Crappie Populations Research Articles

Size Selectivity of Crappie Angling

Abstract Over 6,000 black crappies Pomoxis nigromaculatus and white crappies P. annularis were tagged in five lakes and reservoirs to quantify size selectivity of angling. Total length of fish tagged ranged from 20.0 to 39.8 cm; fish caught by anglers ranged from 20.0 to 38.8 cm. Return rates were low at lengths near 20 cm, increased gradually to a peak between 26 and 32 cm, and decreased for longer fish. This pattern was consistent among the five lakes and reservoirs and did not differ between species. Observed size-selective exploitation resulted in the lopsided removal of intermediate age-classes, thereby simulating a reversed slot length limit. Crappie population dynamics and fisheries can be severely affected if angling selectivity and exploitation are high. Management of crappies to favor desirable population characteristics may need to focus on enhancing or weakening the effect of size selectivity.

Comparison of Trap Nets and Otter Trawls for Sampling Black Crappie in Two Florida Lakes

We compared the effectiveness of a recreational shrimp trawl (used for Penaeus spp.) with that of trap nets for assessing populations of black crappie Pomoxis nigromaculatus. Lakes Griffin and Monroe were sampled with both gears simultaneously during Oct–December 1997. Coefficients of variation (CV = 100 × SD/mean) on mean catch per effort (CPE) values ranged from 105 to 161 for trap nets and from 62 to 96 for trawls. Both trawls and trap nets collected fish less than 150 mm total length (TL), but trawls sampled significantly more adult fish (>250 mm TL). Variable catches in trap nets would require more sampling effort than trawl sampling (up to 4 times as much) to obtain precise estimates of mean CPE. Trawl sampling was preferable to trap nets based on size of fish captured, precision of abundance estimates, cost of the gear, and required sampling effort to estimate mean CPE. However, trawl sampling may be impractical in water bodies with excessive submerged structures, debris, and submersed macrophytes. We are encouraged by the effectiveness of the trawl for assessing black crappie populations in lakes where it is possible to sample with a bottom trawl.

An age-structured model for erratic crappie fisheries

White crappie Pomoxis annularis and black crappie P. nigromaculatus are important freshwater sportfishes in North America. Because of erratic recruitment (the number of fish that survive to age 1 each year) fishery yields are inconsistent. We developed a simple age-structured model to help manage crappie fisheries. The model changes population biomass by age-specific somatic growth, and population abundance through recruitment and age-specific natural and fishing mortalities. Using empirical stock-recruitment data and a stochastic component to simulate the effects of abiotic environmental fluctuations on recruitment, the model simulated empirical recruitment dynamics of a crappie population over 30 years in a large impoundment. Effects of density-dependent growth and natural mortality were modeled, but did not substantially affect the yield given the observed magnitude of recruitment fluctuations. Model predictions of population biomass and yield tended to be high relative to empirical estimates, but not unrealistic. Erratic recruitment of crappie populations has made development of management strategies elusive. This model should help fishery managers examine potential management alternatives.

Comparison of Triploid Hybrid Crappie and Diploid White Crappie in Experimental Ponds

Abstract We crossed female white crappies Pomoxis annularis with male “black-stripe” black crappies P. nigromaculatus to yield hybrids possessing a distinct coloration that may serve as a natural tag when fish are introduced into existing crappie populations. Eggs of these hybrids were cold shocked to produce triploid hybrid crappies. In three spawns, the black stripe was expressed in 100% of hybrids that were not cold shocked and 85% of hybrids that were cold shocked. Coldshocked hybrids were 95% triploid and 5% diploid. Triploid hybrids bearing the black stripe and diploid white crappies without the black stripe were stocked into experimental ponds for growth and survival comparisons. There were inconsistent differences in growth, body condition, and survival of triploid hybrids and diploid white crappies after 1,151 d in ponds, but the gonads of triploid hybrids were consistently smaller than those of diploid white crappies for each sex. No reproduction was observed in ponds with triploid hybrids, wher...

