Abstract

The Missouri River in South Dakota was dammed in the 1950s and 1960s, altering the biotic and abiotic factors that potentially affect native species in the mainstem reservoirs. Little research has been conducted regarding what factors regulate age-0 catch per unit effort (CPUE) of native fish species since the damming occurred. Thus, we examined age-0 CPUE for 13 native fish species in the four Missouri River mainstem reservoirs. We analyzed data from 1995 to 2015 in Lake Oahe, 2002 to 2016 in Lake Sharpe, 1998 to 2008 in Lake Francis Case, and 2000 to 2013 in Lewis and Clark Lake. Not all species were sampled in all reservoirs. We evaluated potential environmental (inflow, gauge height, peak flow, precipitation, air temperature) and biological (CPUE of other native species, nonnative species, and predators) factors that have documented impacts on age-0 native fish. Significant relationships existed between age-0 native fish CPUE and both biotic and abiotic factors in all four reservoirs, but were species- and reservoir-dependent. Age-0 CPUE was either stable or increasing in all species examined in all reservoirs except age-0 Emerald Shiner Notropis atherinoides in Lewis and Clark Lake. Age-0 Emerald Shiner CPUE in Lewis and Clark Lake was most supported by biological models (e.g., total age-0 nonnative and adult White Bass Morone chrysops CPUE), and a positive relationship existed between age-0 Emerald Shiner and both factors. We believe our findings provide valuable insight into successful management of native fish populations.

Introduction

The Missouri River was once a shallow, muddy river dominated by large abundances of native fish. Today it has been segmented into a series of deep, clear-water impoundments, and is dominated by cool and cold-water nonnative fish. Impounded systems are often stocked with nonnative fish to take advantage of recreational fishing opportunities. Once introduced, nonnative species compete with, prey upon, hybridize with, or introduce disease to native populations (see Gozlan et al. 2010 for review). In natural systems, native fish frequently have higher survival compared with nonnative species, with natural environmental stressors such as discharge (Kiernan et al. 2012). However, in altered systems, nonnative fish can survive better than natives, increasing the abundance of nonnative fish and decreasing the abundance of native species (Gido et al. 2013). Changes in biological (i.e., nonnative species introduction) and environmental (i.e., flow regulation due to impoundment) factors can have strong regulatory effects on native fish abundance.

The Missouri River is impounded into four mainstem reservoirs in South Dakota: Lake Oahe, Lake Sharpe, Lake Francis Case, and Lewis and Clark Lake. Impoundment occurred between 1952 and 1963 in order to provide flood control, irrigation, hydropower, and recreation (Erickson et al. 2008). Since impoundment, daily mean flow has increased and flow variability has decreased (Pegg et al. 2003). Further, variability in mean monthly discharge decreased and the magnitude, frequency, and duration of annual high-flow pulses per year has increased postimpoundment (Galat and Lipkin 2000). In addition to environmental factors, biological factors (i.e., species composition) and the balance between native and nonnative species have also been altered postimpoundment.

Native fishes still present in the Missouri River reservoirs in South Dakota include Bigmouth Buffalo Ictiobus cyprinellus, Bluntnose Minnow Pimephales notatus, Fathead Minnow P. promelas, Brassy Minnow Hybognathus hankinsoni, Emerald Shiner Notropis atherinoides, Freshwater Drum Aplodinotus grunniens, Gizzard Shad Dorosoma cepedianum, Goldeye Hiodon alosoides, Johnny Darter Etheostoma nigrum, Red Shiner Cyprinella lutrensis, River Carpsucker Carpiodes carpio, Shorthead Redhorse Moxostoma macrolepidotum, and White Sucker Catostomus commersonii; (Berry and Young 2004). These species evolved to take advantage of submerged vegetation during high Spring flows for successful spawning. As the Missouri River was impounded, submerged vegetation and increased zooplankton abundance resulted in increased in-river detritus, and in turn increased successful reproduction of many species. However, once impounded, open-water, tributary, and gravel–cobble substrate spawners prospered (Benson 1982). Long-term (i.e., late 1960s through the 2000s) trends resulted in primarily nonnative species benefitting from this shift. Age-0 Freshwater Drum catch per unit effort (CPUE) decreased after impoundment of Lewis and Clark Lake in 1956 until 1961, but then increased between 1962 and 1966 (Swedberg 1968). From 1966 to 1972, native fish biomass decreased approximately 67% in Lewis and Clark Lake (Walburg 1976), a trend common to the other Missouri River reservoirs. Goldeye, River Carpsucker, Buffalos (Bigmouth Buffalo and Smallmouth Buffalo Ictiobus bubalus), and Shorthead Redhorse CPUE have all decreased in Lewis and Clark Lake between 1956 and 2001 (Galat et al. 2005).

Significant reductions in age-0 native fish CPUE that have occurred in the Missouri River since damming have resulted in concerns regarding current trends and factors playing a role in age-0 native fish CPUE. Although annual surveys are conducted on the mainstem reservoirs, age-0 native fish CPUE studies are scarce. We 1) describe patterns in age-0 native fish CPUE for the four mainstem Missouri River reservoirs using linear regressions of age-0 CPUE and year, 2) use an information theoretic framework (Akaike's Information Criterion, AIC) to identify the environmental and biological models with support for explaining age-0 CPUE, and 3) provide species-specific management recommendations based off strong biotic and abiotic relationships observed.

Study Site

Lakes Oahe, Sharpe, Francis Case, and Lewis and Clark Lake are the four mainstem reservoirs of the Missouri River in South Dakota (Figure 1, Table 1). Lake Oahe extends from Garrison Dam to Oahe Dam, Lake Sharpe from Oahe Dam to Big Bend Dam, Lake Francis Case from Big Bend Dam to Fort Randall Dam, and Lewis and Clark Lake from Fort Randall Dam to Gavins Point Dam (Table 2). All four mainstem reservoirs contain numerous native fish and introduced nonnative fish species. Nonnative introductions have included all or a mixture of Brown Trout Salmo trutta, Chinook Salmon Oncorhynchus tshawytscha, Lake Herring Coregonus artedi, Lake Whitefish C. clupeaformis, Lake Trout Salvelinus namaycush, Northern Pike Esox lucius, Muskellunge E. masquinongy, Rainbow Trout Oncorhynchus mykiss, Smallmouth Bass Micropterus dolomieu, Largemouth Bass M. salmoides, Walleye Sander vitreus, and Black Crappie Pomoxis nigromaculatus in at least one of each of the South Dakota reservoirs (South Dakota Game, Fish and Parks 2019).

Figure 1.

Sample sites in Lakes Oahe (1995–2015), Sharpe (2002–2016), Francis Case (1998–2008), and Lewis and Clark Lake (2000–2013) for age-0 native fish collected with seines (a seine arc) and gill nets (a star) in South Dakota. Modified from Sorensen and Knecht (2006), Longhenry (2013), Potter et al. (2015) and Greiner et al. (2016).

Figure 1.

Sample sites in Lakes Oahe (1995–2015), Sharpe (2002–2016), Francis Case (1998–2008), and Lewis and Clark Lake (2000–2013) for age-0 native fish collected with seines (a seine arc) and gill nets (a star) in South Dakota. Modified from Sorensen and Knecht (2006), Longhenry (2013), Potter et al. (2015) and Greiner et al. (2016).

Table 1.

Species sampled (Bigmouth Buffalo Ictiobus cyprinellus; Bluntnose Minnow Pimephales notatus; Brassy Minnow Hybognathus hankinsoni; Emerald Shiner Notropis atherinoides; Fathead Minnow P. promelas; Freshwater Drum Aplodinotus grunniens; Gizzard Shad Dorosoma cepedianum; Goldeye Hiodon alosoides; Johnny Darter Etheostoma nigrum; Red Shiner Cyprinella lutrensis; River Carpsucker Carpiodes carpio; Shorthead Redhorse Moxostoma macrolepidotum; White Sucker Catostomus commersonii); denoted with an “X” in Lakes Oahe (1995–2015), Sharpe (2002–2016), Francis Case (1998–2008), and Lewis and Clark Lake (2000–2013) in South Dakota.

Species sampled (Bigmouth Buffalo Ictiobus cyprinellus; Bluntnose Minnow Pimephales notatus; Brassy Minnow Hybognathus hankinsoni; Emerald Shiner Notropis atherinoides; Fathead Minnow P. promelas; Freshwater Drum Aplodinotus grunniens; Gizzard Shad Dorosoma cepedianum; Goldeye Hiodon alosoides; Johnny Darter Etheostoma nigrum; Red Shiner Cyprinella lutrensis; River Carpsucker Carpiodes carpio; Shorthead Redhorse Moxostoma macrolepidotum; White Sucker Catostomus commersonii); denoted with an “X” in Lakes Oahe (1995–2015), Sharpe (2002–2016), Francis Case (1998–2008), and Lewis and Clark Lake (2000–2013) in South Dakota.
Species sampled (Bigmouth Buffalo Ictiobus cyprinellus; Bluntnose Minnow Pimephales notatus; Brassy Minnow Hybognathus hankinsoni; Emerald Shiner Notropis atherinoides; Fathead Minnow P. promelas; Freshwater Drum Aplodinotus grunniens; Gizzard Shad Dorosoma cepedianum; Goldeye Hiodon alosoides; Johnny Darter Etheostoma nigrum; Red Shiner Cyprinella lutrensis; River Carpsucker Carpiodes carpio; Shorthead Redhorse Moxostoma macrolepidotum; White Sucker Catostomus commersonii); denoted with an “X” in Lakes Oahe (1995–2015), Sharpe (2002–2016), Francis Case (1998–2008), and Lewis and Clark Lake (2000–2013) in South Dakota.
Table 2.

