Please select from one of the listed crappiei articles to view more information.

Black Crappie

Black Crappie

2007/11/19 07:05:59.726 US/Eastern

By Robert Adams

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Actinopterygii
Order: Perciformes
Suborder: Percoidei
Family: Centrarchidae
Genus: Pomoxis
Species: Pomoxis nigromaculatus

Geographic Range

The native range of Pomoxis nigromaculatus is the freshwaters of central and eastern North America. It has further been introduced to freshwater lakes of the Pacific coast and Canada due to its popularity as a sport-fish and its durability. (Mettee et al. 1996, Sigler et al. 1987)

Biogeographic Regions:
nearctic (introduced , native ).


Pomoxis nigromaculatus favors clear, warm, highly vegetated, moderately acidic, and non-turbid waters of lakes and rivers in its natural range. (Sigler et al. 1987)

Aquatic Biomes:
lakes and ponds; rivers and streams.

Physical Description

250 to 900 g
(8.8 to 31.68 oz)

Black crappie adults vary from 130-381 mm in length. The average weight varies from 0.25-0.90 kg. Black crappie are a monomorphic species characterized by 7-8 dorsal spines which are stepped in length, an upturned (S-shaped) snout, symmetrical dorsal and anal fins, a wavy light and dark pattern on non-paired fins, and a mottled (spotty) color pattern.

There are color variances among populations of black crappie. Age, habitat, and breeding are all determinants of the intensity and patterns of mottling: juveniles tend to have less pigment and pattern than adults; those black crappie living in clear, vegetated water have strikingly bolder patterns than those living in turbid, murky water; and breeding males have a darker head and breast than normal populations. (Jenkins et al. 1994, Sigler et al. 1987, Trautman 1981, Becker 1983, Smith 1979, Robison et al. 1988, Mettee et al. 1996)

Some key physical features:
bilateral symmetry .


Both sexes of Pomoxis nigromaculatus reach their sexual maturity by the age of two and usually live seven years. The spawning temperatures and months vary due to the wide natural range of black crappie, but the temperatures are usually from 58� to 68� Fahrenheit, corresponding to the months of April through June.

Before the spawning period, black crappie form schools that migrate to shallower water to feed. It is during schooling when the male crappie sweeps out the nests and attracts the female. The female black crappie is very fertile. She may spawn several times during the period with several males, bearing 10,000-200,000 eggs (variation related to size and age of female). Once the eggs are in the nest, it is the male's responsibility to guard the nest until the young can freely swim and feed. (Jenkins et al. 1994, Sigler et al.1987, Becker 1983, Robison et al. 1988, Mettee et al. 1996)


Pomoxis nigromaculatus are schooling fish. During the day, they can be found in deep water around fallen trees, weed beds, and other submerged structure. They move toward shore to feed several times a day, mainly at dusk and dawn. During the spawning period, they concentrate in shallow, warm water. In the winter, black crappie do not go into semi-hibernation, however they may move to deeper water.

As fingerlings, P. nigromaculatus are preyed upon by many animals. Perch, walleye, bass, northern pike, and muskellunge are the fish that pose the most threat to black crappie young, but the large anal and dorsal fins allow the adults some protection against these predators. Other animals such as the great blue heron, american merganser, snapping turtles, otter and mink can prey upon black crappie young and sometimes adults as well. There are a few parasites of the black crappie, which include many protozoa, trematodes, cestodes, and nematodes. (Sigler et al. 1987, Becker 1983)

Key behaviors:
natatorial ; motile .

Food Habits

As a juvenile, Pomoxis nigromaculatus feeds mainly on microscopic prey such as Cyclops, Cladocera, and Daphnia.

As an adult, Pomoxis nigromaculatus is a mid-water omnivore that feeds in vegetation and open water. Its numerous gill rakers allow it to consume planktonic crustaceans; however aquatic insects, minnows, and fingerlings of other species comprise its main diet. Dawn, noon, dusk, and midnight are peak times for black crappie feeding.

Much of the success of the black crappie is attributed to its ability to eat foods of all forms, at all times of the year. (Becker 1983)

Economic Importance for Humans: Negative

Since black crappie are omnivorous, they eat the fingerlings of many other fish, including those of its predators: pike, walleye, muskellunge, etc. If there are no predators for smaller fish such as sunfish, perch, and black crappie, the lake will become over populated. This tendency for black crappie to overpopulate its community, not only stunts its species' population growth, but also those of other species due to an increase in competition. (Becker 1983)

Economic Importance for Humans: Positive

Pomoxis nigromaculatus is a popular sport fish: the flesh is white and flaky; due to its wide variety of prey, fisherman are able to use many methods to catch them; they can be caught at all times of the year, which especially benefits fishermen who enjoy ice-fishing; high populations allow for many to be caught; and their aggressiveness allows for a good fight. (Sigler et al. 1987, Becker 1983)

Conservation Status

IUCN Red List: [link]:
Not Evaluated.

US Federal List: [link]:
No special status.

CITES: [link]:
No special status.

State of Michigan List: [link]:
No special status.

Pomoxis nigromaculatus is not among those species in the endangered species list; however, to avoid over-fishing, daily limits are used.


Robert Adams (author), University of Michigan.
William Fink (editor), University of Michigan.


Becker, G. 1983. Fishes of Wisconsin. Madison, WI: University of Wisconsin Press.

Jenkins, R., N. Burkhead. 1994. Freshwater Fishes of Virginia. Bethesda, MD: American Fisheries Society.

Mettee, M., P. O'Neil, J. Pierson. 1996. Fishes of Alabama and the Mobile Basin. Birmingham, AL: Oxmoor House, Inc..

Robison, H., T. Buchanan. 1988. Fishes of Arkansas. Fayetteville, AR: Universty of Arkansas Press.

Sigler, W., J. Sigler. 1987. Fishes of the Great Basin. Reno, NV: University of Nevada Press.

Smith, P. 1979. Fishes of Illinois. Urbana, IL: University of Illinois Press.

Trautman, M. 1981. Fishes of Ohio. Columbus, OH: Ohio State University Press.

2007/11/19 07:06:01.230 US/Eastern

Article Source:

For additional information, please visit

Crappie Advice from Fish Resource Dot Com

Introduction to Crappie

Other names: speckled perch, calico bass, grass bass, speckled bass, speckled perch, strawberry bass, oswego bass, sacalait, sacalaitt, barfish, crawpie, bachelor perch, papermouth, shiner, moonfish.

Black Crappie

Crappies, or calico bass, are a widespread and popular pan fish. There are two types of North American crappiei - the black crappie (Pomoxis nigromaculatus) and the white crappie (Pomoxis annularis). Both varieties weigh about four to five pounds when mature and range from southern Manitoba south to the Mexican border.

Anglers will be happy to hear that fishing for crappies and eating the fillets actually helps create a healthy crappie population by preventing overcrowded areas of growth-stunted fish.

Crappie Distribution

Introduced all over North America, the original territory of the crappie likely spanned from Virginia to Florida, west to Texas, and from the St. Lawrence / Quebec / Great Lakes and Mississippi River basins south to the Mexican Gulf.

Crappie Habitat

Black crappie are found near vegetation in deeper/clearer/cooler water than white crappie. White crappie live in creek pools, slow-moving sand-and-mud bottomed streams and rivers, and shallower water in lakes. Crappie form schools and feed together near vegetated drop-offs, underwater debris and structure of all types.


Crappie are deep-bodied and laterally compressed fish with protruding lower lips and a depression on the forehead above the eye.

White Crappie

Count the dorsal fin spines to distinguish between the white and black crappies: black crappies have seven or eight, and the white crappie generally has only six.


Crappie are a silvery olive with dark spots arranged in several vertical lines across the body of the fish.

Breeding white crappie males change to a darker body colour and are often mistaken for black crappies; black crappie males, however, do not change colour during the spawning season.

Size of Crappie

Crappies usually weigh about 2 pounds or less but may reach 5 pounds.

Feeding Habits of Crappie

Crappies especially feed in the evenings and early mornings, on zooplankton, insects, crustaceans, fish, larvae and on small shad, minnows and sunfish. Crappie are known to eat their own young as well as other fish fry, and feed actively throughout the winter.


Spawning occurs in late spring or early summer when the water temperature reaches 65ºF. The female lays up to one hundred fifty thousand eggs in a shallow depression scraped on the floor in less than six feet of water. The parent fish protect the eggs until the fry hatch in less than a week. However, the parent fish are the first to feed on the fresh fry. The surviving fish grow two or three inches by the end of their first year, and some are nine inches long by the end of their second.

Mature crappies (2 to 6 years old) eat their own young, causing cycles of severe population decline. When few mature crappies populate the lakes, most of the young fish survive and the population thrives for the next few years. In small or overcrowded lakes crappies experience stunted growth. Many biologists support an unlimited bag limit for crappies to promote a healthy fish population.

Spring Crappie Fishing Techniques

During the spring spawn, fish the concentrations of crappies in the shallows. Use a sensitive fiberglass crappie pole with a bamboo handle instead of a reel. Often, anglers do not feel when a crappie has taken the bait. Gently lift and drop the line continually to hook these gentle biters. To find the fish, tie a No. 4 hook to the line, attach a small slip shot above the hook, and add a bobber somewhere on the line so that the hooked minnow swims near the bottom. Hook the minnow lightly under its back fin and direct it through the shallow reeds and underwater brush piles. Try inch-long minnows early in the season, switch to larger minnows as the season progresses, and use jigs in the summer.

Each body of water is different, but generally the north side of the lake warms more quickly than the south in early spring. Try the north shallows first, then after the spawn try the submerged reedy islands in the body of the lake. Map out the warmer waters of the lake to find the early spring crappies.

Summer Crappie Fishing Techniques

When the waters warm in the summer, crappies move to deeper water that has the same bottom cover as the shallows they frequent. Outside of the shallow bays, many fish gather together on the deep side of a drop-off in water six to twelve feet deep. Other places to look for elusive summer crappies are at the mouths of slow, narrow channels, at areas less than a hundred yards out from a fast-moving bay opening, or in the shallows at dawn and dusk where the crappies return to feed until early summer.

Search for large obstructions or rock piles in deep water, as well as weed beds and brush piles. Carefully fish rocky shelves ten to fifteen feet deep that have rock piles or a submerged tree. Since summer crappies follow schools of smaller fish, anglers should make note of where the smaller fish like to feed.

Summer crappie fishingi gear usually consists of an ultra-light spinning outfit or fly rod with a spinning reel. Slowly work a small (1/32 or 1/64 of an ounce) jig in white or yellow with a gold-wire hook. Yellow 1/4 ounce spinner baits work well for bigger crappies. Some anglers add a bobber to the line to maintain the jig at a desired depth. Anchor or drift in ten feet of water above the underwater structure and slowly jig the lure. Slowly reel the jig while only slightly twitching the rod tip, and tug the line at any hint of a bite.

Fall Crappie Fishing Techniques

In the fall, crappies move back to the shallow bays. Use the fiberglass pole and live minnows, or try ultra-light spinning tackle, a plastic casting bubble, and No. 6 or 8 artificial trout nymphs fished 40 inches below the bubble. Retrieve the lure at a pace fast enough to keep the line tense.

In man-made lakes the water level often fluctuates. The fish stop biting when the water level drops, but often reanimate with a vengeance once the levels rise. During an hour or so when the water rises, fish the shallow brushy areas with any bait or lure.

Experiment to find the right combination of depth, bottom cover and water temperature for clusters of crappies. Check new brush piles for big crappies and largemouth bass, and if the crappies aren't biting, try forcefully beating the pile with an oar or stick and then fish the pile again.

Winter Crappie Fishing Techniques

In the winter, catch the active crappie using light ice-jigging equipment with 4 pound-test monofilament line a No. 4 hook. Use a live 2-inch minnow bait on a No. 4 hook and one split shot: place a split shot one foot above the minnow (hooked lightly beneath its back fin) and fish the setup at varying depths. Prepare for a very gentle bite, then set the hook and reel in the tasty, white, flaky meal.

Crappie Management Plan 02-28-2002



February 28, 2002 Prepared by Tim Burnley D. Colton Dennis Jeff Farwick Dean Smith Don Turman Drew Wilson Approved by: Mike Gibson, Chief of Fisheries ARKANSAS GAME & FISH COMMISSION CRAPPIE MANAGEMENT PLAN MISSION STATEMENT: The goal of crappiei management is to provide quality crappie fishingi. Management efforts towards improving recreational crappie fishingi will be optimized within the context of a multi-species fishery by accurately characterizing crappie population density and structure and enhancing crappie populations through harvest regulations, stocking, and habitat improvement. OBJECTIVES: 1. Develop standardized sampling methodology for evaluating crappie populations. 2. Develop a set of biological criteria for identifying what a model crappie population in Arkansas should resemble based on standardized sampling procedures to manage both black and white crappie populations collectively. 3. Develop a Crappie Stock Assessment to provide a standardized means for fisheries managers to make objective evaluations of population structure and population trends over time. 4. Develop a set of biological criteria that would determine when or if harvest regulations would be appropriate for improving crappie population structure. 5. Develop guidelines and evaluate effectiveness of crappie supplemental stockings. 6. Evaluate need for stocking forage species such as threadfin shad when crappie growth is limited. 7. Evaluate need for stocking predator species such as saugeye when crappie overpopulation and stunting occurs. 8. Assess crappie habitat needs in Commission-owned and Federal water project lakes and implement appropriate habitat improvement projects. 9. Exploit opportunities to influence water management policy and operational features on Federal water project lakes to improve crappie habitat.

Information Provided by Arkansas Game and Fish Commission

Table of Contents


Information Provided by Arkansas Game and Fish Commission

1 - Executive Summary

Crappie collectively are the most sought after sport fish among senior resident anglers (44%), and second to bass (largemouth and spotted) among resident (34%) and on-resident (25%) anglers in Arkansas (Duda et al. 2000). Combined, resident and non-resident anglers spend an estimated $92.6 million annually fishing for crappiei in Arkansas. Because of high angler interest and the significant contribution to the State’s economy, the Arkansas Game and Fish Commission has intensified its efforts towards developing a species plan to optimize management efforts and enhance the quality of recreational crappie fishingi by characterizing and improving crappie population structure.

A standardized sampling methodology for sampling and evaluating crappie populations was developed using trap nets. Trap netting will be conducted a minimum of 30 net-nights per month from September through November in an effort to collect sufficient numbers of crappie to allow population size and age structure analysis.