Effects of Variable Recruitment on Catch-Curve Analysis for Crappie Populations

Abstract Catch-curve analysis is frequently used to estimate total annual mortality (A) of exploited fishes, but the method assumes constant recruitment. Because populations of crappie Pomoxis spp. have exhibited large fluctuations in recruitment, I conducted simulations to assess the amount of variability in recruitment that precludes the use of a catch curve and compared results to recruitment dynamics in six crappie populations. Coefficients of variation (CV = 100.SD/mean) in recruitment to age 1 ranged from 55% to 84% among the six crappie populations. Simulations suggested that recruitment variability in these ranges would likely allow estimation of A within ± 10%, but the probability of obtaining estimates of A that were ±5% or more of the true A would exceed 0.15. 1 suggest that catch curves may be used to approximate A in crappie populations but that managers should consider the effects on management recommendations if A were ± 10% of the estimated A.

Influence of Size at Stocking on Survival of Saugeye in a Northern-Latitude Impoundment

ABSTRACT The saugeye [walleye (Stizostedion vitreum) X sauger (S. canadense)] has been used effectively as a predator to reduce recruitment and improve growth and size structure for overabundant crappie (Pomoxis spp.) populations. Saugeye were stocked into 336-ha Richmond Lake, South Dakota, an impoundment that contained an overabundant black crappie (Pomoxis nigromaculatus) population. Small fingerling (circa 3–4 cm) stockings in 1992 and 1993 had relatively low survival; fall electrofishing catch per unit effort (CPUE) values for age-0 saugeye were 5/hr and 3/hr. In 1994 and 1995, larger (circa 14–19 cm) fingerlings were stocked, and fall CPUE values were 185/hr and 33/hr. In addition, the fingerlings stocked in 1994 were collected during fall 1995 electrofishing as age-1 fish at a rate of 41/hr. At northern latitudes, small fingerling saugeye grow slowly and likely remain vulnerable to predation by and competition with overabundant black crappie populations. Stocking larger saugeye fingerlings may over...

Comparison of Catch per Unit Effort and Size Structure of White Crappies Collected with Trap Nets and Gill Nets

Abstract White crappies Pomoxis annularis were collected from 13 Kansas reservoirs with trap nets and horizontal gill nets. Ten of the reservoirs were sampled concurrently for two or more years. Our objective was to determine if catch per unit effort (CPUE)—the number of stock-length (≥13-cm) white crappies captured per trap-net-night or per gill-net-complement-night—and size structure—indexed by measures of stock density—differed between trap nets and gill nets. We found no significant relation between trap-net and gill-net log10(CPUE). Conversely, size structure of white crappies was similar between gears. Proportional stock density (PSD) and relative stock density of preferred-length fish were positively correlated between gears. Relative stock densities by length category were also significantly correlated between gears. These data indicate that the two gears likely would give similar information about changes in white crappie population size structure, but disparate information about the species' rel...

Threadfin Shad Use as Supplemental Prey in Reservoir White Crappie Fisheries in Kentucky

Abstract Prey bases in two Kentucky reservoirs were supplemented with stocked prespawn adult threadfin shad Dorosoma petenense during 1991–1993 to improve fisheries for white crappies Pomoxis annularis by increasing their growth and shifting population size structure toward larger fish. Abundance of age-0 threadfin shad produced was lower than native age-0 gizzard shad D. cepedianum, but threadfin shad provided late-season prey by spawning later than gizzard shad in both reservoirs. In Rough River Lake, threadfin shad stocking rates of 15–28 fish/ha produced peak densities of 0.04 ± 0.01 to 0.46 ± 0.10 fish/m3 (mean ± SE) that represented 3. 5, and 0.3% of the annual peak gizzard shad densities from 1991 through 1993, respectively, but neither white crappie growth nor population size structure were improved. In Dewey Lake, threadfin shad stocking rates of 121–285 fish/ha produced peak threadfin shad densities of 0.40 ± 0.15 to 0.66 ± 0.08 fish/m3 that represented 89, 23, and 20% of peak gizzard shad densi...

