Stream Fishing Feeding Habits
Lure Selection for Streams Fishing Turbid Water Bait Selection for Streams
Catch and Release Lake Fishing Lure Selection for Lakes Lake Angling Techniques
Fishing for Smallmouth Bass
By Tom Putnam, Fisheries Biologist, Iowa DNR
Smallmouth bass are an often-discussed, but not so often sought-after fish in Iowa. Nearly every fishing magazine contains a story or two where the writer extolles this fish as a hard-hitting, scrappy-fighting, aerial acrobat of the sunfish family. Those who have experienced smallmouth angling know that this praise is justified.
Little wonder should exist that there has been in recent years renewed interest in fishing for this species. Smallmouth, although plentiful only in places with select habitat, are distributed throughout the state. Many anglers need to travel only a short distance for a chance to fish for this fierce fighter of the black bass family.
Although smallmouth in Iowa are found in both lakes and streams, they are, by far, more widespread and numerous in our flowing waters. Fishing for smallmouth by wading or floating a stream offers a pleasurable opportunity to escape from the crowds and immerse oneself in nature. It is a chance to encounter deer, beaver, hawks, owls, kingfishers, and other wildlife in their inner sanctum along undisturbed stream corridors. At times, one can almost imagine the meaning of "wilderness" -- even in Iowa.
Stream angling for smallmouth is appealling because catch rates are usually higher than in lake fishing. Once an angler becomes able to identify the habitats normally used by the fish in different seasons of the year and during various water conditions, fish can often be located with ease.
In the spring, prior to spawning, the water temperature is usually in the 40 degrees to 50 degrees F range. Water levels are normally high this time of year, allowing the bass to move freely and disperse from winter habitats. During high flows, fish are often found closely associated with large boulders, fallen tree snags, and undercut banks. Structures such as this divert strong currents and create loafing habitat for smallmouth. These areas are also populated by forage species making it convenient for the bass to feed without having to work against the strong current.
In mid- to late April in Iowa, smallmouth begin to migrate toward traditional spawning sites where the males construct nests. On large streams, the fish usually move up small tributary feeder streams in search of rock or gravel substrates with moderate to low stream velocity. Smallmouth may utilize sandy substrates for spawning, but they prefer rock and gravel. In smaller streams, spawning often takes place in the mainstream itself. Immediately prior to spawning, both sexes readily take lures as their pre-spawn urge to forage often reduces caution. As the time for spawning approaches, the males establish nests and territories; they are at this time very susceptible to angling. Many smallmouth anglers catch and release fish during these periods, especially female bass. Smallmouth bass is not a species that is hatchery reared and stocked in this state, and the success of natural spawns dictates the quality of the fishery.
After spawning, females move immediately into deeper water. Males stay on the nests as guardians of the fertilized eggs, but following the hatch they also move to deeper pools. In the case of fish spawning in tributaries, movement is toward the parent stream.
The typical habitat in which smallmouth relocate following spawning is largely dependent upon stream-water levels. High flows enable fish to utilize habitat often too shallow or dry in low flow periods. Smallmouths disperse and use all of the rocky and log-fall habitat containing two or more feet of water. Rocky habitat is usually selected over log jams.
As water levels recede through the summer, fish are forced into pockets of deeper water. These are associated with rock riffles, log snags and cut-banks. At this time the fish congregate into schools and become more vulnerable to angling. Again, rocky habitat is preferred. A deep hole above a riffle is sure to hold fish. Likewise a cut-bank is also selected, especially if it contains an assortment of boulders that are 2 to 3 feet in diameter and located in several feet of water.
Time of year and conditions dramatically affect smallmouth feeding behavior. In one Iowa study of smallmouth fishing the following observations were made on feeding behavior. Following spawning... "there was a period of several weeks when bass readily took lures. Many adult males seemed to retain their nest-defending trait and struck lures retrieved close to them. Smallmouth were least susceptible to angling between mid-June and mid-July following spawning and post-spawning, and the extreme clarity of the water seemed to induce adult smallmouth to concentrate into the larger and deeper pools. Schooling was first observed in mid-July. Smallmouth schooled as a species and with three other species of fish, quillback, river carpsucker, and white sucker. Large bass tended to school with the larger suckers. Smallmouth showed little fear when schooled and often allowed anglers to wade within 20 feet of the schools. They were highly susceptible to angling when schooled."
As fall approaches, smallmouth bass remain close to the prime habitat structures. Most of these areas are similar to summer haunts. Due to lower sunlight intensity and cooler water temperature the fish will often be found in shallow water. The exception will be during the occasional wet fall when water levels are abnormally high. Bass will disperse more during these times.
Once an angler becomes accustomed to identifying the probable location of a stream smallmouth, the proper lure or bait must be selected that will entice the fish to strike. Common sense often rules in lure selection. Factors to consider include food preference, time of day, water color or the amount of turbidity, water depth, and weather conditions.