Characteristics including upstream dam, downstream dam, year impounded, surface area (km2, km2 = square kilometers), and shoreline length (km, km = kilometers) of the four Missouri River reservoirs (Lakes Oahe, Sharpe, Francis Case, and Lewis and Clark) in South Dakota as of 2020.

Characteristics including upstream dam, downstream dam, year impounded, surface area (km2, km2 = square kilometers), and shoreline length (km, km = kilometers) of the four Missouri River reservoirs (Lakes Oahe, Sharpe, Francis Case, and Lewis and Clark) in South Dakota as of 2020.
Characteristics including upstream dam, downstream dam, year impounded, surface area (km2, km2 = square kilometers), and shoreline length (km, km = kilometers) of the four Missouri River reservoirs (Lakes Oahe, Sharpe, Francis Case, and Lewis and Clark) in South Dakota as of 2020.

Methods

Fish sampling

South Dakota Game, Fish and Parks personnel sampled 13 native species during standard surveys: Bigmouth Buffalo, Bluntnose Minnow, Brassy Minnow, Emerald Shiner, Fathead Minnow, Freshwater Drum, Gizzard Shad, Goldeye, Johnny Darter, Red Shiner, River Carpsucker, Shorthead Redhorse, and White Sucker. Personnel sampled age-0 and adult fish from 1995 to 2015 in Lake Oahe, 2002 to 2016 in Lake Sharpe, 1998 to 2008 in Lake Francis Case, and 2000 to 2013 in Lewis and Clark Lake. Personnel collected age-0 fish on all reservoirs using a 6.4-mm nylon mesh bag seine, measuring 30.5 m long by 2.4 m deep with a 1.8-m by 1.8-m bag during standardized annual population assessments (Lott et al. 1994). Personnel collected age-0 native fish in four seine hauls at nine sampling stations on Lake Oahe, four seine hauls at four stations on Lake Sharpe, and four seine hauls at seven stations on Lake Francis Case. They made six seine hauls at six stations on Lewis and Clark Lake using methods described in Martin et al. (1981) and Hayes et al. (1996). On all reservoirs, personnel used a standard multifilament nylon gill net—91.4 m long by 1.8 m deep with panels of the following bar mesh sizes: 12.7-mm, 19.1-mm, 25.4-mm, 31.8-mm, 38.1-mm, 50.8-mm, and 63.5-mm—to collect adult fish. On Lake Oahe, they set three overnight gill nets for 20 h on the bottom of 0- to 10-m and 10-m to 20-m depth zones (where possible; Potter et al. 2015; Figure 1) at nine locations. On Lake Sharpe, they set six overnight gill nets at ≤9-m depth (three nets) and >9-m depth (three nets) at four locations, where possible (Greiner et al. 2016). On Lake Francis Case, they set six overnight gill nets at the bottom of each depth zone (where possible) and an embayment at four locations. On Lewis and Clark Lake, they set an overnight gill net at 0-m to 12-m depth at six locations, and set an overnight gill net set at 12-m to 24-m depth at six locations (Sorensen and Knecht 2006).

Environmental variables

Personnel obtained precipitation (mean mm/month) and air temperature (mean °C/month) data from the NOAA (National Oceanic and Atmospheric Administration) climate website (NOAA 2018) from 1995 to 2016. Precipitation and air temperature data are collected by NOAA using a method described in Karl and Koss (1984). In brief, South Dakota is divided into nine divisions by NOAA, and the divisional values are weighted by area to compute statewide values (Karl and Koss 1984). Personnel obtained peak flow, inflow, and gauge height data from the USGS (United States Geological Survey) water database website (USGS 2018). For all reservoirs, we used the gauge nearest the upstream dam. We used the gauges at Bismarck, North Dakota, and Pierre, Chamberlain, and Springfield, South Dakota, for Lakes Oahe, Sharpe, Francis Case, and Lewis and Clark, respectively. We took seasonal environmental variables from each month representing the four seasons including Spring (April), Summer (July), Fall (October), and Winter (January) from 1995to 2015 in Lake Oahe, 2002 to 2016 in Lake Sharpe, 1998 to 2008 in Lake Francis Case, and 2000 to 2013 in Lewis and Clark Lake.

Statistical analysis

South Dakota Game, Fish and Parks personnel recorded age-0 and adult native fish catch per unit effort (CPUE) for seine (No./haul) and gill net (No./net night) catches, and we used mean annual CPUE data for each reservoir in the multiple regression models. We loge-transformed (ln[x + 1]) data to meet normality assumptions similar to DeBoer et al. (2013). We assessed temporal and spatial patterns in age-0 CPUE within and among the reservoirs using an analysis of variance, and used multiple regression to evaluate relationships among variables and age-0 native fish CPUE. We used linear regressions of age-0 CPUE versus year to assess trends. We set statistical significance for all analyses at α = 0.10. We performed all analyses in Program R version 3.1.3 (R Core Team 2018).

Model selection

We used multiple linear models to examine the variation observed in age-0 native fish CPUE for each species on each reservoir. We hypothesized three main effects categories to be related to each native fish's CPUE: 1) CPUE of adult nonnative fish as potential predators for age-0 native fish, 2) CPUE of age-0 native and nonnative fish as potential competitors for age-0 native fish, and 3) seasonal abiotic variables that influence production or capture of age-0 native fish. We developed 18 single parameter candidate models to assess these three main categories (Table 3). We then combined logical parameters to create five additional multiparameter candidate models (Table 3). We then used Akaike's Information Criterion corrected for small sample size (AICc; Burnham and Anderson 2002) to determine which model best supported trends in each species' CPUE. We reported the number of estimated parameters (K), second-order AICc, difference in AIC values relative to the best model (ΔAICc), log-likelihood (LL), Akaike weights (Weights), coefficient of determination (r2), and 95% confidence interval of the coefficient of determination (95% CI) for each model. We evaluated models under different time series based on reservoir; 1995–2015 in Lake Oahe; 2002–2016 in Lake Sharpe; 1998–2008 in Lake Francis Case; and 2000–2013 in Lewis and Clark Lake. We assessed variance inflation factors, and removed multicollinear variables until all variance inflation factors <10 (Hair et al. 1995). We assessed normality using a Shapiro–Wilk test (Shapiro and Wilk 1965), and used a Hosmer–Lemeshow goodness-of-fit test to assess model fit (Hosmer and Lemeshow 1980).

Table 3.

Model names and terms for candidate models used to explain age-0 native fish catch per unit effort (CPUE) in Lakes Oahe (1995–2015), Sharpe (2002–2016), Francis Case (1998–2008), and Lewis and Clark Lake (2000–2013) in South Dakota. GIS = Gizzard Shad Dorosoma cepedianum; CCF = Channel Catfish Ictalurus punctatus; SAR = Sauger Sander canadensis; SMB = Smallmouth Bass Micropterus dolomieu; WAE = Walleye Sander vitreus; WHB = White Bass Morone Chrysops; WHC = White Crappie Pomoxis annularis; YEP = Yellow Perch Perca flavescens).

Model names and terms for candidate models used to explain age-0 native fish catch per unit effort (CPUE) in Lakes Oahe (1995–2015), Sharpe (2002–2016), Francis Case (1998–2008), and Lewis and Clark Lake (2000–2013) in South Dakota. GIS = Gizzard Shad Dorosoma cepedianum; CCF = Channel Catfish Ictalurus punctatus; SAR = Sauger Sander canadensis; SMB = Smallmouth Bass Micropterus dolomieu; WAE = Walleye Sander vitreus; WHB = White Bass Morone Chrysops; WHC = White Crappie Pomoxis annularis; YEP = Yellow Perch Perca flavescens).
Model names and terms for candidate models used to explain age-0 native fish catch per unit effort (CPUE) in Lakes Oahe (1995–2015), Sharpe (2002–2016), Francis Case (1998–2008), and Lewis and Clark Lake (2000–2013) in South Dakota. GIS = Gizzard Shad Dorosoma cepedianum; CCF = Channel Catfish Ictalurus punctatus; SAR = Sauger Sander canadensis; SMB = Smallmouth Bass Micropterus dolomieu; WAE = Walleye Sander vitreus; WHB = White Bass Morone Chrysops; WHC = White Crappie Pomoxis annularis; YEP = Yellow Perch Perca flavescens).

Results

Age-0 Gizzard Shad dominated total age-0 fish CPUE in all reservoirs (Figure 2). Bigmouth Buffalo, Bluntnose Minnow, and Shorthead Redhorse only reached CPUE that exceeded 1 fish/net in one of the four reservoirs sampled (Figure 3). Brassy Minnow did not exceed CPUE of 1 fish/net in either reservoir in which they were sampled. All other species sampled exceeded CPUE of 1 fish/net in at least two reservoirs. All species' CPUE was stable or increased over the study period except age-0 Emerald Shiner, which decreased in Lewis and Clark Lake (Table 4).

Figure 2.

Age-0 total native fish CPUE (Catch Per Unit Effort; filled circles, solid line) and age-0 Gizzard Shad Dorosoma cepedianum CPUE (open circles, dotted line) for (A) Lakes Oahe (1995–2015), (B) Sharpe (2002–2016), (C) Francis Case (1998–2008), and (D) Lewis and Clark Lake (2000–2013) in South Dakota.

Figure 2.

