The dark side of docks, bridges and piers hold special appeal for fish and the anglers who pursue them. As I’ve explained in the past, the heat that warms things up in a fish’s habitat is provided by the sun, and the longer the weak rays of spring we are now experiencing have to broadcast their meager heat across the water and surrounding landscape, the higher the water temperatures can become. A shallow, dark-mud or gravel flat or wood-filled bay that may be void of fish on a cloudy April morning may warm up considerably after the clouds break and the waters receive a few hours of sunlight—enough so that baitfish and aquatic insects find its temperature high enough to shake them from their cold weather doldrums and get them on the move.
Crappies, bass, walleyes, trout and other opportunistic gamefish known to be active in the early spring will be hanging around these early spring warm up sites and will be on the prowl by afternoon to take advantage of any baitfish or other critters that may make themselves available for a meal. Of course, these locales make great places to anchor your boat nearby and cast fake entrees or examples of the real thing—complete with a hidden hook to seal the deal—into these pre-season honey-holes.
Bottom materials consisting of black mud, dark gravel or wooden cover absorb more sunlight than do similar substrates of lighter shades, which reflect those warming rays. Although cement bridge pilings and limestone rip-rap will eventually warm up from the sun, the darker-colored wood cover is more appealing to early season fish; the darker color of tree stumps and deadfall and wood boat dock pilings absorbs more of the heating rays of the sun than does the lighter-colored stone and radiates that warmth into the adjacent waters. The heat is relative and the warming range can be very localized; the baitfish and insect life that are affected by the minute changes in temperature may have to be within inches of the structure to benefit from the secondary heat source. The gamefish that come to feed on the thawing food supply, not so much. Predator species can prowl the perimeter and dart in to snap up unsuspecting minnows or insects or larvae before retreating to cooler water or nearby cover to hide as they await their next meal opportunity.
Because the water areas that are warming first and fueling the activity progression of insects and baitfish and gamefish are shallow, the predators that feed there can be skittish and selective. Small baits and subtle presentations are often called for, and you may have to delicately place your baits right in the face of the fish you want to catch. Bobbers come into play to suspend and keep baits such as small live minnows right in the strike zone until gamefish such as trout, walleyes, catfish or crappies locate the meal and dash in to dine.
When deciding where to wet a line on a cool spring day, note more than the presence of wooden cover. Take a look around and see if you can boat into places on the northern extreme of the particular waterway offering southern exposure, where the longest, strongest presence of the sun’s rays can be felt and its effects realized. The shallow flats on a lake’s northern end can heat up days and even weeks earlier than the main water body—and we’re talking water temperatures and the fast, early-season angling action for the fish that seek the heat.