Population Characteristics of Black Crappies in South Dakota Waters: A Case for Ecosystem-Specific Management

We sampled 22 populations of black crappie Pomoxis nigromaculatus from three ecosystem types (large impoundments, >40 ha; small impoundments, ≤40 ha; natural lakes) to determine the factors that influence population characteristics (recruitment, growth, size structure, and condition) in South Dakota. Recruitment variability was best correlated with the log10 of the shoreline development index (r = 0.63, df = 16) and the log10 of the watershed : lake area ratio (r = 0.89, df = 12). Mean back-calculated length at age was highly variable among ecosystems and was inversely correlated with the log10 of the catch per unit effort (CPUE; r = –0.35 to –0.69). Mean back-calculated length for all ages was positively correlated with mean relative weight (r = 0.48–0.78, df = 18-21). Proportional stock density and relative stock density of preferred-length fish were inversely correlated with log10 CPUE (Spearman correlation, rs = –0.31 to –0.83, df = 21) and were positively correlated with growth of black crappies (rs = 0.55–0.73, df = 18–21 ). Bivariate centroids differed significantly (P ≤ 0.05) among ecosystems for canonical analysis; canonical factor scores were derived from growth, recruitment, CPUE, and condition. These data suggest that black crappie population characteristics differ among ecosystems. Natural lakes typically had black crappie populations with low density, unstable recruitment, fast growth rates, and high condition factors. Conversely, small impoundments had black crappie populations with high density, more stable recruitment, slow growth, and low condition factors. Black crappie population characteristics in large impoundments were typically intermediate between those of natural lakes and small impoundments. The differences observed in recruitment variability, growth, size structure, and condition of black crappie populations among ecosystems facilitate a better understanding of the factors that influence these variables and illustrate the importance of ecosystem-specific management.

Influence of Angler Exploitation on Black Crappie Population Structure in a Rural South Dakota Impoundment

ABSTRACT Anglers harvested approximately 122 black crappies (Pomoxis nigromaculatus)/ha at 18-ha Murdo Lake, South Dakota, in 1992. Based on a mean length of 26.2 cm for harvested black crappies, anglers likely harvested 36.1 kg/ha. The following spring (1993), proportional stock density (PSD) for black crappies collected with trap nets was 10—far lower than for any of the previous four years. Thus, we conclude that angling can have a substantial effect on the black crappie population in a small impoundment.

Hybridization and Biochemical Genetics of Black and White Crappies in the Southeastern USA

Populations of black crappie Pomoxis nigromaculatus and white crappie P. annularis in Alabama, Arkansas, and Tennessee were examined for isozyme variation. Twelve diagnostic loci distinguished these two species. Both species exhibited low levels of genetic variation. Percentages of loci polymorphic in populations of black and white crappies were 0–4.7% and 0–11.6%, respectively. Mean heterozygosities were 0.000–0.008 and 0.000–0.012 for black and white crappie populations, respectively. Although extremely low levels of genetic variation were detected within or among white or black crappie populations when only nonhybrid individuals were considered, there were some distinct differences among populations within each species. Populations in Tennessee tended to have a greater number of unique, low-frequency, variant alleles than other crappie populations. Black crappies possessing the blacknose trait had allele frequencies similar to those of black crappies with normal coloration. Natural hybridization was common between the two species and was the major source of genetic variation. The extent of hybridization varied among reservoirs and hatcheries. In three of eight sites sampled, 29.3 to 54.5% of the individuals were F1 or Fn hybrids (n = 2, 3, …); F1 hybrids were more likely to be found in reservoirs than in hatcheries, and Fn hybrids were found in both reservoirs and hatcheries.

Growth, Survival, and Recruitment of Hybrid Crappies Stocked in Small Impoundments

White crappie Pomoxis annularis and black crappie P. nigromaculatus are popular sport fish, but because of erratic recruitment they are difficult to manage and generally are not recommended for stocking in small impoundments. We examined the growth, survival, and recruitment of interspecific F1 hybrid crappies stocked in ponds with established predator and prey populations, to determine if they were more amenable to management in small impoundments than their parent species. The F1 hybrids had lengths at age similar to those of white crappies through age 5. Survival of the stocked F1 hybrids was low, especially beyond age 1. Recruitment was also low; none of the stocked hybrid crappie populations were capable of maintaining their initial densities. Because their recruitment is low and they have growth rates similar to their parent species, we believe hybrid crappies provide a viable alternative to stocking white and black crappies in small impoundments. Before more specific management recommendations can be developed, additional research is needed to identify the factors influencing recruitment of hybrid crappies under a range of natural conditions.