Age-0 total native fish CPUE (Catch Per Unit Effort; filled circles, solid line) and age-0 Gizzard Shad Dorosoma cepedianum CPUE (open circles, dotted line) for (A) Lakes Oahe (1995–2015), (B) Sharpe (2002–2016), (C) Francis Case (1998–2008), and (D) Lewis and Clark Lake (2000–2013) in South Dakota.

Figure 3.

Age-0 native fish (Bigmouth Buffalo Ictiobus cyprinellus; Bluntnose Minnow Pimephales notatus; Brassy Minnow Hybognathus hankinsoni; Emerald Shiner Notropis atherinoides; Fathead Minnow P. promelas; Freshwater Drum Aplodinotus grunniens; Goldeye Hiodon alosoides; Johnny Darter Etheostoma nigrum; Red Shiner Cyprinella lutrensis; River Carpsucker Carpiodes carpio; Shorthead Redhorse Moxostoma macrolepidotum; White Sucker Catostomus commersonii) catch per unit effort (CPUE) for Lake Oahe (1995–2015; Δ), Lake Sharpe (2002–2016; +), Lake Francis Case (1998–2008; ▪), and Lewis and Clark Lake (2000–2013; •) in South Dakota.

Figure 3.

Age-0 native fish (Bigmouth Buffalo Ictiobus cyprinellus; Bluntnose Minnow Pimephales notatus; Brassy Minnow Hybognathus hankinsoni; Emerald Shiner Notropis atherinoides; Fathead Minnow P. promelas; Freshwater Drum Aplodinotus grunniens; Goldeye Hiodon alosoides; Johnny Darter Etheostoma nigrum; Red Shiner Cyprinella lutrensis; River Carpsucker Carpiodes carpio; Shorthead Redhorse Moxostoma macrolepidotum; White Sucker Catostomus commersonii) catch per unit effort (CPUE) for Lake Oahe (1995–2015; Δ), Lake Sharpe (2002–2016; +), Lake Francis Case (1998–2008; ▪), and Lewis and Clark Lake (2000–2013; •) in South Dakota.

Table 4.

Summary statistics, including the F-statistic, P-value, and r2 (coefficient of determination) values for linear regressions of species (Bigmouth Buffalo Ictiobus cyprinellus; Bluntnose Minnow Pimephales notatus; Brassy Minnow Hybognathus hankinsoni; Emerald Shiner Notropis atherinoides; Fathead Minnow P. promelas; Freshwater Drum Aplodinotus grunniens; Gizzard Shad Dorosoma cepedianum; Goldeye Hiodon alosoides; Johnny Darter Etheostoma nigrum; Red Shiner Cyprinella lutrensis; River Carpsucker Carpiodes carpio; Shorthead Redhorse Moxostoma macrolepidotum; White Sucker Catostomus commersonii) catch per unit effort (CPUE) versus year in Lakes Oahe (1995–2015), Sharpe (2002–2016), Francis Case (1998–2008), and Lewis and Clark Lake (2000–2013) in South Dakota. For trends, a P-value of <0.05 was deemed significant, and “+” denotes an increasing trend, “±” denotes a stable trend, “—” denotes not applicable, and “−” denotes a decreasing trend.

Summary statistics, including the F-statistic, P-value, and r2 (coefficient of determination) values for linear regressions of species (Bigmouth Buffalo Ictiobus cyprinellus; Bluntnose Minnow Pimephales notatus; Brassy Minnow Hybognathus hankinsoni; Emerald Shiner Notropis atherinoides; Fathead Minnow P. promelas; Freshwater Drum Aplodinotus grunniens; Gizzard Shad Dorosoma cepedianum; Goldeye Hiodon alosoides; Johnny Darter Etheostoma nigrum; Red Shiner Cyprinella lutrensis; River Carpsucker Carpiodes carpio; Shorthead Redhorse Moxostoma macrolepidotum; White Sucker Catostomus commersonii) catch per unit effort (CPUE) versus year in Lakes Oahe (1995–2015), Sharpe (2002–2016), Francis Case (1998–2008), and Lewis and Clark Lake (2000–2013) in South Dakota. For trends, a P-value of <0.05 was deemed significant, and “+” denotes an increasing trend, “±” denotes a stable trend, “—” denotes not applicable, and “−” denotes a decreasing trend.
Summary statistics, including the F-statistic, P-value, and r2 (coefficient of determination) values for linear regressions of species (Bigmouth Buffalo Ictiobus cyprinellus; Bluntnose Minnow Pimephales notatus; Brassy Minnow Hybognathus hankinsoni; Emerald Shiner Notropis atherinoides; Fathead Minnow P. promelas; Freshwater Drum Aplodinotus grunniens; Gizzard Shad Dorosoma cepedianum; Goldeye Hiodon alosoides; Johnny Darter Etheostoma nigrum; Red Shiner Cyprinella lutrensis; River Carpsucker Carpiodes carpio; Shorthead Redhorse Moxostoma macrolepidotum; White Sucker Catostomus commersonii) catch per unit effort (CPUE) versus year in Lakes Oahe (1995–2015), Sharpe (2002–2016), Francis Case (1998–2008), and Lewis and Clark Lake (2000–2013) in South Dakota. For trends, a P-value of <0.05 was deemed significant, and “+” denotes an increasing trend, “±” denotes a stable trend, “—” denotes not applicable, and “−” denotes a decreasing trend.

Environmental models had the greatest support for explaining age-0 Bigmouth Buffalo (Table S1, Supplemental Material) and White Sucker (Table S2, Supplemental Material) CPUE in all reservoirs sampled. April temperature was the model with the greatest support for explaining age-0 Bigmouth Buffalo CPUE in Lake Oahe (Table 5). Top models explaining age-0 White Sucker CPUE included the April environmental model for Lake Oahe, and January temperature in Lake Sharpe (Table 5). Biological models had the greatest support for explaining age-0 Bluntnose Minnow and Red Shiner CPUE in all reservoirs sampled (Table S1 and S2, Supplemental Materials). The top-ranked model explaining age-0 Bluntnose Minnow CPUE was adult Channel Catfish Ictalurus punctatus CPUE (Table 5). The top model explaining age-0 Red Shiner CPUE was age-0 Gizzard Shad CPUE in Lake Francis Case and adult White Bass CPUE in Lewis and Clark Lake (Table 5).

Table 5.

Model selection results from 28 candidate models predicting age-0 native fish (Bigmouth Buffalo Ictiobus cyprinellus; Bluntnose Minnow Pimephales notatus; Brassy Minnow Hybognathus hankinsoni; Emerald Shiner Notropis atherinoides; Fathead Minnow P. promelas; Freshwater Drum Aplodinotus grunniens; Gizzard Shad Dorosoma cepedianum; Goldeye Hiodon alosoides; Johnny Darter Etheostoma nigrum; Red Shiner Cyprinella lutrensis; River Carpsucker Carpiodes carpio; Shorthead Redhorse Moxostoma macrolepidotum; White Sucker Catostomus commersonii) catch per unit effort (CPUE) in Lakes Oahe (1995–2015), Sharpe (2002–2016), Francis Case (1998–2008), and Lewis and Clark Lake (2000–2013) in South Dakota. Included are the top models in the analyses with the number of estimated parameters (K), second-order Akaike's Information Criterion (AICc), Akaike weights (Weights), coefficient of determination (r2), trend (− or +), and 95% confidence interval of the coefficient of determination (95% CI). Model parameter descriptions can be found in Table 3.

Model selection results from 28 candidate models predicting age-0 native fish (Bigmouth Buffalo Ictiobus cyprinellus; Bluntnose Minnow Pimephales notatus; Brassy Minnow Hybognathus hankinsoni; Emerald Shiner Notropis atherinoides; Fathead Minnow P. promelas; Freshwater Drum Aplodinotus grunniens; Gizzard Shad Dorosoma cepedianum; Goldeye Hiodon alosoides; Johnny Darter Etheostoma nigrum; Red Shiner Cyprinella lutrensis; River Carpsucker Carpiodes carpio; Shorthead Redhorse Moxostoma macrolepidotum; White Sucker Catostomus commersonii) catch per unit effort (CPUE) in Lakes Oahe (1995–2015), Sharpe (2002–2016), Francis Case (1998–2008), and Lewis and Clark Lake (2000–2013) in South Dakota. Included are the top models in the analyses with the number of estimated parameters (K), second-order Akaike's Information Criterion (AICc), Akaike weights (Weights), coefficient of determination (r2), trend (− or +), and 95% confidence interval of the coefficient of determination (95% CI). Model parameter descriptions can be found in Table 3.
Model selection results from 28 candidate models predicting age-0 native fish (Bigmouth Buffalo Ictiobus cyprinellus; Bluntnose Minnow Pimephales notatus; Brassy Minnow Hybognathus hankinsoni; Emerald Shiner Notropis atherinoides; Fathead Minnow P. promelas; Freshwater Drum Aplodinotus grunniens; Gizzard Shad Dorosoma cepedianum; Goldeye Hiodon alosoides; Johnny Darter Etheostoma nigrum; Red Shiner Cyprinella lutrensis; River Carpsucker Carpiodes carpio; Shorthead Redhorse Moxostoma macrolepidotum; White Sucker Catostomus commersonii) catch per unit effort (CPUE) in Lakes Oahe (1995–2015), Sharpe (2002–2016), Francis Case (1998–2008), and Lewis and Clark Lake (2000–2013) in South Dakota. Included are the top models in the analyses with the number of estimated parameters (K), second-order Akaike's Information Criterion (AICc), Akaike weights (Weights), coefficient of determination (r2), trend (− or +), and 95% confidence interval of the coefficient of determination (95% CI). Model parameter descriptions can be found in Table 3.