A set of biological criteria was developed to define a model crappie population in Arkansas based on standardized sampling results. Objectives for the five population parameters of density, growth, age structure, size structure, and recruitment were established by examining trap net data from fifteen Arkansas lakes. Lakes varied from oxbows to large Corps of Engineer impoundments and from relatively clear and infertile waters to very productive lakes with dense algae or plant growth.

A good crappie population has a high density of desirable-size fish available for angler harvest. Further, it will have adequate and consistent recruitment accompanied with sufficient growth to compensate for harvest.

An optimal crappie population in Arkansas will exhibit a growth rate of 201-mm to 275-mm (8-11 inches) at Age-2+, have a size structure (percent > 250-mm) above 30%, and show consistent recruitment. These metrics are minimally sufficient to describe a good crappie population. Age structure, growth, and mortality estimates are needed to determine the suitability for enacting minimum length limits and/or other harvest regulations.

A crappie stock assessment was developed based on estimates of density, growth, age structure, size structure, and recruitment. Values for the five parameters were established by examining trap net data from Arkansas lakes, and highest values were assigned to optimum measurements of each parameter. Values assigned to each population parameter were summed to give an overall rating for the crappie population condition. The Crappie Population Assessment should provide a standardized means for fisheries managers to make objective evaluations of population structure and population trends over time.

A set of biological criteria was developed to determine when or if harvest restrictions would be appropriate for improving crappie population structure. Management strategies based on growth and mortality rates, and age and size structure include adjusting crappie creel and length limits, management of predators, lake fertilization, stocking, and control of aquatic vegetation and turbidity.

Angleri preference is an important consideration when minimum length limits are being examined as management strategies. The use of population modeling programs will be used to predict long-term effects on crappie harvest prior to implementation of minimum length limits. Due to the various growth and natural mortality rates of crappie populations across the state, statewide length limits may be detrimental and result in substantial reductions in yield to some fisheries. Therefore, statewide length limits are not a recommended management strategy for Arkansas crappie populations.

Guidelines for crappie supplemental stocking were developed, in which stocking rates are determined by lake size. New lakes have the highest priority for crappie stockings. Supplemental stockings in other lakes will be based on technical analysis of cove rotenone population samples and/or trap netting and social needs relevant to the fishery. Lakes over 4,050 ha, including Corp of Engineer impoundments, should be stocked through the nursery pond system. Crappie should not be stocked in lakes during years of high recruitment, since supplemental stocking is not likely to make a significant contribution to the naturally produced, strong year-class. Also, crappie should not be stocked in lakes where Age-0 to Age-1 mortality is high, because it is likely that supplemental stocking will have a similar high mortality rate due to poor conditions such as lack of adequate forage, habitat, or high predation. Environmental manipulation techniques such as lake fertilization, water level manipulation, and habitat improvement will be used in tandem with regulations and stockings to improve crappie populations where these techniques are appropriate. Habitat assessments are to be performed on Commission-owned and Federal water project lakes to determine crappie habitat needs. Feasibility plans are to be drafted and implemented to address these needs as budget and resources allow in an effort to improve crappie habitat statewide.

No management plan is complete without proper evaluation, and management strategies suggested in this plan should be appropriately evaluated after exploitation studies have been initiated, population modeling has been conducted, harvest restrictions have been imposed, or creel surveys have been completed. Evaluation of additional trap netting data using the Crappie Stock Assessment will yield further information regarding the effectiveness of the management plan.

Natural mortality rates of Age-0 to Age-1 crappie should be derived by fishery managers to assess where supplemental stockings will be most beneficial. Fishery managers should also re-evaluate current crappie minimum length limits on Arkansas lakes using population modeling programs. Other sampling techniques such as using larger 8’ x 8’ or 6’ x 6’ trap nets and spring/fall electrofishing should be explored where standard trap net gear has been ineffective at sampling the crappie population.

Handling and hauling mortality of crappie must be estimated and reduced by hatcheries to minimize post-stocking mortality. Acceptable marking techniques for identification of stocked crappie also need to be investigated. Once a desirable marking technique is accepted, future contributions of stocked fish to year-classes can be evaluated.

A Crappie Recruitment Model is needed to determine what variables are having the greatest impact on crappie recruitment in Arkansas waters. The model would potentially help fishery managers identify those problems in reservoirs where corrective management could be applied, and would also help in predicting missing year-classes and thus, supplemental stocking guidelines on an annual basis.

Finally, the purchase and replacement of boats, motors, trap nets, funding for exploitation/tag reward studies, and continued workshops and application of fish population modeling is needed for successful implementation of this plan.

Information Provided by Arkansas Game and Fish Commission

2 - Introduction

Both black crappiei (Pomoxis nigromaculatus) and white crappie (P. annularis) are found throughout Arkansas (Robison and Buchanan 1988). Both species prefer quiet waters, and are almost always found near cover such as brush piles, tree tops, standing timber, and aquatic vegetation. Black crappie prefer cooler, deeper waters and seem to dominate in clear, vegetated, acidic waters, while white crappie tend to dominate in eutrophic (richer), more turbid, alkaline waters.

Crappie collectively are the most sought after sport fish among senior resident anglers∗ (44%), and second to bass (largemouth and spotted) among resident (34%)and non-resident (25%) anglers in Arkansas (Duda et al. 2000). Questionnaire results also indicated that a large percentage of anglers (62% of senior residents, 48% of residents, and 43% of non-residents) choose to consume the different species of fish they catch (Duda et al. 2000).

In 1996, resident anglers spent $191.3 million and non-resident anglers spent $110.4 million fishing in Arkansas waters (Maharaj and Carpenter 1997). Combined, resident and non-resident anglers spend an estimated $92.6 million annually fishing for crappie in Arkansas. Because of high angler interest and the significant contribution to the State’s economy, the Arkansas Game and Fish Commission has intensified its efforts towards developing a species plan to optimize sampling and management strategies towards improving the quality of recreational crappie fishingi.

For years, biologists believed lakes with large numbers of undersized crappie were the result of overpopulation and stunting (Goodson 1966; Ming 1971). As biologists began to look more closely at crappie age-and-growth, they often found over-harvest instead of over-population (Webb and Ott 1991). Colvin (1991) reported over-harvest of crappie in a large Missouri reservoir. However, this is not always the case as Reed and Davies (1991) recommended against size restrictions to protect the crappie fishery from over-harvest, because high natural mortality would have nullified the benefits of a delayed harvest.

Past crappie management in Arkansas was seldom based on well-defined objectives developed from the three rate functions of recruitment, growth, and mortality, which reflect crappie abundance and size structure. Often, crappie received little or no direct management. A standardized approach to characterizing the state’s crappie 6
populations was needed to provide reliable information. A research team was formed in 1994 to develop criteria to best characterize crappie population structure and optimize
management efforts. Fifteen lakes were sampled with trap nets between 1989 and 1993 to gather data to develop this plan (Table 1). Lakes varied from oxbows to large Corps
of Engineer impoundments and from relatively clear and infertile waters to very productive lakes with dense algae or plant growth.

Successfully managing crappie populations requires understanding and manipulating processes controlling recruitment. Recruitment is the number of crappie surviving their first year of life, and is influenced by spawning success, environmental conditions (temperature, food availability, water level fluctuation, turbidity, etc.) and
predation on young-of-the-year (YOY) crappie. Arkansas’ lakes undergo fluctuations in water levels, temperature, turbidity and organic inputs. These factors greatly affect the success of crappie spawns and produce natural variations in fry production. Under proper circumstances these variations are evident later in recruitment and eventually in
age structure.

Cyclic and highly variable recruitment is a principal management problem in crappie fisheries, which generally produce strong year-classes every 3-5 years (Swingle and
Swingle 1967). Results from Allen and Miranda’s (1997) crappie age-structure population model suggested that a specific combination of stock abundance and environmental conditions produced cyclic recruitment in crappie populations. These factors may act in combination resulting in high recruitment when stock abundance is low and environmental conditions are favorable, and low recruitment when stock abundance is high and environmental conditions are unfavorable. In addition, modeling suggested that even with favorable environmental conditions, production of a strong year class might lead to reduced or only average recruitment in subsequent (1-5) years.

The predator population also affects fry/juvenile mortality and subsequent recruitment. We speculate that a high-density bass population results in low crappie recruitment due to intense predation (high natural mortality), in which surviving crappie are fast growing and reach large size. Many fishermen would prefer this situation to catching numerous smaller crappies (AMRA 1988). An example is Bear Creek Lake, which holds a dense population of 250mm-325mm (10-13”) largemouth bass, and shows low crappie recruitment and rapid growth with average size of 320-mm (12.5”) at age 2+. In contrast, Lake Greenlee has low bass density and shows crappie to be

(∗ denotes anglers who have purchased an Arkansas Senior Citizen (65+) fishing license)

overpopulated, slow growing, and seldom reaching more than 150-mm (6”) in length as adults.

Dense predator populations have been shown to be inefficient in controlling YOY crappie when turbidity levels are high or thick vegetation is present. Channel scar lakes or shallow lowland lakes are perhaps Arkansas’ most fertile lake type and often have dense vegetation and/or turbid water used as cover by many YOY fishes. These lakes show good to high recruitment values and low mortality of YOY crappie, which results in low growth rates. Recruitment must be controlled to properly manage these lakes. Added fishing pressure and relaxed limits may not be sufficient to control overpopulation. Control of vegetation and turbidity may provide an answer.

In lakes containing moderate densities of largemouth bass and low crappie density, natural fluctuations in crappie production show up as inconsistent recruitment and missing year classes. Lakes Beaver, Bob Kidd, Nimrod, and Horseshoe show large variations in age structure due to inconsistent recruitment. The most appropriate management strategy in these situations may be to manage the habitat (water level,
cover, fertilization) to enhance spawning success and recruitment.

Harvest regulation is one possible way to influence crappie populations when exploitation (angler harvest) is high. However, only under conditions of rapid crappie growth and low natural mortality will minimum length limits improve yield (average weight of fish harvested) in crappie populations. Prior to the implementation of minimum length
limits, population-modeling programs should be used to predict long-term effects on the crappie population. Modeling results can be evaluated by subsequent field data
collections. Knowledge of angler preference when minimum length limits are being investigated should also be an important consideration for fishery managers in the
decision-making process.

Information Provided by Arkansas Game and Fish Commission

3 - Crappie Population Evaluation

3.1 - Standardized Sampling Procedures

Trap net samples are described as the most efficient and precise means of sampling crappiei. Boxrucker and Ploskey (1988) found trap nets to have a higher catch per unit effort (CPUE) and lower within season variability than either electrofishing or gill netting, and were the only types to adequately sample YOY crappie. Fall trap netting best represented population structure. McInerny (1988) found age and size structure of black crappie from fall trap netting similar to that harvested by fishermen during the same season. Miranda et al. (1990a) found a significant correlation between white crappie abundance from spring trap netting and springtime angler harvest per hour.

The primary objective of trap netting is to collect sufficient numbers of crappie to allow population size and age structure analysis in lakes with significant crappie
fisheries. Trap netting may also be used to collect fish for mark-recapture population and exploitation estimates.

Temporal variations in size and age structure of crappie are evident within our fall trap net samples in Arkansas. A higher percentage of YOY are caught in early fall, while
larger, older fish are caught in late fall. Better estimates of population parameters can be obtained by sampling throughout the fall. All fish will be aged by examining otoliths. This method results in less error and variability than the scale method (Boxrucker 1986).

Information Provided by Arkansas Game and Fish Commission

3.2 - Gear Specifications

Trap nets are constructed with two (2) 3’ x 6’, 5/16” diameter, steel frames with center braces and four (4) 2.5’ diameter hoops of 3/8” steel. The 3’ x 6’ frames are 30” apart, and the first hoop is 32” from the second frame. The hoops are 24” apart. The second 3’ x 6’ frame has a slit throat and the first hoop has a 6” throat. The net material is 1/2” square NO.105 L knotless nylon, netset treated. The cod end of the net has a string closure with a 5’ No. 5 braided nylon string.

The leads are 1/2” square No. 105L knotless nylon hung 14 meshes per foot on No. 60 nylon twine, netset treated with 2” x 1.5” cork floats spaced at 3’ intervals and 1.5 oz. weights spaced at 2’ intervals. The leads are 50’ in length and 3.5’ deep with the exception that shorter leads can be used near steep drop-offs. Leads are permanently attached to the second 3’ x 6’ frame center brace.

Alternatively, Miranda et al. (1996) reported that floating trap nets with larger frames, and longer and deeper leads than the standard 3’ x 6’ frame with 50’ lead may be necessary in larger, deeper reservoirs where catch rates are low. These large 8’ x 8’ frame floating trap nets with 200’ leads resulted in larger sample sizes with moderate
sampling effort when fished in habitats that previously were not sampled effectively by standard trap net gear.

Although the larger 8’ x 8’ frame net caught more crappies than the standard net, fishing the net can sometimes be problematic. The net is bulky, and because of its size
and weight can be difficult to handle when wet. Wind and wave action can cause the nets to be disabled, especially in open-water sets. The large nets are also at risk floating in open waters where they are likely to be encountered by boaters.

Isaaks and Miranda (1997) developed a smaller 6’ x 6’ frame floating trap net with a 150’ lead that is easier to handle than the larger 8’ x 8’ nets. The 6’ x 6’ net resulted in catch rates that were lower than the 8’ x 8’ net, but significantly greater than standard nets. Therefore, the 6’ x 6’ floating nets may be a compromise between the standard 3’ x 6’ nets and the more cumbersome 8’ x 8’ floating nets.

Information Provided by Arkansas Game and Fish Commission

3.3 - Sampling Effort

Trap netting will be conducted during the months of September, October and November when water temperatures are between 16 - 26 degrees C (61 – 79 °F). Minimum effort is 30 net nights per month, or 150 crappiei greater than Age-0 for lakes less than 810 hectares (2000 acres), or 250 crappie greater than Age-0 for lakes 810 hectares or larger.

Information Provided by Arkansas Game and Fish Commission

3.4 - Site Selection

Nets should be set perpendicular to crappiei movement. Suggested areas include gradually sloping lake bottoms at the mouths of coves, off points, or areas adjacent to old river channels. Net sets in or near standing timber or where the leads break over a sharp drop-off should be avoided. To reduce variability over time, the same locations should be netted from year to year. Global Positioning Systems (GPS) can also be used to record net site locations that are consistently more productive.

Information Provided by Arkansas Game and Fish Commission

3.5 - Net Set Procedures

Nets should be set at least one hour prior to sunset. If nets are left in the same location, then they should be checked at the same time each day if possible. Also, trap nets should not be fished at the same set more than two nights in succession.

All crappiei collected are differentiated by species, and total length and weight for each fish recorded. When large numbers (>200) of fish <80mm are collected, subsamples of 25% by number are permitted.