Natural Hybridization between Black Crappie and White Crappie in Weiss Lake, Alabama

Starch-gel electrophoretic analysis of 1,081 crappies collected from October 1990 through November 1991 revealed that black crappie Pomoxis nigromaculatus and white crappie P. annularis were hybridizing in Weiss Lake, Alabama. Crappie hybrids made up 22% of the population and were found in the 1988 to 1991 year-classes. First-generation (F1) hybrids were seven times more abundant than second-generation and higher (Fx) hybrids. The F1 hybrids expressed superior growth and survival, and they recruited into the fishery (254-mm total length minimum size limit) earlier than the parental species. Distributions of alleles among Fx hybrids indicated that F1 hybrids were more likely to successfully mate and produce offspring with black crappies than with white crappies. Factors that may have contributed to hybridization between crappie species include failure to identify specific mates due to low water clarity during spring when these fish spawn, short and overlapping spawning times, and fluctuating water levels. In addition, Weiss Lake is located at the interface of sympatric and allopatric crappie populations and this has been associated with interspecific hybridization among other fish species.

Comparison of Otolith and Scale Age Characteristics for Black Crappies Collected from South Dakota Waters

Abstract Scales and otoliths (sagittae) were collected from black crappies Pomoxis nigromaculatus sampled during the spring of 1991 in Red Plum Reservoir and Roy Lake, South Dakota. Red Plum Reservoir contained a slow-growing black crappie population, whereas Roy Lake had a fast-growing population. Annuli in scales and otoliths were identified independently by three readers. Within-structure (i.e., among-reader) and between-structure agreements in both population samples were 94% or greater for both scales and otoliths from fish of all ages. Our results indicated that for black crappies from South Dakota waters, precision of ages determined from scales and otoliths was similar.

Population structure and food habits of white crappie Pomoxis annularis Rafinesque in a turbid Oklahoma reservoir

We assessed population structure and food habits of white crappie Pomoxis annuluris Rafinesque in Lake Carl Blackwell, a turbid reservoir in north‐central Oklahoma, U.S.A. White crappie [n= 8549; total length (t.l.) mean = 147 mm, s.d.= 28 mm, range = 73–445 mm] were collected with gillnets, frame nets, and hoop nets. Proportional stock density was 2, as 97% of the fish were under 200 mm t.l. Relative stock density was 96, 2, 1, and 1 for ‘stock‐quality’, ‘quality‐preferred’, ‘preferred‐memorable’, and ‘memorable‐trophy’ lengths. Total annual mortality rate was 54% for fish older than 2 years. Growth was poor and lower than the Oklahoma‐Arkansas regional averages (P<0.01). Relative weights were 79, 86, 106, 109, and 123 for fish in the stock‐quality, quality‐preferred, preferred‐memorable, memorable‐trophy, and trophy size categories. Ephemeroptera nymphs were an important dietary component for fish 150 mm t.l. or smaller. Gizzard shad Dorosoma cepedianum (Lesueur) was a major forage item, especially for fish greater than 150 mm t.l. (P<0.01). Empirical information on prey availability indicates that the white crappie population is forage limited and that gizzard shad are not available in appropriate sizes or sufficient numbers to sustain the predator population. Poor fish condition, slow growth, and high mortality are probably the result of inadequate forage.

Evaluation of Minimum-Size Limits and Reduced Daily Limits on the Crappie Populations and Fisheries in Five Large Missouri Reservoirs