For most species, whether environmental or biological models had the greatest support was reservoir-dependent. Top models explaining age-0 Brassy Minnow CPUE included adult Smallmouth Bass CPUE in Lake Oahe and January temperature in Lake Sharpe (Table 5). Top models explaining age-0 Emerald Shiner CPUE included environmental factors in Lakes Oahe (i.e., October gauge height) and Sharpe (i.e., April temperature), and biological factors in Lakes Francis Case (i.e., adult walleye CPUE) and Lewis and Clark (i.e., total age-0 nonnative CPUE; Table 5). Top-ranked models explaining age-0 Gizzard Shad CPUE included adult Channel Catfish CPUE in Lakes Oahe and Lake Francis Case, July gauge height in Lake Sharpe, and July temperature in Lewis and Clark Lake (Table 5). The top model explaining age-0 Shorthead Redhorse CPUE was total nonnative age-0 CPUE in Lake Francis Case, and July gauge height in Lewis and Clark Lake (Table 5).

For age-0 Fathead Minnow and Goldeye, environmental models had the greatest support for explaining CPUE in most reservoirs sampled. Top models explaining age-0 Fathead Minnow CPUE included adult Smallmouth Bass CPUE in Lake Oahe, January precipitation in Lake Sharpe, and total age-0 nonnative CPUE in Lake Francis Case (Table 5). Models with the greatest support for explaining age-0 Goldeye CPUE included January precipitation in Lake Oahe, July gauge height in Lake Sharpe, and adult White Bass CPUE in Lake Francis Case. For other species, biological models had the greatest support for explaining species CPUE.

Biological models had the greatest support for explaining age-0 Freshwater Drum, Johnny Darter, and River Carpsucker CPUE in most reservoirs sampled. The model with the most support in explaining Freshwater Drum CPUE was age-0 Gizzard Shad CPUE in Lake Oahe, age-0 nonnative CPUE in Lakes Sharpe and Francis Case, and July gauge height in Lewis and Clark Lake (Table 5). Top models explaining age-0 Johnny Darter CPUE included biological factors (i.e., adult Smallmouth Bass CPUE in Lake Oahe, adult Channel Catfish CPUE in Lakes Sharpe and Francis Case), except for Lewis and Clark Lake (i.e., April precipitation; Table 5). The top model explaining age-0 River Carpsucker CPUE was April gauge height in Lake Oahe (Table 5). Models including biological factors had the most support for explaining age-0 River Carpsucker in all other reservoirs sampled, including adult Channel Catfish CPUE, adult Walleye CPUE, and age-0 Gizzard Shad CPUE.

Discussion

This study identified environmental and biological factors affecting trends of age-0 native fish CPUE in impounded mainstem reservoirs of the Missouri River. We found relationships between seasonal flows and age-0 CPUE for all of our study species, implying that management of such flows is a multispecies approach to increasing native fish abundance. Further, seasonal temperature variation was related to age-0 CPUE for 11 of our study species, suggesting that modification of the thermal regime is a prudent management approach to bolster abundance of these age-0 native fish species. Relationships between total age-0 nonnative CPUE and age-0 native fish CPUE existed for 11 species as well, so removal of age-0 nonnative species may benefit age-0 native fish species. Relationships between adult predators (i.e., Channel Catfish, Smallmouth Bass, Walleye, White Bass) and age-0 native fish CPUE existed for 11 species, indicating that management of adult predatory species is a tool to manage many native fish species simultaneously. Age-0 Gizzard Shad abundance was related to nine species, suggesting that management focused on increasing or sustaining current abundances of the species will benefit the entire fish assemblage, both native and nonnative.

Schlosser (1985) found strong relationships among environmental and biological variables and age-0 native fish CPUE, as did we. Factors that affected age-0 native fish CPUE varied by species and reservoir. Each Missouri River reservoir has unique physical and chemical characteristics. Recognizing this, much of the research examining factors related to age-0 CPUE in the four Missouri River reservoirs of South Dakota has used a reservoir scale instead of a system scale (Beck et al. 1997, Graeb et al. 2010). By running our analyses separately for each reservoir, we revealed reservoir-specific CPUE trends and relationships, allowing for reservoir-scale management recommendations for each species.

Decreasing the magnitude of seasonal Spring (i.e., April) flows may increase age-0 CPUE of Bigmouth Buffalo, Brassy Minnow, Goldeye, River Carpsucker, and White Sucker in Lake Oahe; Brassy Minnow, Bluntnose Minnow, Freshwater Drum, Goldeye, and River Carpsucker in Lake Sharpe; and Emerald Shiner and Freshwater Drum in Lewis and Clark Lake. However, decreasing the magnitude of Spring flows may decrease age-0 CPUE of Fathead Minnow in Lake Sharpe, and Johnny Darter in Lewis and Clark Lake. Markle and Dunsmoor (2007) found that on Upper Klamath Lake, Oregon Fathead Minnow CPUE was negatively correlated with lake elevation. Johnny Darter are abundant in the Lewis and Clark Lake delta, which likely relies on peak Spring flows for maintained connectivity; therefore, maintaining Spring flows in Lewis and Clark Lake may benefit the species. Brassy Minnow are of Level-4 concern in South Dakota (Hoagstrom et al. 2006), and were caught in the lowest numbers in the fewest reservoirs, so decreasing flows on both Lakes Oahe and Sharpe to benefit the species is a priority. Emerald Shiner prefer moderate water velocities (Galat et al. 2005), so may benefit from decreased flows. Freshwater Drum benefit from decreased flows, as do Bigmouth Buffalo (Shoup and Wahl 2009).

However, management decreasing Spring flows to benefit species such as Emerald Shiner and Bigmouth Buffalo may decrease growth rates of Freshwater Drum and CPUE of River Carpsucker. Rutherford et al. (1995) found that on the lower Mississippi River age-0 Freshwater Drum growth was negatively correlated with discharge, so it is plausible that the timing of high discharge (and subsequent increase in gauge height) determines the effect of the variable on age-0 Freshwater Drum growth and CPUE. However, Jacquemin et al. (2015) found magnitude of flow, and not timing, to be related to Freshwater Drum growth rates. Still again, Richard and Rypel (2013) found that on five rivers throughout Georgia, Alabama, and Mississippi, Freshwater Drum growth was correlated to the annual number of days of maximum flow (i.e., duration of peak flow). Peterson and Jennings (2007) found a correlation between the number of days river discharge exceeds 85 m3s−1 and age-0 River Carpsucker CPUE.

Decreasing Summer flows may increase age-0 abundances of Goldeye and River Carpsucker in Lake Oahe; Bluntnose Minnow, Gizzard Shad, and Goldeye in Lake Sharpe; Gizzard Shad in Lake Francis Case; and Emerald Shiner and Freshwater Drum in Lewis and Clark Lake. However, decreasing Summer flows may decrease age-0 Shorthead Redhorse in Lewis and Clark Lake. To continue to sustain or increase the low CPUE of age-0 Shorthead Redhorse in Lewis and Clark Lake, July gauge height must remain high. Droughts in the early 2000s coincide with the lowest CPUE of age-0 Shorthead Redhorse in the reservoir. Emerald Shiner and Freshwater Drum are abundant in Lewis and Clark, so management prioritized to benefit Shorthead Redhorse is prudent in the reservoir.

Modification of environmental factors such as the thermal regime may also increase age-0 native fish CPUE. Decreasing Spring cold-water releases may increase age-0 CPUE of Bigmouth Buffalo and White Sucker in Lake Oahe, Johnny Darter in Lake Sharpe, Fathead Minnow and Freshwater Drum in Lake Francis Case, and Gizzard Shad and Shorthead Redhorse in Lewis and Clark Lake. Braaten and Guy (2004) found that in the lower channelized Missouri River winter severity in water temperatures (i.e., low temperatures) negatively affected age-0 Freshwater Drum survival. However, decreasing Spring cold-water releases may decrease age-0 CPUE of Fathead Minnow in Lake Oahe; Emerald Shiner in Lake Sharpe; Emerald Shiner, Goldeye, Johnny Darter, and River Carpsucker in Lake Francis Case; and Johnny Darter and River Carpsucker in Lewis and Clark Lake. June–August water temperatures were positively correlated with strong year classes of age-0 Freshwater Drum soon after impoundment of Lewis and Clark Lake (Swedberg and Walburg 1970). Age-0 Goldeye CPUE is positively related to the number of days >15°C between May and July in Alberta, Canada (Donald 1997). We found age-0 River Carpsucker CPUE to be related to January or April air temperature, whereas Braaten and Guy (1999) found that adult River Carpsucker CPUE was positively related with mean March and June–July water temperatures in tributaries. We found little evidence of previously documented positive relationships between temperature and age-0 Freshwater Drum CPUE (Edsall 1967; Ostazèski and Spangler 2001).

