water and the temperature differential is minimized.
Because cold water is denser than warm water, it hugs the bottom. Consequently, so do the pike. Sometimes the cold-water layer from a point source is a band only a foot thick. But even in an isolated spot, blustery weather can create enough mixing to disperse the cold water. When that happens, the pike disperse. As a rule, pike fishermen like cool, windy, overcast weather. But to make the cold-water connection, you want the opposite: hot, calm, sunny weather.
You can find point sources of cold water by exploring the bottom with the probe of an electric thermometer. I even know a few anglers who walk through the shallows barefoot, feeling for icy spring seeps. The easiest way to find these cold-water point sources, however, is to scout them after freeze-up. Spring water remains a constant temperature year-round, so you’ll see open water in the ice wherever springs flow in. I know one guy who took this scouting method to the extreme when he chartered a small plane so he could fly over his favorite pike lakes and mark spring holes on a map. Point sources of cold water are most common in big rivers, but they can also occur in lakes, particularly where cold-water streams flow in.
Deep lakes offer another cold-water refuge in summer: in the zone below the thermocline, which is called the hypolimnion. In very fertile lakes, pike are unable to use the hypolimnion because the water does not maintain the minimum amount of oxygen that pike require (3 parts per million). But in lakes of lower fertility, the oxygen level is adequate and pike roam freely in the depths, feeding on ciscoes, whitefish, burbot, smelt or whatever other kind of cold-water forage is present.
From an angler’s standpoint, it’s much better to find pike around a point source than scattered throughout the depths of a lake: You know exactly where to go and, if the pike are there, you’ll find out unmistakably-in a few minutes. Even if you do locate deepwater pike, there’s no guarantee they’ll be there next time you come back. Still, you can record some phenomenal catches in both situations, if you use the right methods.
Point-Source Techniques
In pockets of cold water, nothing works better than a big minnow dangling from a slip-float. In cold temperatures pike become disinclined to chase fast-moving baits. Set your float so that the bait dangles right in the fish’s face.
Before anchoring your boat, hover directly over the pocket you want to fish and take a few temperature readings to determine the borders of the cold-water zone. If you don’t have an electric thermometer, for only a couple of bucks you can buy a Vexilar Deptherm. When you lower this pocket-size device to the desired depth and pull it up rapidly, the Deptherm traps a small volume of water and reads its temperature.
Once you scope out the cold-water zone, anchor alongside it and toss out a 9- to 12-inch baitfish. I normally use a sucker, because that’s what is usually available in summer, but any large bait-fish will work. If you can’t buy baitfish that big, head for a small creek with a can of angleworms and catch a batch of chubs or whatever else is biting.
Since this type of fishing doesn’t require much casting, you can use almost any kind of rod and reel, but your line should be at least 17-pound-test. Ideally, I prefer a medium-heavy flippin’ stick and a baitcasting reel spooled with 20-pound monofilament. I’ve seen pike hit the bait so hard that water actually flies up in the air when the float plunges under. Don’t wait long to set the hook: I usually let them take it for 20 to 30 seconds; then I rapidly reel up slack until I feel the fish’s weight, and set the hook. This last sequence is important, because the fish often puts a loop in the line as it swims off and if you don’t reel up all the slack, you won’t get a firm hookset.
Deepwater Techniques
When pike are scattered in deep water, the only practical way to fish for them is to troll with big crankbaits or minnow baits. My favorites include the Super Shad Rap in perch or crayfish colors and the Cisco Kid Super Husky in a shiner finish. Some crankbaits have long lips that can take them down 20 feet or so. But the fish are frequently still deeper, so I usually rig the lure on a three-way-swivel rig, with a 4- to 6-ounce bell sinker.
My trolling outfit consists of a 61/2-foot, heavy-power baitcasting rod (Berkley Series One, model B-50) and a sturdy baitcasting reel (Abu-Garcia Ambassadeur, model T5600C) spooled with 30-pound-test Gorilla Braid. The thin-diameter, no-stretch line makes it easier to get down and feel the vibrations of the bait so as to determine when it’s fouled. Then, a quick snap of the stiff rod usually frees any weeds or debris.