Populations of white crappies Pomoxis annularis were studied at five Missouri reservoirs to evaluate the effects of minimum-size regulations and reduced daily limits. Models of equilibrium yield per recruit indicated that regulations that reduced or eliminated the harvest of age-1 and age-2 fish resulted in harvest of fewer fish but increased yield to the fishery. Peak yield occurred when white crappies were first harvested at age 3. After restrictive regulations were imposed, a significantly greater proportion of the harvest shifted to age-3 and older fish at Pomme de Terre (15-daily limit), Wappapello (10-daily limit), Stockton (10-in size limit), and the James River Arm of Table Rock (10-in size limit), but not at Lake of the Ozarks (15-daily limit). Although mean lengths of harvested white crappies were highly variable, they increased more in reservoirs with minimum-size limits. The greatest increase was in the James River Arm, where the mean length increased from about 7 to 11 in after imposition of the size limit. Even though the harvest shifted to older white crappies at Wappapello, mean lengths of harvested fish did not increase, because growth was slower during years of the 10-daily limit. Most anglers complied with restrictive regulations; the estimated harvest of sublegal fish was always less than 10% of the legal harvest at reservoirs with minimum-size limits, and less than 1% of the anglers kept more than the daily limits at all reservoirs. White crappie populations at Missouri's large reservoirs can benefit from restrictive regulations if the populations contain few age-4 and older fish and have satisfactory growth.

Dynamics of a Black Crappie Population in a Heterogeneous Cooling Reservoir

Abstract Spatial and annual variation in density, growth, and size structure of black crappies Pomoxis nigromaculatus in Lake Wylie, North Carolina-South Carolina, were determined during a 5-year study. Water temperature, turbidity, total phosphorus, and nitrate+nitrite-nitrogen in Lake Wylie varied across zones and years. Significant (P < 0.0001) year or year-class × zone interactions were detected in catch rates, first-year growth, and second-year growth. Significant (P ≤ 0.0002) spatial and year-class effects on first-, second-, and third-year growth were also observed. Black crappies were attracted to the heated effluent of a power plant. First-year growth was correlated (r = 0.55; P < 0.05) with average water temperature during the growing season (April through October). Second- and third-year growth were among the fastest reported in the literature. Second-year growth was faster in areas with higher densities of threadfin shad Dorosoma petenense, which appeared to concentrate in the more nutrient-ri...

Largemouth Bass Influence on Size Structure of Crappie Populations in Small Oklahoma Impoundments

Populations of largemouth bass Micropterus salmoides and crappies Pomoxis spp. were sampled by spring electrofishing and fall trap-netting, respectively, in 11 small impoundments in Oklahoma during 1984. The proportional stock density (PSD) of the crappie populations was inversely related to the largemouth bass PSD and directly related to the density of largemouth bass. Mean lengths of crappies at age 2 were directly related to largemouth bass density. It was postulated that reduction in crappie numbers through predation by largemouth bass is the determining factor in establishing a favorable population structure of crappies in small impoundments. If desirable crappie populations are to be established in small impoundments, however, anglers may have to accept a greater proportion of small largemouth bass.

Effect of Commercial Harvest of Sport Fish on the Black Crappie Population in Lake Okeechobee, Florida

Commercial harvest of black crappie (Pomoxis nigromaculatus), bluegill (Lepomis macrochirus), and redear sunfish (Lepomis microlophus) was conducted in Lake Okeechobee, Florida during 1976-1981. This fishery removed an annual average of 56 and 24% of the estimated standing crop of harvestable-size black crappie and sunfish (bluegill and redear sunfish combined), respectively. Including the sport harvest, the annual exploitation of black crappie was estimated at 65%. This high exploitation rate resulted in significant increases in growth rate and condition factor of black crappie. The results suggested that the commercial harvest of sunfish also improved the growth rate of young black crappie. Fluctuations in the quality of the black crappie sport fishing were related primarily to hydrologic factors, and the population did not show signs of overfishing. Revenue generated by this commercial fishery exceeded $27 million.

Characteristics of a Crappie Population in an Unfished Small Impoundment Containing Northern Pike

Abstract Desirable black crappie (Pomoxis nigromaculatus) and white crappie (Pomoxis annularis) populations were documented in a small impoundment in Colorado. Individuals 250 mm long and longer comprised 21% of the black crappies and 44% of the white crappies 130 mm long and longer. Mean relative weight (Wr) information indicated that crappie were in good condition and growth rates were average. Northern pike (Esox lucius) population estimates for 550-mm long and longer individuals varied from 119 to 217 fish during the 1973-1980 sampling period. Biomass of northern pike 550 mm long and longer was estimated to be 18.4 kg/hectare in 1980. Northern pike predation may help maintain desirable crappie populations in small impoundments.