Regulating biological factors such as decreasing adult sport fish CPUE may further increase age-0 native fish CPUE. Decreasing adult Channel Catfish CPUE may increase age-0 CPUE of Johnny Darter in Lake Oahe; Bluntnose Minnow, Goldeye, and Johnny Darter in Lake Sharpe; Goldeye, Johnny Darter, and River Carpsucker in Lake Francis Case; and Johnny Darter in Lewis and Clark Lake. However, decreasing adult channel catfish CPUE may decrease age-0 CPUE of Gizzard Shad, Goldeye, and River Carpsucker in Lake Oahe; Emerald Shiner in Lake Sharpe; Gizzard Shad and Red Shiner in Lake Francis Case; and Freshwater Drum and Gizzard Shad in Lewis and Clark Lake. Decreasing adult Smallmouth Bass CPUE may increase age-0 CPUE of Freshwater Drum in Lake Oahe, Fathead Minnow in Lake Sharpe, and Fathead Minnow and Freshwater Drum in Lake Francis Case. Smallmouth Bass numbers have been increasing in three of the four South Dakota Missouri River reservoirs since the mid-1980s (Fincel et al. 2019), concurrent with observed Brassy Minnow declines. Decreasing adult Smallmouth Bass CPUE may decrease Brassy Minnow, Fathead Minnow, and Johnny Darter in Lake Oahe; Bluntnose Minnow and Freshwater Drum in Lake Sharpe; and River Carpsucker in Lake Francis Case. Smallmouth Bass prey on Fathead Minnow to the point of extirpation from littoral zones in small Ontario lakes (MacRae and Jackson 2001), but we found that size and environmental complexity of Lake Oahe possibly confounds this relationship. Decreasing adult Walleye abundance may increase age-0 CPUE of Johnny Darter in Lake Sharpe; Freshwater Drum, Gizzard Shad, and Johnny Darter in Lake Francis Case; and River Carpsucker in Lewis and Clark Lake. Johnny Darters composed a small proportion of Walleye diets in Okobojo Bay, Lake Oahe (Jackson et al. 1992). Emerald Shiners are prey for Walleye in Lake Oahe (Bryan et al. 1995). Hartman and Margraf (1992) found that Walleye in Lake Erie consume prey fish in proportion to their abundance, supporting our findings that biological factors dictate age-0 Emerald Shiner CPUE. Decreasing adult Walleye abundance may decrease age-0 CPUE of Fathead Minnow and River Carpsucker in Lake Sharpe, Emerald Shiner and Fathead Minnow in Lake Francis Case, and Gizzard Shad in Lewis and Clark Lake. Decreasing adult White Bass CPUE may increase age-0 CPUE of Brassy Minnow in Lake Oahe; Bluntnose Minnow, Freshwater Drum, River Carpsucker, and White Sucker in Lake Sharpe; Emerald Shiner, Fathead Minnow, River Carpsucker, and Red Shiner in Lake Francis Case; and Emerald Shiner in Lewis and Clark Lake. However, decreasing adult White Bass CPUE may decrease age-0 CPUE of Goldeye in Lake Francis Case, and Freshwater Drum and Red Shiner in Lewis and Clark Lake. Age-0 River Carpsucker CPUE spiked in 2006 in Lake Oahe, concurrent with a 2006 Columnaris disease outbreak that significantly decreased the White Bass population in the reservoir (Radigan and Fincel 2019).

Removal of age-0 nonnative species may increase age-0 CPUE of Freshwater Drum and Johnny Darter in Lake Oahe; Brassy Minnow in Lake Sharpe; Fathead Minnow, Freshwater Drum, and Goldeye in Lake Francis Case; and Shorthead Redhorse in Lewis and Clark Lake. Age-0 Freshwater Drum outcompete age-0 sport fish for zooplankton (Sullivan et al. 2012). MacRae and Jackson (2001) found that age-0 White Sucker coexisted with Smallmouth Bass, with no apparent significant relationship between the two species. Decreasing age-0 nonnative species may decrease age-0 CPUE of Bigmouth Buffalo in Lake Oahe; Emerald Shiner, Freshwater Drum, Johnny Darter, and White Sucker in Lake Sharpe; Gizzard Shad, Johnny Darter, Red Shiner, and Shorthead Redhorse in Lake Francis Case; and Emerald Shiner in Lewis and Clark Lake. Pflieger (1997) documented Bighead Carp Hypophthalmichthys nobilis competition with Bigmouth Buffalo, yet we found positive relationships between age-0 Bigmouth Buffalo CPUE and total nonnative age-0 CPUE. A large number of species may be affected both positively and negatively by removing age-0 nonnative species; therefore, it is necessary for management to consider whether an increase in CPUE of a suite of species is worth the concurrent decrease in CPUE of another suite of species.

Although both environmental and biological factors can be used to manage native fish CPUE, we suggest that management of native species is prioritized by addressing the species caught in the lowest CPUE in the fewest reservoirs first. Management focused on Brassy Minnow and Bluntnose Minnow is a priority because of their low abundances and limited distributions. It is plausible that environmental factors are compounding biological causes of decreases of Brassy Minnow CPUE throughout South Dakota. Presumed reasons for Brassy Minnow declines are reduction in aquatic vegetation, increased water temperature, and increased turbidity due to human impacts (Cross and Moss 1987). Shoreline degradation and loss of diverse littoral habitat are characteristic of the Missouri River reservoirs following impoundment (Miranda 2017). We only sampled Bluntnose Minnow in Lake Sharpe, probably because of its abundance of quiet backwaters, preferred habitat for the species (Galat et al. 2005). Other Missouri River reservoirs with abundant floodplain habitat (i.e., Lewis and Clark Lake) may be feasible stocking areas for Bluntnose Minnow. Feyrer et al. (2006) found 81% of variance in annual production of age-0 Splittail Pogonichthys macrolepidotus in Yolo County, California was explained by inundated floodplain habitat during January–June.

After addressing the species caught in the lowest CPUE in the fewest reservoirs first, species absent from sampling or sampled intermittently or in low abundances in some of the reservoirs in their range distribution are the next highest priority for management. Shorthead Redhorse and Bigmouth Buffalo management in Lake Francis Case takes priority over other reservoirs because of the lower CPUE and frequency of presence in that reservoir. Galat et al. (2005) found that Shorthead Redhorse CPUE was decreasing from 1956 to 2001, whereas we found age-0 Shorthead Redhorse CPUE (albeit low) was increasing from 2002 to 2013. Red Shiner were sampled in abundance in both Lake Francis Case and Lewis and Clark Lake, so management may focus on reintroducing this species into the northern reaches of the Missouri River in South Dakota. Donald (1997) found that dominant year-classes occur in age-0 Goldeye once every 3 y, whereas we found no dominant year classes in our study system. Further, no Goldeye were sampled in Lewis and Clark Lake, which may allow for stocking of the species in that reservoir to increase the Goldeye's range.

Creation of floodplain habitats in the Missouri River reservoirs may bolster age-0 native fish CPUE. Johnny Darter are five times more numerous in the Lewis and Clark Lake delta than in the main channel (Kaemingk et al. 2007), which may be the reason this reservoir was the only one where environmental models showed the most support for explaining age-0 Johnny Darter CPUE. All other reservoirs lack deltas, so lower abundances of Johnny Darters likely result in predation being a greater factor than in Lewis and Clark Lake. Prior research has suggested that Johnny Darter may prefer reservoir habitats to turbid river habitats (Hendrickson and Power 1999). Galat et al. (2005) found River Carpsucker CPUE to be decreasing in Lewis and Clark Lake from 1956 to 2001. We found age-0 River Carpsucker CPUE to be stable (but low) between 2002 and 2013. Age-0 River Carpsucker have been found to frequent slow to moderate water velocities in channelized reaches of the Missouri River (Galat et al. 2005), and Lewis and Clark Lake flows into the channelized Missouri River at Sioux City, Iowa. Low densities of age-0 River Carpsucker in Lewis and Clark Lake may be sustained by fish successfully recruiting to adulthood in the channelized reach. Higher densities of age-0 River Carpsucker in the other reservoirs may be sustained by ensuring that existing biological and environmental conditions are preserved.

Environmental changes (i.e., sedimentation) in the past 20 y may have become less conducive for species, requiring habitat restoration. Galat et al. (2005) found Freshwater Drum CPUE to be increasing in Lewis and Clark Lake from 1956 to 2001, and we found age-0 Freshwater Drum CPUE to be stable between 2002 and 2013. Rypel et al. (2006) found that among Alabama reservoirs, lotic environments and reservoirs with short retention time were the most favorable for robust and fast-growing Freshwater Drum production. However, Lewis and Clark Lake has a short retention time (Galat et al. 2005), and yet does not feature robust Freshwater Drum production. Emerald Shiner CPUE increased in the Missouri River postimpoundment, presumably because of reduced turbidity in the main channel (Pflieger and Grace 1987). Emerald Shiner CPUE was decreasing in the Lewis and Clark Lake over our study period, so other factors may be affecting the population at a greater magnitude than reduced turbidity or else turbidity levels may have returned to pre-impoundment levels.

Gizzard Shad are found in high CPUE in Lake Sharpe, and these levels of CPUE will likely maintain regardless of predation due to high fecundity and available thermal refuge in the side-channel embayments. Galat et al. (2005) found Gizzard Shad CPUE to be increasing in Lewis and Clark Lake from 1956 to 2001, yet we found age-0 Gizzard Shad CPUE to be stable between 2002 and 2013. South Dakota Game, Fish and Parks began stocking Lake Oahe with adult prespawn Gizzard Shad in 2013 (Fincel et al. 2017). Gizzard Shad CPUE was stable over our study period, despite improvement efforts. Gizzard Shad are a primary forage base for nonnative predators in Lake Oahe (Wuellner et al. 2010; Fincel et al. 2014, 2016), and we found relationships between age-0 Gizzard Shad and adult predators in all reservoirs. In Lake Oahe, severe winters in 2009–2011 reduced the Gizzard Shad population in Lake Oahe to levels undetectable using methods employed for annual surveys (Fincel et al. 2013, 2017). Overwinter mortality is likely continuing to suppress the Gizzard Shad population in Lake Oahe; and with decreased CPUE, predation is likely keeping Gizzard Shad CPUE low.