Otoliths will be removed for age determination from a minimum of 10 fish per 25-mm (1-inch) length group for each species. Otoliths will be read using a dissecting microscope or microfiche. A micrometer is optional, but is required for back calculations. All trap net sampling data including information obtained from otolith readings will be recorded and processed using the Fisheries Division trap net software, currently being developed.

Information Provided by Arkansas Game and Fish Commission

3.6 - Limitations

There are several problems inherent to this sampling scheme. These problems should not influence recommendations; however, fish managers should be aware of these limitations and make changes in sampling schemes when necessary.

Crappies are growing during the sampling period from September through November. Differences in lengths during this period may obscure length-frequency histograms and length-at-age determinations. Sample variance of length-at-age will increase with the width of the sampling window. Growth during the sample period is especially critical for younger age groups. This may cause problems when comparing population statistics from year to year and make it more difficult to identify changes.

Young of the year crappiei are typically caught in higher proportions earlier in the fall, and larger, older crappie are generally caught later in the fall. This makes it
necessary to sample over the entire 3-month period to obtain a representative sample. Should the minimum number of crappie be caught early in the sampling season, the older component may not be represented in proportion to their abundance in the population.

Additionally, the percentage of crappie of a given age within a size group can only be estimated within 10%, if 10 fish per size class are aged. When more accuracy is required, more or all fish should be aged. Sampling from September through November, calculating length at a standard age (back calculations), and aging all fish can reduce these problems.

Information Provided by Arkansas Game and Fish Commission

4 - Crappie Population Assessment

Developing appropriate objectives for population parameters combined with standardized sampling procedures are vital to achieving effective fisheries management (Anderson, 1975). In the last few years, considerable attention has been given to the use of structural indices to describe and classify population structure.

Colvin and Vasey (1986) developed a method of assessing white crappiei populations in Missouri based on fall trap netting. Their system is based on standard point values assigned to estimates of density, growth (length-at-age), age structure, size structure, and recruitment calculated from fall trap net samples. A 0-10 rating is assigned to each of the five population parameters. The five scores are then summed to give an overall index of population condition. This assessment is currently used to evaluate crappie population structures in Missouri (M. Colvin, Missouri Department of Conservation, personnel communication).

A primary objective of the Crappie Management Plan was to develop a stock assessment index to evaluate crappie populations in Arkansas (Table 2). Missouri’s Stock Assessment Index was selected as a model from which to begin. The Missouri index, however, was developed for large reservoirs and white crappie populations only.
Arkansas has both species of crappie existing in large impoundments as well as small lakes. Therefore, the Missouri Stock Assessment Index was adjusted to accommodate
for these differences. Trap net data collected between 1989-1993 from fifteen Arkansas lakes, which varied from oxbows to large Corps of Engineer impoundments, were used to generate the model.

Arkansas’ lakes contain mixed populations of white and black crappie that must be managed as a group for regulatory simplification and so are combined for stock
assessment. Values (1-10) are assigned for ranges of five population parameters (density, growth, age structure, size structure and recruitment) calculated from fall trap
net samples. Highest point values are assigned to optimum measurements of each parameter. Because crappie density values varied greatly among the fifteen lakes sampled, and recruitment values are sometimes a poor indicator of actual Age-0 abundance, these two parameters have been weighted disproportionally in the assessment. Pointi values assigned to each population parameter are summed to give an overall rating for the crappie population condition. However, the values of the individual parameters are more useful for management purposes than the final assessment value.

The Crappie Population Assessment (Table 2) should provide a standardized means for fisheries managers to make objective evaluations of population structure and population trends over time in specific lakes. The assessment can also be used to compare indices between similar lake types such as Bull Shoals and Norfork.

Information Provided by Arkansas Game and Fish Commission

4.1 - Characteristics of a Good Crappie Population

A good crappiei population has a high density of desirable-size fish available for angler harvest. Further, it will have adequate and consistent recruitment accompanied with sufficient growth to compensate for harvest.

Information Provided by Arkansas Game and Fish Commission

4.2 - Density

Density is a function of recruitment and mortality. Catch per trap net-night of Age-1 and older fish in fall samples is used as an index of density. Age-0 crappies are excluded because trap nets do not sample Age-0 in proportion to their abundance and the presence of a large year-class could bias the sample.

Catch rates of 10 to 39 Age-1 and older crappie per net-night are considered optimal for our purposes. However, when sufficient forage is available and growth is good (mean length @ Age-2+ >250mm) higher densities are acceptable. Lower scores are assigned to the same catch per net night if growth is poor (mean length at Age-2+ <200mm).

Density, fish movement, weather conditions, and other factors influence trap net catch rates. Lake morphometry, water levels, presence of cover, etc influence capture efficiency. Catch rates may not always represent actual density. For this reason, several years of data are desired when analyzing crappie populations.

Population density influences the ratings of 2 other parameters. When densities of crappie are good (>20 Age-1+ and older per net-night), broader ranges of growth rates and size structure are accepted as desirable.

Information Provided by Arkansas Game and Fish Commission

4.3 - Growth Rate

Growth rate (mean length @ Age-2+) should be a good indicator of the availability of forage relative to crappiei abundance. Growth influences the size and age structure of a population and affects sizes of fish available for harvest by anglers. In a desirable population, fish should reach a minimum harvestable size in a reasonable period of time.

A good crappie population should have a growth rate between 201-mm (8”) and 275-mm (11”) at Age-2+. Current data shows Arkansas lakes are capable of growth rates within this range. Crappies above 225mm begin to add weight at a faster rate and are valued more highly by fishermen.

High growth rates (> 275-mm @ Age 2+) are associated with lower than optimal densities and age structure. However, higher growth rates are acceptable when density is high since an adequate forage base must be present to produce good growth. Poor growth (≤200-mm @ Age 2+) may be attributed to other trophic levels other than forage fishes, since crappie less than 150-mm (6”) forage primarily on plankton and aquatic invertebrates.

Growth influences the value assigned to the density rating. Density is rated higher when accompanied by good growth because density is not likely to be the limiting factor. Growth indirectly influences age structure by determining at what age crappie become vulnerable to angler harvest. Faster growing crappie become vulnerable to angling mortality sooner. Growth rate also influences the value of recruitment. Recruitment is rated higher when accompanied by good growth since density is not likely to be a limiting factor.

Information Provided by Arkansas Game and Fish Commission

4.4 - Age Structure

The age structure of a population is the result of recruitment and mortality (fishing and natural). Age structure is most useful as an indicator of mortality and may be our best indicator of recruitment, although it takes 1 to 2 years for a year class to show an effect. The management objective for age structure is at least 10% of the population comprised of Age-3 and older crappiei. Colvin and Vasey (1986) used percentage of Age-4 and older as an indicator of age structure for Missouri’s crappie populations. Boxrucker (1989) found the highest mortality of Oklahoma crappie to occur before Age-3. Current data indicates Arkansas’ annual mortality is similar, therefore, the percentage of Age-3 and older crappie (excluding Age-0 fish) is used to assess age

Higher assessment values are assigned to age structure when growth is good. An adequate forage base as indicated by good growth will allow for a higher density of older, larger fish. High age structure (>25% of adult fish 3+ or older) indicates strong recruitment, relatively low angler harvest, and a higher proportion of larger fish when growth is good. Low age structure (<10% of adult fish 3+ or older) combined with good growth indicates relatively high angler harvest, high natural mortality, and/or missing year-classes. Inconsistent recruitment and single year-classes moving through the
population most likely cause variability in age structure within a lake.

Information Provided by Arkansas Game and Fish Commission

4.5 - Size Structure

Size structure, the percent of fish greater than 250-mm (10”) excluding YOY, indicates the percentage of desirable fish available to the angler. Size structure is 14 dependent upon recruitment, growth rate, and mortality. It is related to age structure since older fish are larger whenever there is sufficient forage.

Size structure is considered optimal if 30-59% of crappiei are greater than 250mm (10”). Fewer points are awarded to higher values of size structure because a high percentage of large crappie also indicates lowered numbers of younger fish and possible missing year-classes. Missing year-classes can cause negative effects to the size structure for several years.

High scores for size structure are assigned to a wider range of percentages when density is high. In a dense population, high percentages of large fish are less likely to indicate missing year-classes.

Size structure assessment is useful in predicting the effectiveness of a length limit. For example, a 10” minimum length limit would be less effective when the size structure is either very low or very high relative to the age structure. A truncated size structure dominated by numerous small fish, relative to age structure, indicates a lack of forage and possible stunting. A size structure dominated with a few, large crappies may indicate a missing year class.

Information Provided by Arkansas Game and Fish Commission

4.6 - Recruitement

Recruitment, the number of (YOY) crappiei per net-night, is variable between lakes and may not accurately describe abundance. Within the same lake, however, recruitment should be consistent from year to year.

Catch rates of 4 to 29 crappie YOY per net-night is considered optimal. Recruitment values provide insight into year-class strength. When growth is good, high values are given to a wider range of percentages because density is less likely to be the limiting factor. Low recruitment (very near 0) probably indicates low densities of YOY and potential missing year-classes, while high values are often associated with lakes that display higher crappie densities and slower growth. Boxrucker (1989) suggested that excessive recruitment may adversely affect growth, but is sometimes unclear and usually restricted to the first and second year of growth. Low recruitment or missing year-classes also reduces the numbers of fish available to fishermen and the numbers of spawning adults.

Recruitment directly affects density, size structure and age structure. Because trap nets may not sample Age-0 in proportion to their true abundance, the contribution of this metric to the assessment value is reduced. Age structure may be a more accurate indicator of recruitment, although, it takes 1 to 2 years for a year class to show an effect.

In summary, an optimal crappie population in Arkansas will exhibit a growth rate of 201-mm to 275-mm at Age-2+, have a size structure (percent > 250-mm) above 30%, and show consistent recruitment. These metrics are minimally sufficient to describe a good crappie population. Age structure, growth, and mortality estimates are needed to determine the suitability for enacting minimum length limits and/or other harvest regulations.

Of the 12 lakes that we have more than 1 year’s data, 4 lakes (Overcup, Harris Brake, DeGray, Lake Charles) exhibited metrics described for a good population. Bear
Creek Lake has a high size structure assessment value, but a high growth rate may indicate less than optimal density. Horseshoe and Felsenthal both display low growth rates and possible stunting. Lakes Beaver, Bob Kidd, Nimrod, and Horseshoe all show large variations in age structure probably due to inconsistent recruitment and missing year classes.