The technique is simple: Position yourself over a main-lake breakline and follow a specific contour. I normally concentrate on mid-lake structure, particularly sunken islands that top out at 20 feet or more, but any deep breakline can hold pike. Begin trolling along the 25-foot contour, letting out just enough line so the sinker occasionally ticks bottom. Work your way out in five-foot intervals, and don’t be surprised if you catch pike at depths of more than 40 feet.
Be sure to check your lake map for any deep rock piles, which can be as much a summertime pike-magnet as shallow spring holes. If you have a sensitive graph, you should be able to see the pike hugging the bottom. Using a medium-heavy spinning outfit and 10-pound mono, try vertically jigging at depths of 30 to 40 feet using a 3/8-ounce fluorescent orange or orange-and-chartreuse jighead attached to a short wire leader and tipped with a four- to five-inch chub, sucker or shiner.
Mastering these cold-water tactics can add a whole new facet to your summertime fishing repertoire. The size of the pike that prowl spring holes and deepwater retreats never fails to amaze me. But what is more surprising is the number of summertime pike anglers who continue to flail away at the same shallow weed beds they fished in spring. So the next time yore much casting, you can use almost any kind of rod and reel, but your line should be at least 17-pound-test. Ideally, I prefer a medium-heavy flippin’ stick and a baitcasting reel spooled with 20-pound monofilament. I’ve seen pike hit the bait so hard that water actually flies up in the air when the float plunges under. Don’t wait long to set the hook: I usually let them take it for 20 to 30 seconds; then I rapidly reel up slack until I feel the fish’s weight, and set the hook. This last sequence is important, because the fish often puts a loop in the line as it swims off and if you don’t reel up all the slack, you won’t get a firm hookset.
Deepwater Techniques
When pike are scattered in deep water, the only practical way to fish for them is to troll with big crankbaits or minnow baits. My favorites include the Super Shad Rap in perch or crayfish colors and the Cisco Kid Super Husky in a shiner finish. Some crankbaits have long lips that can take them down 20 feet or so. But the fish are frequently still deeper, so I usually rig the lure on a three-way-swivel rig, with a 4- to 6-ounce bell sinker.
My trolling outfit consists of a 61/2-foot, heavy-power baitcasting rod (Berkley Series One, model B-50) and a sturdy baitcasting reel (Abu-Garcia Ambassadeur, model T5600C) spooled with 30-pound-test Gorilla Braid. The thin-diameter, no-stretch line makes it easier to get down and feel the vibrations of the bait so as to determine when it’s fouled. Then, a quick snap of the stiff rod usually frees any weeds or debris.
The technique is simple: Position yourself over a main-lake breakline and follow a specific contour. I normally concentrate on mid-lake structure, particularly sunken islands that top out at 20 feet or more, but any deep breakline can hold pike. Begin trolling along the 25-foot contour, letting out just enough line so the sinker occasionally ticks bottom. Work your way out in five-foot intervals, and don’t be surprised if you catch pike at depths of more than 40 feet.
Be sure to check your lake map for any deep rock piles, which can be as much a summertime pike-magnet as shallow spring holes. If you have a sensitive graph, you should be able to see the pike hugging the bottom. Using a medium-heavy spinning outfit and 10-pound mono, try vertically jigging at depths of 30 to 40 feet using a 3/8-ounce fluorescent orange or orange-and-chartreuse jighead attached to a short wire leader and tipped with a four- to five-inch chub, sucker or shiner.
Mastering these cold-water tactics can add a whole new facet to your summertime fishing repertoire. The size of the pike that prowl spring holes and deepwater retreats never fails to amaze me. But what is more surprising is the number of summertime pike anglers who continue to flail away at the same shallow weed beds they fished in spring. So the next time yo