Species that are ubiquitous throughout their entire range distribution need the least prioritization for management. White Sucker likely need minimal management because of their ubiquity throughout South Dakota. Species such as age-0 Fathead Minnow CPUE may benefit from management focused on other species, such as restoration of floodplain habitats. Age-0 Fathead Minnow CPUE was highest in a flood year, likely as a result of inundation of the floodplain and resulting proliferation of backwater habitats. This is corroborated by Haines and Tyus (1990) that found Fathead Minnows favored ephemeral backwater habitat on the Green River in Utah. However, it is likely that hundreds of thousands of Fathead Minnows are dumped into the Missouri River reservoirs each year by Walleye anglers discarding excess bait, which may be masking any of the potential relationships we sought to identify.

Management Implications

An understanding of the factors that influence age-0 native fish CPUE allows for effective goal-oriented management. Management to maximize native fish populations includes mimicking the natural flow regime and altering the habitat of today to reflect the habitats that were present in the four Missouri River mainstem reservoirs prior to impoundment. Large-scale flow experiments have informed management regarding improving water quality, habitat restoration, and native biodiversity restoration (Olden et al. 2014). Flood-level spring flows mimicking historical flood flows likely benefit native species like Fathead Minnow (Poff et al. 1997).

We believe restoring a natural flow regime by increasing flow variability and simulating peak seasonal flows may benefit native species in the four mainstem Missouri River reservoirs in South Dakota as well. Shoreline degradation and loss of diverse littoral habitat are characteristic of the Missouri River reservoirs following impoundment (Miranda 2017), and flow alterations from anthropogenic changes have resulted in negative effects on Brassy Minnow recruitment in small Great Plains streams in eastern Colorado (Falke et al. 2010). Kaemingk et al. (2007) found Red Shiners primarily utilize flowing waters, and Braaten (1983) found that Red Shiner reduce the variability in habitats they use during low flow. Martin et al. (1981) recommend one high-water year every three years to foster inundation of the floodplain vegetation and bolster zooplankton CPUE. However, such management may conflict with current management practices focused on maximizing nonnative fishing opportunities and the other authorized purposes of the Missouri River. As such, implementation of adaptive management approaches focused on benefitting (and not maximizing) both native and nonnative fish species is necessary. Management focused on increasing age-0 native fish species CPUE, with equal weight given to not decreasing age-0 sport fish species CPUE is economically and ecologically provident. Continued monitoring of population trends for native species will ensure declines are documented and addressed. Future research is necessary to investigate the mechanisms involved in the relationships we identified among native fish species and environmental and biological factors. Management implications of our findings are relevant to impounded riverine systems throughout the Midwest.

Supplemental Material

Please note: The Journal of Fish and Wildlife Management is not responsible for the content or functionality of any supplemental material. Queries should be directed to the corresponding author for the article.

Data S1. Age-0 native fish (Bigmouth Buffalo Ictiobus cyprinellus; Bluntnose Minnow Pimephales notatus; Brassy Minnow Hybognathus hankinsoni; Emerald Shiner Notropis atherinoides; Fathead Minnow P. promelas; Freshwater Drum Aplodinotus grunniens; Gizzard Shad Dorosoma cepedianum; Goldeye Hiodon alosoides; Johnny Darter Etheostoma nigrum; Red Shiner Cyprinella lutrensis; River Carpsucker Carpiodes carpio; Shorthead Redhorse Moxostoma macrolepidotum; White Sucker Catostomus commersonii) catch per unit effort (CPUE) in Lakes Oahe (1995–2015), Sharpe (2002–2016), Francis Case (1998–2008), and Lewis and Clark Lake (2000–2013) in South Dakota.

Found at DOI: https://doi.org/10.3996/102019-JFWM-094.S1 (14 KB XLSX).

Table S1. Model selection results from 28 candidate models predicting age-0 native fish catch per unit effort (CPUE) in Lake Oahe, South Dakota, USA, from 1995 through 2015. Included are the top five models in the analyses with the number of estimated parameters (K), second-order Akaike's Information Criterion (AICc), difference in AIC values relative to the best model (ΔAICc), log-likelihood (LL), Akaike weights (Weights), coefficient of determination (r2), and 95% confidence interval of the coefficient of determination (95% CI), and trend (− or +). Model parameter descriptions can be found in Table 1.

Found at DOI: https://doi.org/10.3996/102019-JFWM-094.S2 (34 KB DOCX).

Table S2. Model selection results from 28 candidate models predicting age-0 native fish catch per unit effort (CPUE) in Lake Sharpe, South Dakota, USA, from 2002 through 2016. Included are the top five models in the analyses with the number of estimated parameters (K), second-order Akaike's Information Criterion (AICc), difference in AIC values relative to the best model (ΔAICc), log-likelihood (LL), Akaike weights (Weights), coefficient of determination (r2), and 95% confidence interval of the coefficient of determination (95% CI), and trend (− or +). Model parameter descriptions can be found in Table 1.

Found at DOI: https://doi.org/10.3996/102019-JFWM-094.S3 (34 KB DOCX).

Table S3. Model selection results from 28 candidate models predicting age-0 native fish catch per unit effort (CPUE) in Lake Francis Case, South Dakota, USA, from 1998 through 2008. Included are the top five models in the analyses with the number of estimated parameters (K), second-order Akaike's Information Criterion (AICc), difference in AIC values relative to the best model (ΔAICc), log-likelihood (LL), Akaike weights (Weights), coefficient of determination (r2), and 95% confidence interval of the coefficient of determination (95% CI), and trend (− or +). Model parameter descriptions can be found in Table 1.

Found at DOI: https://doi.org/10.3996/102019-JFWM-094.S4 (32 KB DOCX).

Table S4. Model selection results from 28 candidate models predicting age-0 native fish catch per unit effort (CPUE) in Lewis and Clark Lake, South Dakota, USA, from 1998 through 2008. Included are the top five models in the analyses with the number of estimated parameters (K), second-order Akaike's Information Criterion (AICc), difference in AIC values relative to the best model (ΔAICc), log-likelihood (LL), Akaike weights (Weights), coefficient of determination (r2), and 95% confidence interval of the coefficient of determination (95% CI), and trend (− or +). Model parameter descriptions can be found in Table 1.

Found at DOI: https://doi.org/10.3996/102019-JFWM-094.S5 (30 KB DOCX).

Reference S1.Greiner MJ, Hanten R, Fincel MJ, Meyer H, Potter K, Smith M. 2016. Annual fish population and angler use, harvest and preference surveys on Lake Sharpe, South Dakota, 2016. Pierre: South Dakota Department of Game, Fish and Parks, Wildlife Division. Annual Report 17-03.

Found at DOI: https://doi.org/10.3996/102019-JFWM-094.S6 (898 KB PDF).

Reference S2.Karl T, Koss WJ. 1984. Regional and national monthly, seasonal, and annual temperature weighted by area, 1895–1983. National Ocean and Atmospheric Administration. Historical Climatology Series 4-3.

Found at DOI: https://doi.org/10.3996/102019-JFWM-094.S7 (34.21 MB PDF); also available at https://repository.library.noaa.gov/view/noaa/10238.

Reference S3.Longhenry C. 2013. Annual fish population and angler use and sportfish harvest surveys of Lewis and Clark Lake, South Dakota, 2013. South Dakota Department of Game, Fish and Parks, Wildlife Division. Annual Report 15-03.

Found at DOI: https://doi.org/10.3996/102019-JFWM-094.S8 (680 KB PDF); also available at https://gfp.sd.gov/UserDocs/nav/2013LewisClarkAnnualFishPop.pdf.

Reference S4.Lott J, Fielder D, Johnson B, Riis J, Stone C, Wickstrom G. 1994. Annual fish population surveys on South Dakota Missouri River reservoirs, 1993. Pierre: South Dakota Department of Game, Fish and Parks, Wildlife Division. Annual Report 94-8.

Found at DOI: https://doi.org/10.3996/102019-JFWM-094.S9 (3.72 MB PDF).

Reference S5.[NOAA] National Oceanic and Atmospheric Administration National Centers for Environmental Information. 2018. Climate at a glance: statewide mapping.

Found at DOI: https://doi.org/10.3996/102019-JFWM-094.S10 (78 KB PDF); also available at https://www.ncdc.noaa.gov/cag/.

Reference S6.Potter K, Meyer H, Hanten R, Greiner M, Fincel M, Smith M. 2015. Annual fish population and angler use, harvest and preference surveys on Lake Oahe, South Dakota, 2015. Pierre: South Dakota Department of Game, Fish and Parks, Wildlife Division, Annual Report 16-03.

Found at DOI: https://doi.org/10.3996/102019-JFWM-094.S11 (1.42 MB PDF).

Reference S7.Radigan WJ, Fincel MJ. 2019. Factors affecting White Bass abundance in two Missouri River reservoirs. The Prairie Naturalist 51:3–16.

Found at DOI: https://doi.org/10.3996/102019-JFWM-094.S12 (1.17 MB PDF); also available at https://www.researchgate.net/publication/333747427_Factors_Affecting_White_Bass_Abundance_in_Two_Missouri_River_Reservoirs.