Information Provided by Arkansas Game and Fish Commission

5 - Management Actions

Predator/Prey Manipulation

The need to improve crappiei growth rates in reservoirs has been the focus of many management efforts. The strategies used typically involve manipulation of the predator/prey balance. This is especially challenging when dealing with species such as crappie which are both planktivorous and piscivorous (after reaching approximately six inches in length) for significant portions of their lives. A management strategy that favorably affects the planktivorous life stage may have no effect or possibly a negative effect on the piscivorous life stage.
The introduction of threadfin shad as supplemental forage for a crappie population has been met with mixed results. Supplemental stocking of threadfin shad may adversely impact young crappie in a population. Competition for plankton between threadfin shad and young crappie can occur if shad densities are too high. Kansas Game and Fish Commission cut their stocking rate of threadfin shad from 25 per hectare
to 12.5 per hectare because of possible problems with competition for zooplankton on Osage Lake (Mosher 1984).
Overwinter survival and availability of threadfin shad broodstock are viable concerns for the fisheries manager. Sustained winter water temperatures below 41 degrees
Fahrenheit are lethal to threadfin shad and will occur in Arkansas lakes during some winters.
Threadfin shad have also been shown to be valuable prey for crappie (McConnel and Gerdes 1964; Bartholomew 1966; May et al. 1975; Hepworth and Pettengill 1979).
Some studies have documented growth of larger piscivorous crappie following supplemental stocking of threadfin shad. These growth gains were most notable in systems where forage was deficient before threadfin shad introductions. Because many Arkansas lakes and reservoirs already contain adequate shad forage, shad introductions may not be beneficial.
Boxrucker (1987) reported the population of crappie in Thunderbird Reservoiri, Oklahoma improved after the introduction of saugeye. It appeared the improvement of
crappie population structure was the result of a density dependent growth response resulting from predation on crappie by adult saugeye. Horton and Gilliland (1990) found
that saugeye in Thunderbird Reservoir began feeding on crappie after reaching 350-mm (14 inches) and that crappie comprised more than 60% of the diet of saugeye greater
than 525-mm (21 inches). Saugeye became significant predators of crappie after reaching 457-mm (18 inches). This information, along with concerns regarding overharvest of “needed predators” led to the implementation of an 18-inch minimum limit for Thunderbird Reservoir saugeye.
Fisheries managers should consider interactions of adult saugeye and existing predator populations. In systems with high shad densities, crappie may not be readily utilized as forage by the saugeye. If data from Arkansas lakes indicates bass populations are not effective predators due to high turbidity or thick vegetation, saugeye might also be poor at controlling crappie density.
Supplemental crappie stocking has long been used as a management strategy
when overexploitation, increased fishing pressure, or poor recruitment has led to a
decline in the crappie population. Currently, the Arkansas Game and Fish Commission
stocks approximately 0.5 million black and white crappie combined in many of its lakes
and reservoirs annually to improve crappie fisheries. However, Murphy and Kelso
(1986) suggest that several factors, including post-stocking survival, determine the
success of any stocking program.
Post-stocking survival of hatchery-reared fish is related to many variables including
fish size and condition, pre- and post-stocking environments, genetics, and handling and
transportation processes (Mazeaud et al. 1977; Parker 1986; Williamson and
Carmichael 1986; Wallin and Van Den Avyle 1995). Estimates of initial post-stocking
mortality rates of crappie reported from only a few studies in the literature ranged from 0-
Sammons et al. (2000) assessed initial post-stocking mortality, year-class
contribution, and predation upon recently stocked crappies in seven Tennessee
impoundments. Their initial post-stocking mortality rates for crappie ranged from 0-95%,
averaged 16%, and were most heavily influenced by extreme hauling densities (144g/L).
Exposure to stresses such as poor water quality and overcrowding during removal from
hatchery ponds likely influence initial crappie survival and should be considered to
improve the stocking process. 19
Year class contribution is commonly used to evaluate the effectiveness of a stocking
program (Boxrucker 1986; Heidinger and Brooks 1998; Sammons et al. 2000). Year
class contribution and survival of stocked fish has been shown to vary from lake to lake
and from year to year within the same waters (Fielder 1992; Elrod et al. 1993; Heidinger
and Brooks 1998; Sammons et al. 2000). Crappie year class contribution from
supplemental stocking ranged from 0-93% in seven Tennessee impoundments, and
indicates that supplemental crappie stocking is not successful in all Tennessee
reservoirs (Sammons et al. 2000). Angleri creel data also indicated that in one
Tennessee reservoir only 1% of stocked crappies since 1995 had contributed to the
fishery through 1998, while in another reservoir stocked crappies contributed
significantly to angler’s creel during the same time. Predation by resident piscivores on
stocked crappie was a primary factor suspected of limiting stocking success in some
Tennessee impoundments.
Predation on stocked fishes by resident predator fishes has been commonly
theorized (Fielder 1992; Elrod et al. 1993). The occurrence of stocked crappies in
predator stomachs containing food ranged from 14 - 41% in five Tennessee reservoirs
(Sammons et al. 2000). Size of stocked crappie may have increased predation risk,
because stocked black crappie were on average 30% and 40% smaller than black and
white crappies found in the wild at the time of stocking. Sammons et al. (2000)
suggested that high predator densities in some Tennessee impoundments are a
significant factor limiting supplemental crappie stocking success.
Success of stocking contributions have been shown to vary with fluctuations in
natural year-class strength, in which highest contributions from stocked fish developed in
years when natural recruitment was low (Heidinger and Brooks 1998). In Normandy
Reservoir, Tennessee where supplemental crappie stocking was shown to be
successful, natural recruitment was considered below average (Sammons et al. 2000).
Hence, when strong year-classes are present in the fishery, stocking contributions are
less likely to be effective.
The effectiveness of stocking crappie to supplement missing year classes or poor
recruitment is currently being evaluated in Arkansas (S. Lochmann, University of
Arkansas at Pine Bluff, unpublished data). Early results suggest that there should be
some clear guidelines for stocking crappie in Arkansas’ waters.
1. Crappie should be stocked according to the most successful or dominant crappie
species in the lake. If the lake is dominated by a particular species, then the 20
environmental conditions of the lake are apparently more favorable or conducive for
that species recruitment and survival.
2. Crappie handling and hauling mortality needs to be minimized to 10-20%.
Handling/hauling mortality estimates in the Lake Chicot Crappie Study ranged from
1-40%, while the Tennessee study ranged from 0-95% with an average of 16%.
Unless handling/hauling mortality is minimized, time, money, and manpower are
being misappropriated by supplemental stocking crappie in Arkansas waters.
3. Crappie should not be stocked in lakes where Age-0 to Age-1 mortality is high. If
the annual mortality rate of Age-0 crappie in the natural population is high, then it is
likely that stocked crappie will have a similar high mortality rate due to poor
conditions such as lack of adequate forage, habitat, or high predation. Fishery
managers can determine mortality rates of Age-0 to Age-1 from cove rotenone
samples conducted over time.
4. Crappie should not be stocked in lakes during years of high natural recruitment,
because supplemental stocking is not likely to make a significant contribution to the
year class. For example, if a lake has a natural reproduction of 500 fish/ha, then
stocking 50 fish/ha (10%) would not make a reasonable contribution to the year
class. This practice would allow for crappie supplemental stockings to be
reallocated to lakes where natural reproduction was unsuccessful.
There is good evidence that supplemental stocking of crappie during years of
unsuccessful reproduction and suitable conditions, such as low initial post-stocking
mortality and decreased predator densities, can make up a reasonable high proportion
of missing year-classes (Sammons et al. 2000). Currently, the Arkansas Game and Fish
Commission stocks approximately 0.5 million black and white crappie combined in many
of its lakes and reservoirs annually to improve crappie fisheries. The decision to
supplementally stock a lake will be based on a combination of technical analysis of
sampling data and social considerations. Lakes with high natural mortality or high
occurrence of Age 0 crappie will be considered poor candidates for supplemental
stocking. New lakes and lakes exhibiting poor natural spawns are considered the best
candidates for stocking. Crappie should be stocked in the fall/winter during the year in
which natural recruitment was poor in an effort to make a significant contribution to the
missing year class. 21
Prioritization of lakes is warranted due to requests for crappie being greater than the
number produced by the hatchery system. Therefore, new and renovated lakes have
the highest priority for crappie stockings and should be stocked at a rate at or near
250/ha (100/acre). Supplemental stocking justification varies on technical and social
needs as well as hatchery capabilities. Stocking rates are provided as guidance only to
be considered in the matrix of population needs, social needs, and hatchery capabilities.
Lakes under 1,215 ha (3,000 acres) will be given next priority and will be stocked at a
rate of up to 125/ha (50/acre). Finally, lakes ranging in size from 1,215 to 4,050 ha
(10,000 acres) will be stocked at a rate of up to 62/ha (25/acre). Lakes over 4,050 ha,
including Corp of Engineer impoundments, should only be stocked through the nursery
pond system to optimize hatchery production space.
Nursery ponds will be utilized for supplemental crappie stocking when located on
reservoirs, including Corps of Engineer impoundments, where stocking is requested.
This will free up hatchery pond space for other species due to the length of crappie
production (March-October) and also decrease handling/hauling mortality. However,
crappie may not be needed every year if lakes are capable of producing adequate
natural spawns, therefore, District Fisheries personnel may choose to reallocate pond
space to other species, which could benefit from the nursery pond. District Fisheries
personnel are strongly encouraged to use other means such as lake fertilization, water
level manipulation (controlled winter drawdowns), and habitat improvement to enhance
crappie recruitment. Crappie brood stock collection for the nursery ponds will also be
the responsibility of District Fisheries personnel.

Lake fertilization is a widely accepted technique used to improve fish populations.
The fertility or richness of the water determines the productivity of the lake, and a more
productive lake will support more fish. Fertilizer increases lake productivity by
stimulating the growth of microscopic plants known as phytoplankton. Phytoplankton is
the basis of the food chain and is a primary food source for many larval fishes.
Increases in phytoplankton will increase the production of zooplankton, which ultimately
increases fish production. This is especially important to crappie, which are primarily
planktivorous feeders until they reach a length of 150-mm (6-inches) and then switch to
a more piscivorous diet. Upper and Lower White Oak Lake has been fertilized since 22
1978 and 1988 respectively, and has resulted in a 4-5 fold increase in the number of
crappie YOY/hectare produced since the fertilization program began (D. Turman, AGFC,
unpublished data).
Controlled winter drawdowns administered every four to five years is an effective,
low cost management tool that provides several positive benefits to a crappie population.
Nutrients tied up in exposed substrate are oxidized and released back into the system
when the lake is refilled, resulting in a natural lake fertilization. Reduced lake area
concentrates fish and allows for heavy crappie predation on forage species and
increases in angler success and harvest. Winter drawdowns are also useful in
controlling, by freezing, undesirable or expanding aquatic vegetation. For greatest
effectiveness, drawdowns should be conducted from August through January and
expose from 40-50% of the lakebed, which can usually be achieved with a 4-6 foot
Fishery biologists have long suspected that reservoir hydrology influences crappie
reproductive success and contributes to the cyclic nature of these fisheries. Successful
reproduction and recruitment of fishes has been linked to years when high water levels
provided more spawning sites and protective cover for larval fish (Bennett 1954, 1970;
Bross 1969). Side channels and backwater areas have been shown to provide prime
habitat for a variety of fish species (Bade 1980; Pitlo 1992).
Drawdowns or dewatering of backwater areas during spawning can result in marked
reductions in habitat size and quality, including temporary loss of the littoral zone and its
associated vegetation. The temporary elimination of the littoral zone can also result in
the loss of juvenile fish, because they use littoral zone aquatic vegetation as shelter from
adult piscivores (Werner et al. 1983). Dewatering can also reduce availability of
spawning substrate, and expose nests with eggs and larval fish to drying conditions.
Ploskey (1986) found that spawning success for most littoral species was positively
related to water level increases during the spawning period because additional spawning
habitat was produced for adults, and increased food and habitat resources were
available for larval fish.
It is widely recognized that management strategies designed to improve crappie
populations and harvest is dependent primarily upon water-level management.
Therefore, the Arkansas Game and Fish Commission will actively pursue opportunities 23
to positively influence water control policy and operations on Federal water project lakes
to benefit crappie fisheries.
Lake managers have long recognized the advantages of structure to attract and
hold fish. The primary purpose of fish shelters or attractors is to congregate fish to
improve fishing success for anglers. Fish can also be encouraged to spawn when
provided with good spawning substrate.
Suitable shelters can be constructed from a variety of materials. Brush, tires, stake
beds, rock piles, standing timber, and shoreline vegetation all make good fish attractors.
Establishing native aquatic vegetation in the littoral zone is particularly useful for
impoundments that lack fish cover, and is currently being studied on Greeson and Bull
Shoals lakes in Arkansas (C. Horton, AGFC, personal communication).
The placing of fish attractors in large impoundments has been shown to improve
catch rates and harvest of fish. The Bull Shoals/Norfork Fish Coveri Project installed 600
fish attractors containing over 70,000 trees (M. Oliver, AGFC, personal communication).
The attractors covered 65ha (160ac) of lake bottom and extended 53 km (33mi) of
shoreline. Scuba inspection and angler reports indicated that the attractors were
successful in congregating fish and improved fishing and spearfishing over control
areas. Short-term evaluation of fish attractors in seven Florida lakes indicated that areas
with attractors produced significantly higher angler catches than control areas. Both
number and weight of fish increased after the addition of artificial structures in Wewoka
Lake, Oklahoma (Wright 1979).
Brush shelters have been shown to be more effective than most other materials
used to construct attractors. Reef construction from tires, brush, and cement blocks in
Lake Tohoekaliga, Florida revealed that more fish were observed and caught around
brush than other materials, but all types of attractors congregated more fish than open
water control areas.
More recently several artificial shelter designs have come on the market that are
made from plastic or synthetic materials. Fish attractors made from PVC tubing were
experimented with in Lake Chicot in 1985, and more recently heavy duty snow fencing
was used to attract and hold fish. Both materials were successful in congregating fish
and resulted in increased angler success (J. Smith, AGFC, unpublished data).
Habitat assessments are to be performed on Commission-owned and Federal water
project lakes to determine crappie habitat needs. Habitat assessment protocols are to 24
be developed and feasibility plans are to be drafted and implemented to address the
needs as budget and resources allow. Fisheries Division will actively pursue
opportunities to implement appropriate crappie habitat improvement projects with the
general goal of improving habitat statewide.

Information Provided by Arkansas Game and Fish Commission

5.1 - Harvest Regulation Guidelines

Harvest regulations and management strategies are recommended to shift crappiei populations toward what is considered a good population, as previously described
(Figure 1). This chart outlines a consistent and objective way of assessing crappie
populations, which will help fish managers identify problem areas and direct them
towards needed research and management activities. Harvest regulations assume
angling exploitation is significantly impacting the size and age structure of a crappie
population. Crappie 10-inches and larger provide considerably more benefit to anglers
than do smaller crappie. Ten inches was considered to be the minimum size that should
be harvested by anglers based on length-weight relationships showing that white and
black crappie begin adding proportionally more weight per unit length when they are 8 or
9-inches long. According to Mark Zurbrick, (Missouri Department of Conservation pers.
comm.), fifteen 10-inch crappie will weigh more than twenty 9-inch crappie. Durocher
(1990) found that 8-inch crappie would double in weight if allowed to reach 10-inches.
Restrictive size limits can perform an important role in managing crappie
populations. The success of restrictive size limits meeting certain management
objectives for crappie populations has varied among water bodies (Colvin 1991; Larson
et al. 1991; Webb and Ott 1991; Mitzner 1995; Boxrucker 1999). Length limits are 16
probably the most effective tool for controlling crappie harvest, because creel limits
which are likely to be acceptable to anglers (>15 fish/day) do not significantly affect
crappie population characteristics (Allen and Miranda 1997). Length limits can also
increase average weight of fish harvested by anglers without a considerable decrease in
yield. Allen and Miranda (1995) evaluated published data from crappie populations
across the southeastern and Midwestern U.S., and indicated that only under conditions
of rapid growth and low natural mortality would minimum length limits improve yield in
crappie populations. In addition, crappie populations with slow growth or high natural
mortality are probably best managed without a length limit.
Crappie populations are dynamic and greatly influenced by annual recruitment.
Evaluation of a crappie length limit may be misinterpreted when population or creel
survey data is used, since they are influenced by highly variable recruitment. Colvin
(1991) reported that poor recruitment prevented an accurate assessment of a crappie
length limit in a Missouri reservoir. Webb and Ott (1991) discovered that a 10-inch
minimum length limit improved crappie fisheries in three reservoirs, however, post-
evaluation after the limit was established indicated that it was short-lived (3-4 years).
The use of population modeling programs such as MOCPOP or FAST can assume
constant or variable recruitment and predict long-term effects on harvest prior to the
implementation of minimum length limits. The results of modeling can then be evaluated
by subsequent collections of field data. Maceina et al. (1998) effectively used a
Beverton-Holt equilibrium yield model to predict the effects of four different crappie
length limits in Weiss Lake, Alabama. They found that a 10-inch minimum length limit
would increase yield of crappie, only if conditional natural mortality rates were less than
35%. However, anglers would also have to accept a decrease in their creel limit in
exchange for the increased average weight of crappie.
Recruitment from fry into the adult population and subsequent growth appears
partially dependent on predators, primarily largemouth bass. High predator densities
may reduce crappie recruitment due to intense predation, in which surviving crappie are
fast growing and reach large size.
In lakes with dense, slow growing crappie, relaxed creel limits could be beneficial. If
aquatic vegetation or turbidity is causing inefficient predation, these conditions should
also be controlled.

Finally, anglers on a particular water body may desire higher numbers of smaller
fish, and knowledge of angler preference when minimum length limits are being 17
investigated should be an important consideration for the fishery manager in the
decision-making process. Due to the various growth and natural mortality rates of
crappie populations across the state, statewide length limits may be detrimental and
result in substantial reductions in yield to some fisheries. Therefore, statewide length
limits are not a recommended management strategy for Arkansas crappie populations.