As with any predator fish species, one of the most important assets to a successful fishing trip is the knowledge of forage preference. For many species, the preference changes, depending on the availability of the prey. Smallmouths are no exception. In spring, minnows and shiners are numerous and are the favorite food choices. As early summer approaches crayfish become abundant, especially in shallow rock riffle habitat. This is the number one food choice for smallmouth. As summer progresses and crawdad numbers decline, due mostly to predation by bass, smallmouth must again rely heavily on the more available minnows. Interspersed throughout this feeding pattern are periods of increased aquatic and terrestrial insect foraging, especially at peak insect hatches. One that is especially important is a hellgrammite, the larval form of the Dobson fly. This insect is abundant in some stream riffle habitat throughout summer and is aggressively sought by bass. They are easily collected for bait by simply turning over rocks.
Lure Selection for Streams
The smart angler will select a lure that closely resembles the preferred food item at that particular time of year. Prior to the spawn and later in post-spawn, when bass again resume active feeding, lures that resemble minnows are most effective. Single blade spinners work well, as do leadheads and, occasionally, shallow running minnow shaped crank-baits. When using spinner-baits, or any other lure for that matter, one should think small. Size preference of a food item for smallmouth is smaller than for its relative, the largemouth bass. Use of No. 0 or 1 size spinners, one-eighth to one-fourth ounce crank-baits, or the same-sized leadheads will provide best results.
During mid-June to mid-August, when crawfish are abundant, lures that mimic this crustacean are the top choice. Water levels are lower during this period and the fish are more concentrated, relying on the deeper holes around riffles and cut-banks. Crawfish colored crank-baits, especially those that resemble both the color and action will usually yield fast action. Crank-baits that hug the bottom, bouncing off rocks, or stir up a small cloud of silt can really trigger a response from a hungry smallmouth. Leadheads in crawfish colors also work well, especially fished in an erratic motion by raising and lowering the rod tip.
In late summer and early fall, after the crawfish population is depleted, minnow imitating lures are again the top producer. Leadheads work very well, particularly the soft-bodied twister tail variety in white, yellow, or chartreuse. These lures allow the angler to work the bottoms of the deepest pools where smallmouth seek protection from sunlight.
A factor that appears to be less important, except when using surface lures, is the time of day. Smallmouths will readily pursue surface presentations, especially in the early morning and late evening hours. The cast must be made past the spot suspected of holding a fish and retrieved through that location. The best locations are behind large boulders or on the edge of a quiet pool adjacent to a riffle. Experimentation is necessary to determine whether a continuous retrieve or a crank-and-pause method will yield the best results.
Smallmouth appear to be more active surface feeders as mid-summer approaches and water levels recede. At this time there are many species of terrestrial insects common to the adjacent terrain that wind up struggling for freedom on the surface. Heavy hatches trigger increased surface activity as bass feed actively on these easily-caught prey.
Fishing Turbid Water
The large watersheds of most Iowa smallmouth streams can cause rapid deterioration of water clarity after heavy rainfall. An angler must be prepared for the inevitable situation when turbidity limits clarity to 6-inches or less. In these cases, spinner-baits, especially those with sonic blades, are the better lures.
Another option when faced with turbid water conditions is to use lures of colors most easily seen under low light conditions. Best colors include chartreuse, white, and yellow or lures with silver or gold reflecting flakes.
When one is selecting a lure, the depth at which bass are located must be considered. In hot weather during July and August, smaller fish will often be active in one to two feet of depth immediately above and below rock riffles. However, larger bass will more often frequent structures extending into deep holes. Crank-baits that hug the bottom in four to five feet of water or leadheads bounced along the bottom will be most successful in catching quality-sized fish.
In spring and fall, with cooler water temperatures and decreased intensity of the sun, even larger bass will be found near shallow structures. Spinner-baits, which ordinarily are fished only one or two feet below the surface, become very effective in these conditions. Shallow-running minnow type crank-baits are also good.
Weather conditions have some bearing on how actively smallmouth react to a lure presentation. As a cold front approaches, bass often become extremely active. They can be very non-selective in feeding and will strike at almost any lure presented. But once the front settles in, the fish retreat deeper into structure. During this period, accurate lure presentation becomes of utmost importance in coaxing a fish to strike. Lures must be placed extremely close to the fish, yet not so close that the fish will be spooked.
Bait Selection for Streams
So far little has been mentioned about the use of live bait. Natural baits, such as crawfish, minnows, hellgrammites, and nightcrawlers that are fished properly can trigger a response when all else fails. These baits, threaded on a No. 6 or 8 hook and weighted by a small split shot, can be cast or drifted into the deeper holes with little difficulty. When a smallmouth picks up a crawdad, the first impulse is immediately to set the hook. This action usually results in rebaiting for another try. Smallmouth normally carry the prey for a short distance in their jaws prior to ingestion. Patiently waiting for the fish to stop its run, then reeling up the slack and setting the hook yield much better results.
The patient method also applies when using nightcrawlers. The fish must be given time to suck the entire bait, hook and all, into its mouth. This is especially true when using a whole nightcrawler hooked only through the collar or just in the tail.