Reference S8.Sorensen J, Knecht G. 2006. Annual fish population and angler use and non-native fish harvest surveys on Lake Francis Case, South Dakota, 2004. Pierre: South Dakota Department of Game, Fish and Parks, Fisheries Division. Report 06-20.

Found at DOI: https://doi.org/10.3996/102019-JFWM-094.S13 (1.21 MB PDF).

Reference S9.South Dakota Game, Fish and Parks. 2019. Fisheries and aquatic resources adaptive management system. 2019–2023 Missouri River Fisheries Management Area. South Dakota Game, Fish and Parks Wildlife Division. Northeast Fisheries Management Area Strategic Plan.

Found at DOI: https://doi.org/10.3996/102019-JFWM-094.S14 (1.64 MB PDF).

Reference S10.[USGS] United States Geological Survey National Water Information System: Web Interface. 2018. Site inventory for the nation.

Found at DOI: https://doi.org/10.3996/102019-JFWM-094.S15 (222 KB PDF); also available at https://waterdata.usgs.gov/nwis/inventory.

Reference S11.Walburg CH. 1976. Changes in the fish populations of Lewis and Clark Lake, 1956–1974, and their relation to water management and the environment. Yankton, South Dakota: U.S. Fish and Wildlife Service. Research Report 79.

Found at DOI: https://doi.org/10.3996/102019-JFWM-094.S16 (2.27 MB PDF); also available at https://books.google.com/books?hl=en&lr=&id=J1gKTA1l_XsC&oi=fnd&pg=PP6&dq=Changes+in+the+fish+populations+of+Lewis+and+Clark+Lake,+1956-1974,+and+their+relation+to+water+management+and+the+environment&ots=o_C6lV4DVF&sig=ITVS8ZfyGAn09HL92Xa_Nm8su6k#v=onepage&q&f=false.

Acknowledgments

We thank all South Dakota Department of Game, Fish and Parks personnel who aided in collection and analysis of data used in this study. Our appreciation is further extended to the Associate Editor and two reviewers for their suggestions that led to improvements of this survey. This research was funded by the Federal Aid in Sport Fish Restoration Program administered through the South Dakota Department of Game, Fish and Parks.

Any use of trade, product, website, or firm names in this publication are for descriptive purposes only and does not imply endorsement by the U.S. Government.