Information Provided by Arkansas Game and Fish Commission

6 - Research / Resource Needs


  1. No management plan is complete without proper evaluation. Management strategies suggested in this plan should be appropriately evaluated after exploitation studies have been initiated, population modeling has been conducted, harvest restrictions have been imposed, or creel surveys have been completed. Evaluation of additional trap netting data using the Crappie Stock Assessment will yield further information regarding the effectiveness of the management plan.
  2. Natural mortality rates of Age-0 to Age-1 crappiei should be derived by fishery managers to assess where supplemental stockings will be most beneficial.
  3. Handling and hauling mortality of crappie should be estimated and reduced by hatcheries to minimize post-stocking mortality to 0-20%.
  4. Crappie marking techniques, such as six-hour oxytetracycline baths, should be investigated for supplemental stock identification purposes. Once a desirable marking technique is accepted, future contributions of stocked fish to year-classes can be evaluated.
  5. Fishery managers should re-evaluate current crappie minimum length limits using population modeling programs.
  6. A Crappie Recruitment Model is needed to determine what variables are having the greatest impact on crappie recruitment in Arkansas waters. The model would potentially help fishery managers identify those problems in reservoirs where corrective management could be applied, and would also help in predicting missing year-classes and thus, supplemental stocking guidelines on an annual basis.
  7. Fishery managers should explore the use of other sampling techniques such as the larger 8’ x 8’ or 6’ x 6’ floating trap nets and spring/fall electrofishing in lakes where standard trap net gear has been ineffective at sampling the crappie population.


  1. Trap net boats and motors ($6,000) replaced as needed
  2. Trap nets ($475/net) replaced as needed
  3. Dissecting Microscopes
  4. Ocular micrometers
  5. Data reduction and analysis software for trap nets (currently being developed).
  6. Exploitation/Tag Reward studies ($2,500/each)
  7. Continuing Education workshops on population modeling
  8. Develop standardized protocol for assessing habitat needs in Arkansas lakes.

Information Provided by Arkansas Game and Fish Commission

Crappie Sight and Jig Selection

Image of Crappie Jig AssortmentCrappie can see colors very well and that is why most anglers like to use colorful lures to fish for them. However, like all fish, a crappie’s ability to see is influenced by water depth, light levels, water clarity and water temperature. Also, a crappie's willingness to attack lures of different colors and presentations depends heavily on the fish's activity level.

Water filters colors out of light and certain colors disappear first. Just think of a rainbow that has red hues on one side and gradually fades to blue colors on the other side. The colors on the red side are filtered out first and the colors on the blue side are filtered out last. Consequently, as water begins to get deep it looks green, but deeper water looks blue. Because of this natural law, red lures are visible only in shallow water, orange a little deeper, yellow even deeper, green deeper still and blue lures are visible in the deepest water. Black is also a good deep-water lure color. White is visible at many depths, because it reflects any available light. But there are other vision factors that you must consider before you select a lure.

The effects of water clarity and light levels are not always obvious. The simplest way to remember this concept is that richer versions of any color are most visible in clear water and bright light, while lighter, pastel versions of each color are most visible in stained or murky water and/or low light levels. In other words, red, orange, white, rich green and deeper blue are most visible in clear water with bright light. As light levels fade and/or the water becomes murkier, the best colors become pink, yellow, chartreuse, lighter blue, and black. When the fish seem to lose interest in a lure that was working well earlier in the day, it may be due to changes in light or water clarity. If changes in wind or current have let the water calm down and become clearer, or if clouds have cleared away to allow brighter light, change to richer lure colors or white. If the wind has churned up the water and decreased visibility or if clouds have moved in or the sun is going down, switch to pastel colors or black.

Image of Berkley Vanish Fluorocarbon LineIn some recent studies, water temperature was determined to have a dramatic effect on fish vision. Since crappie rely heavily on vision for hunting, this information is important for crappie anglers to understand. The concept is very simple: the colder the water, the better a fish can see. This is because the lower temperatures help the cells in a fish's eye to function better. This means that crappie, like other fish, may be able to see smaller lures at deeper levels in cold water than they can in warm water. It also means that they will be better able to see fishing line, so an angler may need to use lighter monofilament or fluorocarbon line in cold water.

Finally, a crappie's activity level will determine how it reacts to lures of different colors and presentations. The most substantial difference in lure color is the contrast between lure and background color. Active fish are more likely to attack lures that contrast with the color of the water and structure in the area. Think of red, orange, yellow, white, and sometimes black if the background is light. Inactive fish are more likely to attack lures that blend with the surrounding background colors, like a baitfish would. Try green, chartreuse, blue, neutral colors, and occasionally black if the background is dark. For lure presentation, active fish are more likely to attack a lure with more movement, while inactive fish are more likely to attack lures with less movement. There needs to be some lure movement, though, even if it is followed by a pause, because movement is what tells the fish that the lure may be food, rather than part of the background. Always consider water depth, water clarity, light levels, and water temperatures to help decide which colors to try first. And always be ready to try something different if the first choice doesn't work.

Crappie Species (Simple Description)

Black Crappie

Picture of a Black Crappie. Flati and silvery in appearance and marked with irregular dark spots, the crappie is a very attractive and desirable fish. The black crappie has 7 or 8 eight spines in the dorsal fin. It prefers clear water conditions.

White Crappie

Picture of a White Crappie. Looks similar to the black crappie but only has 5 or 6 spines in the dorsal fin. The dark spots on its sides are consolidated into vertical bars. The white crappie is more tolerant of turbid water than the black crappie and well suited to reservoirs such as Lake Tschida and Patterson Lake.

Courtesy of USGS -

Crappie by Degrees

Temperature Template For Year-Round Actioni! 
By: Don Wirth

Of all the factors determining crappiei location and activity, none is more critical than water temperature. With that in mind, I assembled a panel of veteran crappie guides including Jim Duckworth, Steve McCadams, Fred McClintock, Larry McMullin, Tom Moody and Harold Morgan, and picked their brains about how crappie locations and fishing patterns vary with changing water temperatures. These experts pitched in to help me create this simple but useful cheat sheet that spells out where crappies will be and what you need to do to catch them in 5-degree water temperature increments year-round.

Water Temperature: 35 Degrees 
Overview: Crappies will be deep and sluggish now, but they’re still catchable with the right presentation.
Key Location: Check main-lake river channels for crappies holding tight to bottom cover in 30 to 60 feet of water.
Primary Patterni: Vertical presentations rule in the dead of winter. Fish straight down, using live minnows on a Kentucky rig (see diagram below) or spoons jigged just above the fish.

Water Temperature: 40 Degrees
Overview: Crappies will begin migrating from deep river channels toward major tributaries, where they will eventually spawn. They’ll often suspend in open water now rather than relate to cover or breaklines.
Key Location: Waves of crappies will stage off points leading into reservoir tributary arms, suspending off these structures 20 to 30 feet deep. Some fish will remain on river channel structure in considerably deeper water.
Primary Pattern: Wind-drift 1⁄8- to 1⁄4-ounce jigs on longlines around tributary points. Watch your graph for suspended baitfish schools—crappies are seldom far from a food source.

Water Temperature: 45 Degrees
Overview: Many crappies have started migrating toward their eventual spawning areas. It’s prime time.
Key Location: Target crappies hanging tight to submerged wood on deep channel banks near the entrance to tributaries, 12 to 25 feet deep. Most fish will range from the primary point to about a quarter of the way back into the creek arm.
Primary Pattern: Target-cast grubs to channel bends with wood. Cast, let the grub sink until it contacts the cover, then immediately begin swimming it slowly and steadily back to the boat.

Water Temperature: 50 Degrees
Overview: The prespawn migration is in full swing now, with large numbers of crappies moving into reservoir tributary arms. Stragglers suspending in deep water off tributary points will make their move shallower following a few days of mild, sunny weather.
Key Location: Continue targeting the creek channel migration route, keying on isolated wood cover along channel bends for the largest concentration of fish. Crappies instinctively remain 12 to 20 feet deep now, probably to insulate themselves from the impact of frontal passages.
Primary Pattern: Map out the creek channel with marker buoys, then bump a Kentucky rig baited with minnows or a minnow/tube bait combination along the channel drop.

Water Temperature: 55 Degrees
Overview: Expect the bite to get more aggressive as crappies begin feeling “the urge to merge” and feed heavily before spawning.
Key Location: A few big fish will be in the upper half of tributary arms, but you’ll find numbers of fish in the lower half, still relating to the creek channel migration route. Shallow ditches veering off the creek channel and running toward shallow spawning coves can hold huge fish.
Primary Pattern: Target ditches with grubs and small crank baits; on mild days, crappies may be as shallow as one to three feet deep along these structures. Work the creek channel with grubs, keying on brushy cover in the six- to 12-foot zone.

Water Temperature: 60 Degrees
Overview: Crappies spawn in water from around 65 to 75 degrees, so the immediate prespawn period is a good time to load the boat with oversize fish. Baitfishi schools continue to be a primary location factor now as crappies fatten up before spawning.
Key Location: Hopefully you did your homework while the lake was drawn down during winter and marked the location of brushy cover and stake beds on your map and GPS. Now that the water is higher, crappies will be all over this cover midway into tributary arms, three to eight feet deep
Primary Pattern: Tightlining minnows and jigging tube baits around sunken cover will score heavy crappie catches in murky water. In clear water, back off your target, make a long cast and swim a curlytail grub.

Water Temperature: 65 Degrees
Overview: Crappies will be shallow now; some will be spawning, but many will still be in a prespawn mode. Don’t rush the season—if you aren’t catching quality fish on likely spawning cover, back off and target prespawn crappies instead.
Key Location: Crappies will be in the upper half of tributary arms, holding tight to isolated stake beds and submerged brush piles. Prespawn fish will be in three to six feet of water, but will chase minnows shallower.
Primary Pattern: Tight-lining minnows on long rods is the standard method now, but target-casting grubs and tubes to submerged wood works, too.

Water Temperature: 70 Degrees
Overview: Spawning season kicks in big-time! Male crappies fan out the nest while females hang back waiting for the water temperature to rise a degree or two before moving onto the beds.
Key Location: Spawning takes place on woody cover (stake beds, brush piles, etc.) in the upper ends of brushy coves and creek arms, anywhere from three to 12 feet deep depending on the lake’s clarity.
Primary Pattern: Cast tubes and grubs or tight-line minnows close to cover. If you’re catching numbers of small males, back off and hit deeper isolated stake beds and stumps for the bigger females.

Water Temperature: 75 Degrees
Overview: Some crappies will be done spawning while others are finally moving onto their beds. Postspawn fish will hang around bedding areas for several days until the water temperature rises.
Key Location: Spawners will be on wood from three to 12 feet deep depending on water clarity. Postspawn fish will be on isolated pieces of cover adjacent to spawning sites. 
Primary Pattern: Determine the crappies’ spawning mode. If tube baits or minnows don’t produce strikes in thick brush and stake beds, target-cast grubs to scattered wood.


Water Temperature: 80 Degrees
Overview: Most crappie fishermen hang up their rods after the spawn, but a shift in tactics can yield fast action on postspawn fish.
Key Location: Before moving to their deep summer haunts, many crappies gravitate to the edges of flats, hanging tight to scattered wood or suspending above the breakline closest to the structure.
Primary Pattern: Troll small diving crankbaits like the 200 series Bandit around the edges of flats in the six- to 18-foot zone, occasionally banging the plugs off stumps and bottom.

Water Temperature: 85 Degrees
Overview: Crappies will be moving out of tributaries via the same creek channel migration routes they traveled before spawning.
Key Location: Slabs gang up on secondary and primary points that drop quickly into deep water. Look for them suspending 18 to 30 feet deep around baitfish schools.
Primary Pattern: Target channel points using a Kentucky rig bumped slowly along bottom.

Water Temperature: 90 Degrees
Overview: In the Sun Belt, water temps in the 90s are common by August. Crappies suspend for long periods now to conserve metabolic energy. River-run reservoirs with a flowing channel usually have better fishing now than slackwater lakes.
Key Location: Channel ledges lined with standing timber or brushy cover offer your best bet now. Crappies are probably suspending 18 to 30 feet deep in 60 feet of water.
Primary Pattern: If fish are suspended high in the water column, slow-drifting minnows or tubes through the school can produce strikes. If they’re tight to bottom, use a Kentucky rig.

Water Temperature: 85 Degrees
Overview: While the lake’s surface temperature cools quickly as the days grow shorter in early fall, deeper water cools more gradually, so expect to find crappies deep.
Key Location: Deep channel cover continues to be your best bet for finding concentrations of fish.
Primary Pattern: Kentucky rigs bumped along cover and spoons jigged over wood.

Water Temperature: 80 Degrees
Overview: Crappies are following channels, or moving shallow to prey on baitfish schools, so expect a pickup in activity.
Key Location: Primary tributary points, where the creek and river channel intersect, can hold a ton of baitfish and crappies now.
Primary Pattern: Target the 15- to 25-foot zone with a Kentucky rig. If crappies are suspended, slow-troll cranks.

Water Temperature: 75 Degrees
Overview: Shadi move into shallow coves and tributaries to spawn, and crappies follow.
Key Location: The first half of reservoir tributary arms will hold large schools of crappies.
Primary Pattern: Target scattered wood along the creek channel 10 to 20 feet deep with grubs and Kentucky rigs.

Water Temperature: 70 Degrees
Overview: As baitfish move farther back into the tributaries, crappies follow, feeding on wandering schools.
Key Location: Check channels, secondary points and flats in the back half of reservoir tributary arms. Crappies hold anywhere from two to 10 feet deep, depending on water clarity.
Primary Pattern: Use a bass fishing approach. Coveri water quickly, casting a grub or small crankbait to every piece of wood you encounter.

Water Temperature: 65 Degrees
Overview: Reservoiri drawdown usually starts about now; dropping water levels push baitfish and crappies out of tributary arms toward the main body of the lake.
Key Location: Crappies use the same migratory routes they took in spring to move back to the main lake. Find them on creek channel cover in the 12-foot zone.
Primary Pattern: Cast grubs or bump Kentucky rigs around creek channel cover.

Water Temperature: 60 Degrees
Overview: Colder nights spell a rapid cool-down. As drawdown continues, many crappies leave reservoir tributaries.
Key Location: Deep points and steep bluff banks at or near the mouths of tributaries hold large schools of crappies in the 15- to 25-foot zone.
Primary Pattern: Drifting live minnows on long rods rigged with heavy sinkers is a proven fall tournament tactic. Lower the sinker to bottom, then reel up to the level of suspended crappies.

Water Temperature: 55 Degrees
Overview: The 60-degree pattern should remain about the same until the lake turns over—assuming it does.
Key Location: Deep points and steep rock bluffs near tributary mouths hold concentrations of fish.
Primary Pattern: If crappies aren’t on the points, drift jigs or troll crankbaits for fish schooled in the open water between the points.

Water Temperature: 50 Degrees
Overview: Turnover usually occurs during the fall-winter transition, triggering a wholesale movement of crappies.
Key Location: Intersection of channels, 25 to 40 feet deep.
Primary Pattern: Crappies are often tight to bottom right now, and they’re going to stay that way through the cold weather months, so bang a Kentucky rig along the channel.