When one is using minnows, shiners, or hellgrammites, the opposite applies. An angler can usually set the hook immediately and have success.
Catch and Release
Proper handling of the fish when landing is extremely important, because of the implementation of a 12-inch minimum length limit on smallmouth in Iowa streams, which requires the release of all sub-legal fish. The increased emphasis by many anglers on catch and release angling also adds to this number. Releasing a fish will do nothing to sustain the fishery if it is roughly treated and the fish dies later. Playing the fish for longer than is necessary to land it places an unnecessary physiological stress on it and lessens the odds for survival. Dragging the fish up on the stream bank instead of placing a thumb in the lower jaw and grasping firmly also causes undue injury. Scraping the protective mucus from the sides of a fish jeopardizes its resistance to bacterial infection and fungal growth.
Mishandling of the fish while removing the lure or hook can also increase mortality. The lure must be carefully removed while firmly gripping the fish by the lower jaw. Deeply set hooks must be cut off to dissolve. Release of unharmed fish will help maintain the quality of one of our most exciting fisheries.
Only about a half-dozen lakes in Iowa consistently yield catches of smallmouths, and all of these are natural lakes. Two lakes, Spirit Lake and West Lake Okoboji, have the best populations, and each year produce several record-sized fish.
Most lake smallmouth bass are caught during early spring or late fall. In the spring soon after ice out and while the water temperature warms, smallmouth move from deep to shallow water. This event usually occurs between mid-April and mid-May. Bass inhabit the rocky points and flat rocky areas that will soon serve as their spawning sites. During this pre-spawn period, fish are most often found in 4 to 12 feet of water.
Lure Selection for Lakes
Smallmouth feed ravenously during pre-spawn. Most successful methods are very similar to those used for pre-spawn walleye. Leadheads are cast and retrieved along the rocky shoreline and points. Since water depths fished are relatively shallow, only lightweight jigs, one-eighth to one-quarter ounce in weight, are best. Many smallmouth anglers prefer hair dressed jigs this time of year in white, blue, purple, and combinations of these colors. To get the favored combination, fishermen often tie their own leadheads.
The other leadhead dressing often used in pre-spawn is a plastic body twister. Colors in purple, yellow, and white are preferred. With either the hair jig or the twister, the hook can be tipped with a minnow without affecting the action, and it will often result in better fishing success.
While leadhead presentation is important at all times, when the water temperature is 48 degrees F to 55 degrees F, the colder temperatures affect the reaction time of a fish to a lure. Slow retrieves with a pumping motion so the jig bounces along the rocky shoreline habitat will improve your chances of catching a smallmouth.
Toward the end of pre-spawn, small crank-baits will provide action. The 2-inch size lure is preferred because smallmouths select relatively small-sized food items. Crayfish colored crank-baits seem to be the best, particularly on the numerous rocky land points in West Lake Okoboji.
Lake Angling Techniques
Weather conditions in pre-spawn have some impact on fishing success, but probably not as severe as in summer. Smallmouths inhabit the shallows even during inclement weather as they "feed up" in preparation for spawning. The worst condition to deal with is the high winds that are commonplace during this period. Severe wind blowing over spawning shoals will force smallmouths into deep water, making them more difficult to locate.
On bright days smallmouths are reluctant to move into the shallows, except in early morning and evening. The fish will linger close by in mid-day and usually can be found by fishing several feet deeper.
During summer, smallmouths disperse and are much more difficult to locate. Fishing pressure is usually targeted toward other species during this period, with angling interest in smallmouth renewed in the fall. Some persistent anglers are able to locate smallmouth bass even in hot weather by carefully working submerged rock reefs, often using live bait. Smallmouth inhabit eight to ten feet of water on the top of the reef, particularly in low light periods. If the fish are not near the reef, fish the drop-offs where the depth increases quickly to 20 feet or more. Soft-shelled crayfish are one of the favorite baits in summer, fished on a number-8 hook and using just enought weight to carry the bait to the bottom.
One of the best lures for summer fishing is a crank-bait; those resembling the color, size, and action of a crawfish are preferred. When using crank-baits in water deeper than 10 to 12 feet, a split shot must be placed in front of the lure in order to make the lure run deep.
Fall is one of the best fishing periods for smallmouth bass. The fish are closely associated with shallow rock reefs in 10 to 15 feet of depth. Crank-baits are still the preferred lure, but they must be deep-diving models. Leadheads run a close second, and at this time of year they should be tipped with a minnow. Minnow shaped plugs that imitate bait-fish are the third choice for fall smallmouth.
Whether one is fishing for smallmouth in stream or lake, the experience of attempting to land this trophy quickly makes a believer out of even a seasoned angler. Few fishermen, who have enjoyed this experience, fail to praise the smallmouth for its tenacity. Following such an experience, few anglers fail to plan a return trip to take on again this superb game fish.
*Mayhew, J. (editor). 1987. Iowa Fish and Fishing. Iowa Department of Natural Resources, Des Moines, Iowa. 323 pp.