Water Temperature: 45 Degrees
Overview: Crappies have settled into a winter pattern now, setting up on deep channel structure.
Key Location: Channels with brush, 18 to 40 feet deep.
Primary Pattern: Fish the bottom along bends and pronounced drop-offs.

Water Temperature: 40 Degrees
Overview: In hyper-chilled water, crappies are deep and feed only sporadically.
Key Location: Channels with brushy cover or submerged standing timber. Look for crappies 40 to 60 feet deep.
Primary Pattern: Fishing spoons along the channel, or hug bottom with your Kentucky rig.

Water Temperature: 35 Degrees
Overview: Crappies are sluggish, requiring a patient approach.
Key Location: Slabs are on bottom 40 to 60 feet deep along main-lake channels.
Primary Pattern: More bottom rigging—look for the cycle to start anew soon after water temps bottom out.

Fish Movement

PSR 96-04  October 1996

Fish Movement on the Upper Mississippi River

by Joseph H. Wlosinski and Scott R. Marecek

The Environmental Management Technical Center is nearing completion of a two-year project to evaluate the effects of locks and dams on fish passage. As part of this project, we collected all available data from previous fish telemetry and mark/ recapture studies of the Upper Mississippi River (UMR). Other data were obtained from the Wisconsin Department of Natural Resources, Minnesota Department of Natural Resources, Commonwealth Edison, Iowa Department of Natural Resources, Illinois Department of Conservation, Illinois Natural History Survey, U.S. Army Corps of Engineers, Upper Mississippi River Science Center, Normandeau Associates Inc., and Clark Thomas Moen.

We found 126 studies that examined fish movement on the UMR. We were able to obtain at least some of the original data from 84 of the studies.

Image of Crappie Movement Data Table

Studies included information for 15 species of fish: black crappiei, white crappie, bluegill, northern pike, common carp, channel catfish, Figure 1freshwater drum, flathead catfish, largemouth bass, paddlefish, sauger, shovelnose sturgeon, smallmouth bass, walleye, and white bass (Table 1).

Less than 10% of the marked fish were recaptured. No black crappie, white crappie, bluegill, northern pike, or common carp were found to have moved across a single lock and dam. Of the 5,253 fish recaptured in the studies we reviewed, 4,594 (87%) remained in the pool where they were initially marked, 420 (8%) moved upriver and 239 (5%) moved downriver (Fig. 1). Some of the fish crossed more than one dam. The majority of the marked and recaptured fish were walleye. Most of the recaptured walleye and sauger that moved across dams did so in an upriver direction, while most channel catfish moved downriver.

Figure 2We also investigated the head differential (HD) between headwaters and tailwaters when fish were at large. Unfortunately, we could not pinpoint the HD for most fish that crossed dams because of the long periods between when they were marked and recaptured. We do know, however, the HD for 68 fish. Of these 68 fish, only five crossed in a downriver direction. Four crossed with a HD of less than a foot. The fifth crossed when the HD was at six feet. Of the fish moving upriver, the majority crossed with a HD of less than one foot (Fig. 2). A HD of around one foot usually signifies that dam gates are out of the water and open river conditions exist.

This study can not supply conclusive proof of the effects of locks and dams on fish passage because the original 84 studies were performed with various experimental designs and most fish were at large for long periods of time. However, the study does support the view that locks and dams do adversely affect fish movement.

This report is a product of the Long Term Resource Monitoring Program for the Upper Mississippi River System.

For further information, contact
Joseph H. Wlosinski
U.S. Geological Survey
Upper Midwest Environmental Sciences Center
575 Lester Avenue
Onalaska, Wisconsin 54650
Phone: 608/783-7550, ext. 56

Project Status Reports (PSRs) are preliminary documents whose purpose is to provide information on scientific activities. Because PSRs are only subject to internal peer review, they may not be cited. Use of trade names does not imply U.S. Government endorsement of commercial products.

All Project Status Reports are accessible through the Upper Midwest Environmental Sciences Center’s website at

Courtesy of USGS -

Identifying and Solving Sonar Interference Problems


In the world of marine sonar and the modern day angler, there is no doubt that as the electrical systems in today's boats get more complicated, the chance that your electronics will experience interference problems increases. Interference shows itself on the display of your depth finder with varying degrees. Minor interference, or noise, can be stray signals that can look like actual targets. Severe noise can completely fill the screen, making simple depth readings impossible. To combat interference, you must first identify which type of noise is giving you trouble. Also, understand that although most noise can be eliminated with fairly simple techniques, some can only be reduced to a more acceptable level.


Interference displayed on a flasher

First off, understand there are five different types of interference problems you may face. They will all look similar on your screen and distract from your ability to get a clear picture of the bottom below, but the remedy for each is quite different.

  1. Acoustical Interference is caused by faulty transducer installation. You will see this noise on the screen only when the boat is traveling across the water, at or beyond the plane speed of the boat. It's caused by an uneven, or turbulent, water flow across the face of the transducer. This applies to transom and in-hull mounted transducer applications.
  2. Sonar Cross-Talk Interference is created by another sonar of similar transmit frequency nearby. It will show itself as lines rotating around the dial of a flasher or diagonal lines across the screen of a graph. When two depth finder's transducer cones intersect, each unit will get confused as to which signals are which.
  3. Ignition Interference comes from engines that introduce ignition noise into the power circuitry. These are power spikes that travel through the power wiring and into your sonar, causing noise to be displayed on the screen or heard in your radio.
  4. Conducted Interference is usually caused by electric trolling motors that incorporate Pulse Width Modulation (PWM) in their speed control. This noise will be evident only when the trolling motor is activated and can vary in intensity through the range of motor speeds. The noise is conducted through the power line and enters your depth finder through the power connection.
  5. Electromagnetic Interference (EMI) is created by the powerful electric trolling motors on the market today. EMI is radiated from the trolling motor's lower unit and power wiring into the air. It is then absorbed into the transducer cable that's attached to the trolling motor. This is a relatively new problem. As trolling motors get more and more powerful, the noise gets worse and worse, overwhelming the cable shielding and noise reduction circuitry that used to protect sonar from this type of interference.

Being able to pinpoint the type of interference you have will be the first step in getting a clearer sonar signal in all waters and conditions. Here are some simple and easy to follow steps to target and then address the problems you may be having.


Acoustical Interference

If your transducer is mounted on the transom or glued in-hull for the purpose of reading depth while the boat is traveling across the water, you may be subject to acoustical interference being displayed on your depth finder. This type of interference makes reading the bottom almost impossible, once you reach a certain boat speed. The screen often is a total clutter of bad signals with a total loss of bottom signal. This noise can be reduced a great deal by adjusting the water flow rate over the transducer surface. This can be done by re-positioning the transducer.


Transom Mounted Transducers

If you do not have enough of downward slop to your transducer, turbulent water will develop under the face of it. Increasing this angle by lowering the back of the transducer will help. Additionally, lowering the whole transducer can help you get down into a more smooth water flow area. However, going down too low can cause the transducer to shoot up water in a "rooster tail". If you have adjusted the angle and not gotten much improvement, then the transducer has been set in a position of what we call “dirty water”, where bubbles are coming off the hull due to a rivet, bad weld or bend in the hull. You'll need to remove the transducer and reposition it in another location on the transom where the water flows more smoothly. Many newer hulls have very steep keel angles, so mounting a transom style transducer so you're shooting at a downward angle can be a challenge. Generally, you want to mount as close to the keel line as possible, but you'll have to balance performance and location. Be sure to follow your transducers mounting instructions carefully.


In-Hull Mounted Transducer

With this mounting application you have limited adjustment options. The key is to make sure you choose a good location and get a good installation in the first place. However if your puck is already stuck to your hull, than it's time for some rework to get things right again. Before you get out the hammer and chisel, see if you can improve the reading by changing the weigh distribution or modifying the trim setting of your boat. Getting the bow to run a little lower may help things considerably. If not, then you'll need to remove the transducer and reattach it in a better location. Usually, dead center, about a foot from the transom, is best. But if there's a strake or a bad spot in the fiberglass there, you'll need to work around that. Testing the location, by setting the transducer in about a half inch of water while you run across the lake, is good way to find the best spot. Doing this is easier said than done and may require ingenuity or a willing helper in some cases.


Sonar Cross-Talk

If your unit has interference with nothing other than another sonar running in your boat, then you have sonar cross-talk interference. For most depth finders, the only real solution is to move the transducers further away from each other. This can help keep the transducer cones from intersecting, but because cones get wider as the depth increases, the problem can not usually be totally solved by position only. Changing one of the sounders to another model that runs on a different frequency than the first will solve the problem. Some modern depth finders, like the Vexilar FL-12 and FL-20, have interference rejection technology that will permit you to simply knockout the interference by pressing a button repeatedly until you see the cross-talk signal disappear on both units. These depth finders can have transducers mounted right next to another unit that runs at the same frequency.


Ferrite core can help eliminate interferenceIgnition Interference

Ignition noise can be a sign of problems with your engine. However, if it seems to be performing well, or you would just rather run her 'til she blows, a Ferrite Core can stop the noise from getting into your depth finder. These are small parts that you pass the depth finder's power wire through, often wrapping it through several times. For Vexilar units, contact Vexilar to get one.


Interference from Electric Trolling Motors

Whenever you use an electric trolling motor on the same boat as a depth finder, you are likely to see noise from the motor on the display of your sonar. Today's high-tech motors perform better than ever, but can be very unforgiving to other electronic devices in the area.


Conducted Interference

A Multi-Meter is a valuable tools for working with electrical systemsIf you disconnect your transducer from your depth finder and you continue to see noise when the trolling motor is running, then you are dealing with conducted interference coming in through the power connection. This can happen when the boat's electrical system does not have one common ground that connects to the water. Using a multi-meter, available at places like Radio Shack, check for proper grounding in your boat's electrical system. Set the meter to measure resistance or continuity. Then connect one lead to the negative battery post that connects to the trolling motor and the other lead to the negative post on your starting battery. The reading should show zero and the meter may beep. Also, check between the negative starting battery post and an unpainted portion of the outboard motor, like the prop shaft or trim tab. You should also measure a complete circuit here as well. If the ground connection is missing between the trolling motor battery and the starting battery, add a small gauge wire, about 18 AWG, with a 1 amp fuse. This will complete the ground connection here. If the ground to the outboard motor is missing you should take your boat into a service shop to see why the ground is missing. All outboards should have this ground. If yours is missing something is wrong. If all grounds are in place, but noise is still a problem, a Ferrite Core can solve the problem.


Electromagnetic Interference

Actual view of EMI signals from an electric trolling motorWhile you’re electric trolling motor is running, disconnect your transducer from the back of your unit. If the interference goes away, then you have EMI created by the rapidly switching voltage and powerful DC motor in the trolling motor's lower unit. Proper grounding and Ferrite Cores can be a good remedy for this type of interference. First, be sure your system is grounded properly as described above. Incorrect grounds are a common source of problems. Vexilar has even incorporated a very unique grounded puck transducer in our sonar systems that will insure the electrical system is grounded to the water at the point of the interference. This helps keep EMI under control, but may not eliminate it completely.

By knowing how to identify interference sources, you will be able to eliminate or greatly reduce the troublesome noise that can render your electronics worthless. It may take a little time and effort in some cases, but it will let you get the most out of your sonar in all conditions. 


Kentucky Lake Crappie Project

Project Overview

(1) We will implant 30 white and 30 black crappiei with radio transmitters. We will track these fish daily throughout the spawn and into the summer to determine their movement patterns in relation to weather and water changes such as clarity, level and flow. This will also reveal what white crappie are doing in relation to black crappie. This will help us understand some of what we already know — that black crappie prefer clearer water with gravely bottoms, spawn in deeper water and spawn slightly earlier than white crappie.

Anglers can help the project succeed by immediately releasing any crappie with a 12-inch long, thin wire hanging out of its belly. Please call the telephone number on the tag if the crappie does not survive. This study is for the sake of all anglers, but we can’t learn anything if the tagged fish get caught. If we get the tag back we can re-implant it into another crappie. But it will be best to just release the crappie if you catch one.

(2) We will implant small plastic yellow tags into 750 white and 750 black crappie to determine angler catch rates. Tags are attached in the back, near the base of the dorsal fin. A reward will be given for the return of each tag. There will be a phone number on the tag to call, or you can use a return envelope available at many of the marinas and bait shops around the lake.

(3) Food preferences of crappie will be looked at throughout the year to determine if there are differences between what the white and black crappie are eating.

(4) We are asking several anglers that fish frequently for crappie throughout the year to keep a diary of their trip. Diary information will show us how many white crappie are caught compared to black crappie, and if there are any differences in habitat where anglers catch the two species.

(5) We will conduct an annual creel survey on Kentucky Lake to collect angler information regarding all types of fishing. So this study will help us assess the crappie population and other sportfish populations in the lake.

(6) Finally, we will be doing some extra electrofishing and netting in the spring. This will help us determine the accuracy of our annual fall netting data.

Past Studies

Since the mid 1990s, trap-netting data has indicated a change in species composition at Kentucky Lake. Prior to 1997, black crappie collected in trap nets made up only 18 percent of the catch, on average. Since that time, black crappie have made up 72 percent of the catch, on average. Why the change? We know that black crappie prefer clearer water, which we have had in the past few years. Black crappie also prefer aquatic vegetation, which we have.

So is this change in species dominance real? We hope to determine this and much more by doing some intensive sampling of the crappie population later this year. Although trap-netting data suggested a change in species dominance from white to black crappie, the harvest during the 1998 creel survey did not show this change. Black crappie made up 12 percent of the crappie caught and 17 percent of the harvest.

During the 1991 creel survey, black crappie made up 13 percent of the crappie caught and 16 percent of the harvest. So even though our trap nets were catching a higher percentage of black crappie in the late 1990s, anglers were still catching the same percentages of white and black crappie.

In 2001, our trap net studies revealed the number of crappie in the population is more than double the long-term average. But the majority of these fish were black crappie. This data suggests that the number of white crappie had declined, while the number of black crappie had greatly increased.

Our creel surveys showed that very few anglers caught black crappie. In spring 2002, most anglers caught very few crappie of any color. Some of the poor fishing experienced during that period was caused more by muddy water, water level fluctuations and cold fronts. So, if there are really all these black crappie out there and nobody is catching them, maybe we need to change the way we fish. Our fishing methods need to adapt to the changing reservoir just as the fish populations have.

These studies will help us answer many of these questions about black and white crappie, and their seasonal movements. It is our goal to pass this information along to you weekly.

Crappie Project Activity Log

February 28, 2003

Shoreline electrofishing collected seven crappie to be tagged with reward tags. Very few fish were shallow.

Week of March 3, 2003

Set 10 trap nets and utilized hook and line (fishing) to collect crappie. By the end of the week, we tagged 21 crappie with radio transmitters and 41 with reward tags. Water temperature was in the low 40s during the week. Water color was muddy, but clearing some by Friday. Fishing was slow, with fish being caught in 12-15 feet of water. Trap nets caught 362 crappie, of which 11 percent were keeper size. There were numerous 8- to 9-inch crappie in the lake. Approximately 60 percent of the catch was black crappie, and 40 percent white crappie.

Week of March 2-8, 2003

Between fishing 14 trap nets and the assistance of a few anglers we collected all the crappie to complete the radio tagging part of the study. We should begin tracking these crappie next week. Also, close to 200 crappie have been tagged with reward tags. For the week we collected from our trap nets a total of 1,129 crappie. Of these crappie, 10 percent were legal harvest size and 18 percent were white crappie. This spring netting supports our annual fall trap netting data, which suggest the crappie population consist of more black crappie than white. One interesting fact is that the anglers fishing in the shallow water of less than 10 feet were catching more black crappie, as were our nets. However, anglers fishing in deeper water — out toward the mouth of Blood River — were catching mostly white crappie. Water color this week cleared up some. Water temperature was in the low 50s by the end of the week. There was no pattern as far as the preferred bait, some used minnows others used jigs. Angler harvest was spotty, some anglers caught their limit, others only caught a few crappie. Everybody seemed to be catching small 8- to 9inch crappie, as well as our nets. Next week we will be catching crappie in other areas of the lake to tag crappie with reward tags.

Week of March 17, 2003

After surgically implanting radio tags in 30 black crappie and 30 white crappie, we removed our trap-nets from Blood River and set the trap-nets in Jonathon Creek on Monday, Tuesday and Wednesday. Our catch rates of black and white crappie were similar to catch rates in Blood River, with the majority of crappie collected in the nets being black crappie. The trap-nets were effective: on Wednesday alone, we collected more than 360 crappie in eight nets. We also managed to tag 354 crappie during those three days, including 149 white and 205 black crappie.

On Tuesday, we began collecting crappie by electrofishing, as a strong wave of crappie moved shallow. Most crappie were in 5 feet of water or less, and were around stumps, logs and stake beds. Every location with some form of structure was loaded with crappie. The interesting point was that we collected equal numbers of white and black crappie during our electrofishing samples.

Our crew also electrofished the Blood River that day and found similar results to our electrofishing in Jonathon Creek. More than 80 crappie were collected and tagged. All fish were collected around some form of structure in water shallower than 5 feet.

We began tracking our 60 radio-tagged fish in Blood River on Thursday and Friday. We located 36 of these crappie during those two days. Although crappie were scattered throughout Blood River, some interesting results were noted. A high number of male black crappie were found in shallow water, 5 feet deep or less. Fish were dispersed around structure and in the open on mud flats near river channels. Most of the female white crappie were located near the mouth of Blood River, in water 12 feet deep or more. They appeared to be relating to underwater stumps, brushpiles and stake beds. The highest concentration of fish were in water 12 feet deep or less, and were located from Sheep Ridge Pointi back to Crappie Hollow. One female white crappie was located back in Crappie Hollow in water less than 1 foot deep.

As this was our first tracking survey, no patterns can be established as of yet. However, we will continue tracking next week and hope that trends do begin to develop.

Anglers have already caught a total of four reward crappie (those with yellow tags). Currently, 770 crappie have been tagged. Our target goal is 1,500 crappie. We are halfway there and expecting to finish our tagging efforts next week. Take care and good fishing!

Week of March 23-29, 2003

This week was a slow one for tagging crappie. The crappie seemed to move back out into deeper water, which is just the place were we cannot collect them using electrofishing techniques. Our tracking information also indicated this move.

To date we have tagged 858 of the 1,500 crappie to be tagged, and there have been 34 crappie reward tags returned. Please return the yellow tags when you catch one of these crappie. The plastic yellow tag inserted into the back of these crappie are reward tags. To return these tags, you may use envelopes available at most marinas around Kentucky Lake and at the Wal-Mart stores in Murray, Mayfield and Benton. If you cannot get an envelope, call the phone number on the tag and we will mail you a return envelope. We prefer that you use our return envelope because it has a few questions that we would like for you to answer about the tagged crappie you caught.

We had a fairly successful week of tracking the 60 crappie with radio transmitters. We located 38 of these radio-tagged crappie. There were close to a dozen more we heard still beeping, but did not locate. We have received one radio transmitter back from an angler who had harvested one of these crappie. Please contact the Kentucky Department of Fish and Wildlife Resources if you catch a crappie with a thin steel wire extending out of the belly area. Please try to release these crappie back to the same area unharmed.

The tracking data suggest that 78 percent of the crappie are associating with a creek channel or flats near a channel. The movement from the previous week indicated fish were moving into deeper water and onto the flats. Very few fish were found in shallow water. The locations of both black and white crappie seemed to be very well mixed. There were no patterns noticed that one species was doing something different at this time.

Week of March 30 - April 4, 2003

Lake conditions this week have not been the most favorable for fishing. A 15-25 mph southwest wind made the lake a little choppy. Because of the wind, the water color was mud-stained in some areas. The water was clearer in areas more protected from the force of the wind. Water temperature was in the upper 50s. The water elevation is 355.5 fasl. This is about one foot higher than normal, based on TVA’s water level operations chart.

Creel survey information indicated that some anglers were able to catch a few crappie despite the wind. Survey results indicate anglers caught a high number of 8- to 10-inch crappie, as well as numerous crappie in the 1- to 2-pound range.

Only 65 crappie were tagged this week because of the wind and due to the fish moving into deeper water. However, we did find a few crappie in shallow brush piles. This brings the total number of crappie tagged to 917. Anglers have returned 71 tags from crappie since the start of the study.

High winds also delayed the tracking study of crappie implanted with radio transmitters. We found 21 of the 60 transmitter crappie during the one day of tracking this week. The majority of these crappie were oriented near the old creek channel in about 10-12 feet of water, or in the flats adjacent to the creek channel. No differences were seen between the movements of either the white or black crappie.

Week of April 6-11

Electrofishing on Monday and Tuesday (April 7-8) revealed that many crappie were moving shallower to stakebeds and shoreline brush. We tagged 70 crappie in the Blood River on Monday and 50 more on Tuesday. Since the study began, we have inserted small yellow tags (floy tags) into 1,064 crappie. We use these tags to help track fish, and anglers have caught and returned 53 of these tagged fish for a reward.

The majority of fish tagged this week were male white crappie, followed by male black crappie. Most of the female crappie remained in deeper water near river channels and flats adjacent to the river channels. Water temperature on Monday and Tuesday varied between 59 to 61 degrees.

A cold front passing through the area later in the week dropped the air temperature some 20 degrees. Wednesday’s high hovered in the upper 30s to low 40s, and we even experienced snow flurries throughout the day. Thursday brought slightly warmer weather. However, a strong north wind kept the Blood River area rather choppy. The cold front dropped water temperatures to the 55- to 58-degree range. As the front passed through, most of the fish apparently pulled away from the banks and gathered near adjacent flats. The lake continued to rise with Wednesday’s rain. By Thursday morning, the lake elevation rose to 358.13 and is expected to rise slightly on Friday (April 11).

Results from the radio telemetry fish showed that both black and white crappie appear to be occupying similar habitats. These are the fish implanted with radio transmitters to track their movements.

The majority of fish of the transmitter fish are staging in 6-12 feet of water near river channels and flats. On Tuesday, many fish were located in shallow water. The majority of these were male white crappie. Several fish have even begun to journey back into the shallower "Crappie Hollow" area as a result of rising water levels. A few fish were still found near the mouth of Blood River in 15-plus feet of water; however, the majority of the radio telemetry fish are now between Sheep Ridge Point and "Crappie Hollow." Tracking on Thursday showed that a few fish had moved significantly since Tuesday, although the majority still remained near their previous location. We even had one of our radio-tagged fish caught right in front of us while we were tracking it.

We ask all anglers to return transmitter fish to the water immediately. These fish have a wire protruding from their stomach. If we can keep these fish in the water, we can better track crappie movement.

Overall results from tracking this week appear to show us that many male white and black crappie have begun to move shallow near stakebeds and shoreline brush and timber. This suggests crappie are beginning to prepare nests for spawning. Most of the female crappie are still being found in deeper water near river channels and adjacent flats. Several anglers reported good catches of crappie using jigs and minnows fished under bobbers in shallow-water stakebeds. Other anglers report good catches of crappie by casting jigs to the bank. Hopefully better weather will arrive next week, which should begin to push the majority of crappie shallow in preparation for the spawn that is fast approaching.

Good Fishing.

Week of April 13-18

Tracking results from crappie implanted with transmitters showed for the first time since the study began that black and white crappie appear to be doing their own thing. This week we tracked more black crappie (mostly males) in shallow water in the back of Blood River and into the backs of several smaller embayments. This would indicate that the males have moved shallow to locate and prepare nesting sites.

I would report that fishing has been good this past week. However, two cold fronts brought lots of wind and the lake elevation dropped almost one foot — putting a damper on fishing success. Monday’s lake elevation of 358.9 feet dropped to 358.3 by Thursday (April 17). The prediction for Easter weekend is stable at 358.4 feet, which is still more than a foot above normal.

The water temperature is in the mid-60s. Water color is good in some bays and clear in the more northern embayments. A suggestion for fishing clear water is to anchor off the shoreline, or area to fish, and cast to it.

Last week, we finished tagging crappie with floy tags, which resemble a strand of yellow spaghetti protruding from the top of the fish. We tagged a total of 1,065 crappie, of which 51 percent were white crappie and 49 percent were black crappie. By April 17, anglers had returned tags from 13 percent (or 143) of the fish marked during this year’s study. Of those returned tags, 54 percent came from white crappie and 46 percent came from black crappie. We are now 40 days into this year’s project.

In 1988, a similar study was conducted on Kentucky Lake with 998 tagged crappie. After 40 days, 11 percent, or 114 tags, were returned by anglers. Fifty percent were from white crappie. What does this tell us? Angler harvest of white and black crappie has not changed much in 15 years, even though we have seen a big increase in the population of black crappie during this period.

The creel survey being conducted on Kentucky Lake this year is telling us a different story about the harvest of white and black crappie. Seventeen crappie anglers checked in the first part of March revealed they had a combined catch of 65 crappie, of which 94 percent were white crappie. Thirty-five crappie anglers checked in mid-March revealed a combined catch of 136 crappie, of which 78 percent were white crappie. And, the 72 crappie anglers fishing the last week of March and into the first week of April had a combined catch of 310 crappie, of which 88 percent were white crappie. Fishing success did increase from March into April, which is to be expected. As crappie move shallow to spawn, they become more susceptible to being caught.

April 20-23 (mid-week report)

Electrofishing surveys conducted this week showed crappie are very shallow. The majority of the crappie seen in shallow water were male crappie, probably guarding nests. These fish were found around shoreline habitat such as willow trees, buttonball bushes, water willow and submerged mustard flowers.

Sampling around stake beds and brush piles in 5-8 feet of water yielded few crappie. The crappie that were collected were both male and female. About half of the female crappie appeared to have already spawned. Some had eggs oozing out while others still had the majority of their egg pouch.

Crappie implanted with radio transmitters were also tracked to similar locations as indicated by the electrofishing. Several of the male crappie were very shallow and found near shoreline vegetation. A few crappie were found on flats around stumps in about 5 feet of water. There were also a few crappie found on ledges in deeper water along the creek channels.

Given the electrofishing and tracking information, crappie are definitely spawning. The spawn, however, can last a few weeks. Anglers should try fishing around shoreline habitat. Clear water and rough water conditions make this type of fishing difficult without spooking the fish. One practical way to fish this habitat is without a boat. Try wading with hip boots or chest waders, and use a cane pole and bobber.

The current water elevation is 358.8 fasl. The water temperature is in the mid-60s. The recent cold front will probably slow fishing, as will the severe storms predicted for Wednesday night and Thursday.

April 20-25 (full week report)

Crappie are still in the shallows. Electrofishing (shocking) performed this week revealed a few female crappie in the shallows, but the majority of fish near the banks were male crappie, both black and white.

These males are likely guarding nests and pursuing females. All fish were found amongst buttonball bushes, willow trees and submerged mustard flowers. Although several crappie were also collected from stake beds, the highest concentration of fish continue to be found near shoreline vegetation and timber.

It appears the spawn began last week and continued this week. Spawning likely will continue for another week or two, but the biggest pulse is probably finished. Male crappie should remain shallow for the duration of the spawn, while many of the female crappie that have already spawned are making their way to adjacent flats and river channels. Female crappie should feed aggressively while they recuperate from the spawn.

Casting shoreline structure with jigs, minnows and small crankbaits should produce nice catches of male crappie. The key is to get your bait into the flooded timber and vegetation where the fish are hiding. Drifting and casting flats, points and river channels will likely produce catches of females.

Radio telemetry (fish tracking) surveys performed Tuesday, April 22, showed the majority of male and female crappie remained close to the shore, particularly around vegetation and flooded timber. Black crappie were further back in Blood River and smaller bays than white crappie. On average, black crappie were also found in much shallower water than white crappie. Males apparently are remaining closer to shore — guarding and preparing nests — while most of the females were in deeper water. Within the Blood River area, the highest concentrations of radio telemetry fish were located in the area from Wildcat Boat Ramp to Crappie Hollow.

We also conducted 24-hour tracking of eight crappies this week in order to follow their movements during an entire day. We recorded some interesting information. Although we have not fully analyzed the data, it appears that females moved more during the course of a day than the males. This seems likely, since most males are guarding nests while females are spawning then leaving the area.

We tracked one female black crappie that moved more than 3.5 miles in 24 hours. She eventually returned to the area where she was first found. Overall conclusions of the 24-hour track were that both male white and black crappie moved little and were consistently found amongst flooded timber. Females were found in deeper water than males, although they remained near shoreline habitat. An interesting note: few male crappie were spooked away from their nests as a result of us getting close to them with our tracking boat. This indicates these fish are being good parents and effectively guarding the developing eggs.

Many anglers reported a difficult week of crappie fishingi compared to last week. This may be because many of the crappie are not interested in feeding while they are spawning. Also, males guarding nests will probably not travel far to feed. You must get your lure near the front of the fish before they will eat it. Anglers reported better catches prior to the heavy thunderstorms that arrived in the area Thursday and Friday (April 24-25). Many of these crappie were caught early in the day and in shallow water around flooded bushes.

This week’s heavy rains will likely cause the lake to rise, unless gates are opened at the dam. The rain stained water in the Blood River area, which should help anglers fishing shallow (allowing people to get closer to the fish before spooking it). The lake elevation at 8 a.m. Friday (April 25) was 359.8 fasl. Water temperatures remained in the upper 60s.

Week of April 28-May 2

Crappie are still in the shallows. Electrofishing (shocking) performed this week at Lake Barkley revealed many crappie were still in the buttonball bushes and willow trees along the shoreline. Conditions at Lake Barkley are generally the same as those on Kentucky Lake.

Spawning likely will continue for another week, but the biggest pulse is probably finished. Male crappie should remain shallow for the duration of the spawn, while many of the female crappie that have already spawned are making their way to adjacent flats and river channels.

Radio telemetry (fish tracking) surveys performed Monday and Tuesday (April 28-29), showed the majority of male and female crappie remained close to the shore, particularly around vegetation and flooded timber. Tracking was attempted on Friday, but poor weather prevented us from finding many fish. It seemed that some of the fish that were in the bushes early in the week had moved onto adjacent flats.

Many anglers reported a difficult week of crappie fishingi compared to a few weeks ago. This may be because many of the crappie are not interested in feeding while they are spawning. Also, males guarding nests will probably not travel far to feed.

Lake elevation on Friday (May 2) was near 359.3. During the week there was a minor drop in the water level. However, it has come back up. Water temperature is in the low to mid-70s. Water clarity is clear in most areas of the lake.

Week of May 5-9

Heavy rain and rising water are having an impact on the lake. On Friday (May 9) the lake was muddy, 71 degrees and two feet above normal pool. The lake will rise another five feet during the weekend of May 10-11.

Radio tracking surveys performed this week shows most black and white crappie — both male and female — are hiding in shoreline bushes and shallow flooded timber. Of 21 crappie equipped with radio transmitters for this study, only one was found in deep water (15 feet). The rest of the fish were located in water less than three feet deep.

Approximately half of the study fish tracked this week remained in the same area. The remaining fish moved somewhat, but remained in the same type of habitat and water depth. Crappie are following the rising water into newly flooded cover, such as trees and bushes. Several fish have been located in shallow water between flooded tree trunks and the shore.

Week of May 12-19

Throughout the week of May 12th, rising water levels continued to dominant Kentucky Lake. The lake went from 364.5 on Monday (5/12) to 367.00 by the end of the week. This resulted in even more flooded vegetation and trees for crappie to hide in and forage feed heavily. Similar to our previous weeks results, all of our crappie remained in and among the flooded trees, bushes, and vegetation. The farther into the trees, bushes and vegetation you can get, the better your chances of catching one of the fish implanted with radio transmitters.

By the end of the week, we started to see signs of declining water levels, mostly due from a much needed relief in the amount of rain we are getting. With the declining water levels and break from the rain, crappie continued to remain shallow amongst the flooded vegetation and bushes. Again, similar to our previous week’s data, we are finding more of our black crappie further back in "Crappie Hollow" and in the back of Sugar Creek, while the majority of our white crappie seem to be utilizing shoreline habitat from "Fannin Point" out to "Sheepridge Point."

Not many crappie anglers were seen in Blood River throughout the week. Those fishing in Blood River report fair catches of both white and black crappie. Many of them are flipping small jigs in the bushes, using bobbers and minnows, and trolling small jigs around the outside edges of flooded bushes and trees. A few anglers trolling on the flats and river channels report catches of large white crappie on crankbaits being trolled for white bass. Water temperatures have not drastically increased from the previous week and still remain in the mid-70's.

May 27-June 3

With the return of normal water levels to the Blood River area of Kentucky Lake, we anticipated a gradual migration of crappie out of the flooded shallows to the secondary and primary river channels. However, many of our fish continue to remain in the same areas that they have been inhabiting during the higher water levels.

We are still finding the majority of our crappie between Sheepridge Point and Fannin Point. The large flat immediately south of Fannin Point continues to harbor the greatest concentration of white and black crappie. Fish are staying near the river channel that meanders through this area. Several other fish in the area are also relating to the flooded shoreline vegetation and brush.

We are still seeing more black than white crappie further back in the Crappie Hollow area. Most of our white crappie are staying along shoreline brush and open water flats in the middle section of Blood River. A few female white crappie have moved off the banks and relocated in 12 to 22 feet of water, along the old river channel that runs through Blood River.

There appears to be no difference between black and white crappie preferences when it comes to water clarity or surface water temperature. Surface water temperature has been relatively stable around the lower to mid-70s. Temperatures may dip further because of the unseasonably cool weather earlier this week.

Few crappie anglers are on the water. Those still fishing for crappie report incidental catches of large crappie while trolling small crankbaits for white bass. A few crappie anglers are still catching fish on jig and minnows in shallow areas near brush and stakebeds.

As our project approaches its halfway point, we are still getting continuous data on approximately two-thirds of the crappie implanted with radio transmitters. We have not been able to locate seven white crappie and 12 black crappie for the past month. There are three possible explanations:

The fish left the Blood River area for the main lake. We will perform a tracking study on the main lake soon to test this theory.
The transmitter failed and we can no longer pick up a signal.
An angler caught the fish and removed it from the lake.
If you have one of our radio transmitters, please contact us at (270) 753-3886 so that we can pick it up from you. The transmitter has a foot-long wire antenna and a thumbnail-sized unit implanted in the fish.

This project only works if we can collect as much data as possible during the short study period. If you do keep a radio telemetry (transmitter) fish, we can put its transmitter into a new fish and begin collecting new data if the equipment is returned to us. Again, we thank everybody for their patience during this project.

June 20-25

The hot days of summer have finally arrived and are here to stay. Air temperatures hovered in the mid-90s while surface water temperatures ranged from the low to upper 80s in Blood River during our last two tracking surveys. The lake elevation is still high, ranging around 359.2 to 359.35.

Our radio-tagged fish are finally moving. Although most of these crappie are located between Sheepridge Point and Fannin Point, they have started to move deeper. Some crappie previously found around brush and stumps in 3-5 feet of water have now moved to the first major drop-off adjacent to the structure. Most of our larger female white crappie have moved out towards the river channel, with some found in 22 feet of water. The area out from Sheepridge Point, where numerous ledges and the meandering river channel can be found, held several fish this week, mostly white crappie.

The greatest concentration of black crappie remain in the area stretching from "Crappie Hollow" to Fannin Point. Most white crappie are being found from Fannin Point to Sheepridge Point. On Tuesday (June 24), most fish were relating to the river channel that meanders through that area, or the flats that lie adjacent to the river channel.

Several crappie remain shallow near submerged brush and stake beds despite the gradual overall movement toward deeper water. A few crappie on Tuesday (June 24) were found among flooded willow trees, presumably feeding on the recent hatch of mayflies (willow flies) that occurred on Sunday and Monday.

Few crappie anglers are fishing the Blood River. White bass anglers trolling small crankbaits near ledges and river channels are catching most of the crappie. A few crappie anglers using jigs and minnows reported decent catches of 15-inch fish in water over 15 feet deep.

Information provided by Kentucky Department of Fish and Wildlife Resources

Minn-Kota i-Pilot Remote Quick Reference

The i-Pilot is a GPS-enabled replacement head for current Minn-Kota electric drive bowmount trolling motors, including the Terrova, Powerdrive V2, and Riptide ST/SP motors.

Wheeler Reservoir Crappie Management Report 2007

Prepared By Keith B. Floyd District Fisheries Supervisor Phil D. Ekema District Management Biologist And Glenn R. Selby Biologist aide I/II Fisheries Section Division of Wildlife and Freshwater Fisheries Department of Conservation and Natural Resources February 22, 2008



The reservoir management objective for Wheeler Reservoiri is to collect baseline biological data on the important sport fishes. From this data, length-at-age frequencies, growth, relative abundance and relative weight or condition will be obtained. This information will be analyzed and used to formulate management recommendations.

Wheeler Reservoir has been sampled routinely since 1994. Attempts at sampling crappiei populations with standardized methods have produced limited results. Due to the limited catch efficiency of trap nets on Wheeler Reservoir, we decided to sample crappie in the fall of 2007 by electrofishing.


Wheeler Reservoir was sampled on October 24 and 26 adjacent to the causeways, second creek and Elk River embayments. Samples were collected from Limestone Creek and Flint Creek embayments on October 29 and 30, respectively. All crappie collected were sexed, weighed and measured. Otoliths were removed from all crappie greater than 100mm total length (TL) for aging. Data analysis was conducted using Alabama Division of Wildlife and Freshwater Fisheries (ADWFF) Data Analysis and Report Utilities (Slipke, 2004). White crappie and black crappie were analyzed separately.


A total of 110 white crappie was collected in the fall. All fish were associated with woody debris structure in depths ranging from 2 to 10 feet. Also, at the time of collection, crappie were being caught by anglers along open water structure, including creek channels and drop-offs (personal observation) at depths ranging from 5-15 ft. deep. Many of the angler caught fish were suspended at various depths in the open water. This spatial distribution has been observed in other reservoirs where trap nets are ineffective at collecting crappie but angler catch rates are high (personal observation).

Relative Stock Density (RSD) calculations revealed that the preferred and memorable categories were above the statewide 75th percentile for trap nets and dominated the sample. The stock and quality size categories were below statewide means for trap nets and at or below the 25thpercentile. This is probably to be expected due to the size selectivity that can occur with electrofishing gear. Growth of white crappie is very rapid with the majority of one year olds exceeding nine inches.

Age distribution was acceptable with seven year classes (0-6) represented (Table 3).

Age 0 and age 1 dominated the sample comprising 72% of the fish collected. From catch curve regression, calculated annual mortality (A) was 56% and year class strength was fairly uniform with no weak or exceptionally strong year classes present (Figure 3).

Calculations on conditional (cm) and instantaneous (M) mortality from FAST modeling program (Slipke and Maciena, 2006) ranged from 0.56-0.3 for cm and 0.82-0.35 for M. Average cm value is 0.44 and average M value of 0.59. Estimated exploitation rate for white crappie is 16%, with a natural mortality rate of 40%.

Thirty-four black crappie, representing four year classes were collected during fall electrofishing. Age distribution was similar to white crappie in that the majority of the sample were age 1 and age 2 (Table 4). Incremental RSD values were 45% for quality, 42% for preferred and 6% for the memorable RSD categories. These values were all above the statewide averages for black crappie collected using trap nets. The RSD stock value of 6 was well below the statewide mean. These high values are probably a result of electrofishing bias for larger size groups. Growth was slightly slower than observed for white crappie, but the mean length-at-age was higher than statewide means (Damon Abernethy, personal communication). Black crappie from Wheeler Reservoir exhibit above average growth rates.


The white crappie and black crappie population on Wheeler Reservoir shows excellent size distribution and age structure. Currently we do not have an explanation for the rapid growth rates. Other reservoirs in North Alabama show rapid growth rates of crappie, e.g. Smith and Pickwick. The low estimated exploitation rate, satisfactory age and size distribution and fast growth rates would indicate that no change in management strategies are warranted at this time.

Literature Cited

Jenkins, R. M. 1967. The influence of some environmental factors on the standing crop and harvest of fishes in U. S. reservoirs. pp. 291-298 in Reservoir Fisheries Resource Symposium. Southern Division American Fisheries Society, Bethesda, Maryland, U.S.A. Ryder,

R. A. 1965. A method for estimating the potential fish production of North-American temperate lakes. Transaction of the American Fisheries Society. 94:214-218.

Slipke, J.W. and M.J. Maceina. 2006. Fisheries analysis and simulation tools (FAST). Auburn University, Auburn, Alabama.

Slipke, J.W. 2004. ADWFF data analysis and report utilities. Version 2.2. Auburn University, Auburn, Alabma.

Welch, P. S. 1948. Limnological methods. McGraw-Hill. pp. 93-94.

Table 1
Table 2
Table 3
Table 4
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7

White Crappie

White Crappie (Pomoxis annularis)

Drawing of White Crappie (Pomoxis annularis)

Illustration © TPWD

Other Names
White Perch, Sac-a-lait
Pomoxis is Greek for "opercle sharp" and refers to the fact that the fish's gill covers have spines. The word annularis is Latin for "having rings" and refers to the dark bands (vertical bars) around the body. The white crappie is deep-bodied and silvery in color, ranging from silvery-white on the belly to a silvery-green or even dark green on the back. There are several vertical bars on the sides. The dorsal fin has a maximum of six spines. Males may develop dark coloration in the throat region during the spring spawning season.
Life History
Like other members of the sunfish family, white crappie are nest builders. They are similar to bluegills in that they tend to nest in relatively large "beds", and they have very high reproductive potential which often leads to overpopulation and stunting in small lakes and impoundments. White crappie nest in the spring, generally when water temperatures reach 65°F to 70°F. However, spawning activity has been observed at temperatures as low as 56°F. Fry hatch in three to five days, but remain attached to nest substrate by an adhesive substance from the egg for a few more days. Just before leaving the nest, fry free themselves by vigorous swimming actions. Once free, they begin feeding on microscopic animals. Although fry do not appear to school, fingerlings do. Schools with large numbers of individuals are often found in the middle of lakes. Typically, white crappie grow three to five inches in length the first year, and reach seven to eight inches during the second year. Maturity is usually reached in two to three years. Adults feed on small fish and insects.
The native range of white crappie included the area west of the Appalachian Mountains north to southern Ontario and south to the Gulf of Mexico. The range extended west to Minnesota and South Dakota in the north, and to northeastern Mexico in the south. Today the range extends east to the Atlantic coast, and west to include California and portions of Nevada, Arizona, New Mexico, Montana, Colorado, Utah, and North Dakota. White crappie are native to the eastern two-thirds of Texas, but the species can now be found statewide except for the upper portions of the Rio Grande and Pecos drainages.
Taken together, "crappie" (white and black combined) is the most popular panfish in Texas. The crappie group is the third most preferred group overall, ranking behind only "bass" and "catfish." Crappie are sought after by both bank and boat anglers. Typically, minnows are the preferred bait, often producing monumental results when an aggregation is located, usually around submerged trees, boat docks, or other submerged structures. White crappie in excess of 4.5 pounds have been landed in Texas waters.

For more information, please visit Information and Photos courtesy Texas Parks and Wildlife Department

i-Pilot Owner's Manual - Rev. D

This i-Pilot user Guide is divided into four main sections: Installation, Getting started, Manual Control, and GPS Motor Control. A French version of the manual is available online at