References

References
Beck
HD,
Willis
DW,
Unkenholz
DG,
Stone
CC.
1997
.
Relations between environmental variables and age-0 White Bass abundance in four Missouri River Reservoirs
.
Journal of Freshwater Ecology
12
:
567
575
.
Benson
NG.
1982
.
Some observations on the ecology and fish management of reservoirs in the United States
.
Canadian Water Resources Journal
7
:
2
25
.
Berry
CR
Jr,
Young
B.
2004
.
Fishes of the Missouri National Recreational River, South Dakota and Nebraska
.
Great Plains Research
14
:
89
114
.
Braaten
PJ.
1983
.
The influence of habitat structure and environmental variability on habitat use by fish in the Vermillion River, South Dakota. Master's thesis
.
Brookings
:
South Dakota State University
.
Available: https://openprairie.sdstate.edu/etd/302/ (December 2020).
Braaten
PJ,
Guy
CS.
1999
.
Relations between physicochemical factors and abundance of fishes in tributary confluences of the lower channelized Missouri River
.
Transactions of the American Fisheries Society
128
:
1213
1221
.
Braaten
PJ,
Guy
CS.
2004
.
First-year growth, condition, and size-selective winter mortality of Freshwater Drum in the lower Missouri River
.
Transactions of the American Fisheries Society
133
:
385
393
.
Bryan
SD,
Hill
TD,
Lynott
ST,
Duffy
WG.
1995
.
The influence of changing water levels and temperatures on the food habits of Walleye in Lake Oahe, South Dakota
.
Journal of Freshwater Ecology
10
:
1
10
.
Burnham
KP,
Anderson
DR,
editors.
2002
.
Model selection and multimodel inference, a practical information-theoretic approach. 2nd edition
.
New York, New York
:
Springer-Verlag New York, Incorporated
.
Cross
FB,
Moss
RE.
1987
.
Historic changes in fish communities and aquatic habitats in plains streams of Kansas
.
Pages
155
165
in
Matthews
WJ,
Heins
DC,
editors.
Community and evolutionary ecology of North American stream fishes
.
Norman
:
University of Oklahoma Press
.
DeBoer
JA,
Pope
KL,
Koupal
KD.
2013
.
Environmental factors regulating the recruitment of walleye Sander vitreus and white bass Morone chrysops in irrigation reservoirs
.
Ecology of Freshwater Fisheries
22
:
43
54
.
Donald
DB.
1997
.
Relationship between year-class strength for Goldeyes and selected environmental variables during the first year of life
.
Transactions of the American Fisheries Society
126
:
361
368
.
Edsall
TA.
1967
.
Biology of the Freshwater Drum in western Lake Erie
.
The Ohio Journal of Science
67
:
321
340
.
Available: https://kb.osu.edu/handle/1811/5342 (August 2020).
Erickson
JW,
Rath
MD,
Best
D.
2008
.
Operation of the Missouri River reservoir system and its effects on fisheries management
.
Pages
117
134
in
MS,
Allen
Sammons
S,
Maceina
MJ,
editors.
Balancing fisheries management and water uses for impounded river systems
.
Bethesda, Maryland: American Fisheries Society. Symposium 62.
Falke
JA,
Bestgen
KR,
Fausch
KD.
2010
.
Streamflow reductions and habitat drying affect growth, survival, and recruitment of Brassy Minnow across a Great Plains riverscape
.
Transactions of the American Fisheries Society
139
:
1566
1583
.
Feyrer
F,
Sommer
T,
Harrell
W.
2006
.
Managing floodplain inundation for native fish: production dynamics of age-0 Splittail (Pogonichthys macrolepidotus) in California's Yolo Bypass
.
Hydrobiologia
573
:
213
226
.
Fincel
MF,
Chipps
SR,
Graeb
BDS,
Brown
ML.
2016
.
Diet breadth and variability in Sander spp. inferred from stable isotopes
.
River Research and Applications
32
:
984
991
.
Fincel
MF,
Chipps
SR,
Graeb
BDS,
Edwards
KR.
2013
.
Larval Gizzard Shad characteristics in Lake Oahe, South Dakota: a species at the northern edge of its range
.
Journal of Freshwater Ecology
28
:
17
26
.
Fincel
MF,
Dembkowski
DJ,
Chipps
SR.
2014
.
Influence of variable Rainbow Smelt and Gizzard Shad abundance on Walleye diets and growth
.
Lake and Reservoir Management
30
:
258
267
.
Fincel
MF,
Kludt
NB,
Meyer
HA,
Weber
M,
Longhenry
CM.
2019
.
Long-term data suggest potential interactions of introduced walleye and smallmouth bass on native sauger in four Missouri River impoundments
.
Journal of Fish and Wildlife Management
10
:
602
618
.
Fincel
MF,
Smith
MJ,
Hanten
RP,
Radigan
WJ.
2017
.
Recommendations for stocking Gizzard Shad in a large upper Midwest reservoir
.
North American Journal of Fisheries Management
37
:
599
604
.
Galat
DL,
Berry
CR,
Gardner
WM,
Hendrickson
JC,
Mestl
GE,
Power
GJ,
Stone
C,
Winston
MR.
2005
.
Spatiotemporal patterns and changes in Missouri River fishes
.
Pages 249–291 in
Rinne,
J.N.
Hughes,
R.M.
and
Calamusso,
B.
editors.
Historical changes in large river fish assemblages of the Americas
.
American Fisheries Society Symposium
45
:
249
291
.
Galat
DL,
Lipkin
R.
2000
.
Restoring ecological integrity of Great Rivers: historical hydrographs aid in defining reference conditions for the Missouri River
.
Hydrobiologia
422/423
:
29
48
.
Gido
KB,
Propst
DL,
Olden
JD,
Bestgen
KR.
2013
.
Multidecadal responses of native and introduced fishes to natural and altered flow regimes in the American Southwest
.
Canadian Journal of Fisheries and Aquatic Sciences
70
:
554
564
.
Gozlan
RE,
Britton
JR,
Cowx
I,
Copp
GH.
2010
.
Current knowledge on non-native freshwater fish introductions
.
Journal of Fish Biology
76
:
751
786
.
Graeb
BDS,
Willis
DW,
Billington
N,
Koigi
RN,
VanDeHey
JA.
2010
.
Age-structured assessment of Walleyes, Saugers, and naturally produced hybrids in three Missouri River reservoirs
.
North American Journal of Fisheries Management
30
:
887
897
.
Greiner
MJ,
Hanten
R,
Fincel
MJ,
Meyer
H,
Potter
K,
Smith
M.
2016
.
Annual fish population and angler use, harvest and preference surveys on Lake Sharpe, South Dakota, 2016
.
Pierre
:
South Dakota
Department of Game, Fish and Parks, Wildlife Division. Annual Report 17-03 (see Supplemental Material, Reference S1).
Haines
GB,
Tyus
HM.
1990
.
Fish associations and environmental variables in age-0 Colorado Squawfish habitats, Green River, Utah
.
Journal of Freshwater Ecology
427
435
.
Hair
JF
Jr,
Anderson
RE,
Tatham
RL,
Black
WC.
1995
.
Multivariate data analysis. 3rd edition
.
New York, New York
:
Macmillan
.
Hartman
KJ,
Margraf
FJ.
1992
.
Effects of prey and predator abundances on prey consumption and growth of Walleyes in Western Lake Erie
.
Transactions of the American Fisheries Society
121
:
245
260
.
Hayes
ML,
Ferreri
CP,
Taylor
WW.
1996
.
Active fish capture methods
.
Pages
193
220
in
Murphy
BR,
Willis
DW,
editors.
Fisheries techniques. 2nd edition
.
Bethesda, Maryland
:
American Fisheries Society
.
Hendrickson
JC,
Power
GJ.
1999
.
Changes in fish species abundance in a Missouri River main stem reservoir during its first 45 years
.
Journal of Freshwater Ecology
14
:
407
416
.
Hoagstrom
DW,
Hayer
C,
Berry
CR
Jr.
2006
.
Rare and declining fishes of South Dakota: a river drainage scale perspective
.
Proceedings of the South Dakota Academy of Science
85
:
171
211
.
Hosmer
DW,
Lemeshow
S.
1980
.
Goodness of fit statistics tests for the multiple regression model
.
Communications in Statistics
A9
:
1043
1069
.
Jackson
JJ,
Willis
DW,
Fielder
DG.
1992
.
Food habits of young-of-the-year Walleyes in Okobojo Bay of Lake Oahe, South Dakota
.
Journal of Freshwater Ecology
7
:
329
341
.
Jacquemin
SJ,
Doll
JC,
Pyron
M,
Allen
M,
Owen
DAS.
2015
.
Effects of flow regime on growth rate in freshwater drum, Aplodinotus grunniens
.
Environmental Biology of Fishes
98
:
993
1003
.
Kaemingk
MA,
Graeb
BDS,
Hoagstrom
CW,
Willis
DW.
2007
.
Patterns of fish diversity in a mainstem Missouri River reservoir and associated delta in South Dakota and Nebraska, USA
.
River Research and Applications
23
:
786
791
.
Karl
T,
Koss
WJ.
1984
.
Regional and national monthly, seasonal, and annual temperature weighted by area, 1895–1983. National Ocean and Atmospheric Administration
.
Historical Climatology Series 4-3
(see Supplemental Material, Reference S2).
Kiernan
JD,
Moyle
PB,
Crain
PK.
2012
.
Restoring native fish assemblages to a regulated California stream using the natural flow regime concept
.
Ecological Applications
22
:
1472
1482
.
Longhenry
C.
2013
.
Annual fish population and angler use and sportfish harvest surveys of Lewis and Clark Lake, South Dakota, 2013. South Dakota Department of Game, Fish and Parks, Wildlife Division
.
Annual Report 15-03
(see Supplemental Material, Reference S3).
Lott
J,
Fielder
D,
Johnson
B,
Riis
J,
Stone
C,
Wickstrom
G.
1994
.
Annual fish population surveys on South Dakota Missouri River reservoirs, 1993
.
Pierre
:
South Dakota
Department of Game, Fish and Parks, Wildlife Division. Annual Report 94-8 (see Supplemental Material, Reference S4).
MacRae
PSD,
Jackson
DA.
2001
.
The influence of Smallmouth Bass (Micropterus dolomieu) predation and habitat complexity on the structure of littoral zone fish assemblages
.
Canadian Journal of Fisheries and Aquatic Sciences
58
:
341
351
.
Markle
DF,
Dunsmoor
LK.
2007
.
Effects of habitat volume and Fathead Minnow introduction on larval survival of two endangered sucker species in Upper Klamath Lake, Oregon
.
Transactions of the American Fisheries Society
136
:
567
579
.
Martin
DB,
Mengel
LJ,
Novotny
JF,
Walburg
CH.
1981
.
Spring and summer water levels in a Missouri River reservoir: effects of age-0 fish and zooplankton
.
Transactions of the American Fisheries Society
110
:
70
381
.
Miranda
LE,
editor.
2017
.
Reservoir fish habitat management
.
Totowa, New Jersey
:
Lightning Press
.
[NOAA] National Oceanic and Atmospheric Administration National Centers for Environmental Information.
2018
.
Climate at a glance: statewide mapping
(see Supplemental Material, Reference S5).
Olden
JD,
Konrad
CP,
Melis
TS,
Kennard
MJ,
Freeman
MC,
Mims
MC,
Bray
EN,
Gido
KB,
Hemphill
NP,
Lytle
DA,
McMullen
LE,
Pyron
M,
Robinson
CT,
Schmidt
JC,
Williams
JG.
2014
.
Are large-scale flow experiments informing the science and management of freshwater ecosystems? Frontiers in Ecology and the Environment
.
Ostazèski
JJ,
Spangler
GR.
2001
.
Use of biochronology to examine interactions of Freshwater Drum, Walleye and Yellow Perch in the Red Lakes of Minnesota
.
Environmental Biology of Fishes
61
:
381
393
.
Pegg
MA,
Pierce
CL,
Roy
A.
2003
.
Hydrological alteration along the Missouri River Basin: a time series approach
.
Aquatic Sciences
65
:
63
72
.
Peterson
RC,
Jennings
CA.
2007
.
Effects of river discharge on abundance and instantaneous growth of age-0 Carpsuckers in the Oconee River, Georgia, USA
.
River Research and Applications
23
:
1016
1025
.
Pflieger
WL.
1997
.
The fishes of Missouri
.
Jefferson City
:
Missouri Department of Conservation
.
Pflieger
WL,
Grace
TB.
1987
.
Changes in fish fauna of the lower Missouri River, 1940–1983
.
Pages
166
167
in
Matthews
WJ,
Heins
DC,
editors.
Community and evolutionary ecology of North American stream fishes
.
Norman
:
University of Oklahoma Press
.
Poff
NL,
Allan
JD,
Bain
MB,
Karr
JR,
Prestegaard
KL,
Richter
BD,
Sparks
RE,
Stromberg
JC.
1997
.
The natural flow regime
.
BioScience
47
:
769
784
.
Potter
K,
Meyer
H,
Hanten
R,
Greiner
M,
Fincel
M,
Smith
M.
2015
.
Annual fish population and angler use, harvest and preference surveys on Lake Oahe, South Dakota, 2015
.
Pierre
:
South Dakota Department of Game, Fish and Parks, Wildlife Division, Annual Report 16-03 (see Supplemental Material, Reference S6)
.
Radigan
WJ,
Fincel
MJ.
2019
.
Factors affecting White Bass abundance in two Missouri River reservoirs
.
The Prairie Naturalist
51
:
3
16
(see Supplemental Material, Reference S7).
R Core Team.
2018
.
Version 3.5.1. R: a language and environment for statistical computing
.
Vienna, Austria
:
R Foundation for Statistical Computing
.
Available: http://www.r-project.org/ (June 2020).
Richard
JC,
Rypel
AL.
2013
.
Water body type influences climate–growth relationships of Freshwater Drum
.
Transactions of the American Fisheries Society
142
:
1308
1320
.
Rutherford
DA,
Kelso
WE,
Bryan
CF,
Constant
GC.
1995
.
Influence of physicochemical characteristics on annual growth increments of four fishes from the lower Mississippi River
.
Transactions of the American Fisheries Society
124
:
687
697
.
Rypel
AL,
Bayne
DR,
Mitchell
JB.
2006
.
Growth of Freshwater Drum from lotic and lentic habitats in Alabama
.
Transactions of the American Fisheries Society
135
:
987
997
.
Schlosser
IJ.
1985
.
Flow regime, juvenile abundance, and the assemblage structure of stream fishes
.
Ecology
66
:
1484
1490
.
Shapiro
SS,
Wilk
MB.
1965
.
An analysis of variance test for normality (complete samples)
.
Biometrika
52
:
591
611
.
Shoup
DE,
Wahl
DH.
2009
.
Fish diversity and abundance in relation to interannual and lake-specific variation in abiotic characteristics of floodplain lakes of the lower Kaskaskia River, Illinois
.
Transactions of the American Fisheries Society
138
:
1076
1092
.
Sorensen
J,
Knecht
G.
2006
.
Annual fish population and angler use and non-native fish harvest surveys on Lake Francis Case, South Dakota, 2004
.
Pierre
:
South Dakota
Department of Game, Fish and Parks, Fisheries Division. Report 06-20 (see Supplemental Material, Reference S8).
South Dakota Game, Fish and Parks.
2019
.
Fisheries and aquatic resources adaptive management system. 2019–2023 Missouri River Fisheries Management Area
.
South Dakota Game, Fish and Parks Wildlife Division. Northeast Fisheries Management Area Strategic Plan
(see Supplemental Material, Reference S9).
Sullivan
CL,
Koupal
KD,
Hoback
WW,
Peterson
BC,
Schoenebeck
CW.
2012
.
Food habits and abundance of larval Freshwater Drum in a south central Nebraska irrigation reservoir
.
Journal of Freshwater Ecology
27
:
111
121
.
Swedberg
DV.
1968
.
Food and growth of the Freshwater Drum in Lewis and Clark Lake, South Dakota
.
Transactions of the American Fisheries Society
97
:
442
447
.
Swedberg
DV,
Walburg
CH.
1970
.
Spawning and early life history of the Freshwater Drum in Lewis and Clark Lake, Missouri River
.
Transactions of the American Fisheries Society
99
:
560
570
.
[USGS] United States Geological Survey National Water Information System: Web Interface.
2018
.
Site inventory for the nation
(see Supplemental Material, Reference S10).
Walburg
CH.
1976
.
Changes in the fish populations of Lewis and Clark Lake, 1956–1974, and their relation to water management and the environment
.
Yankton, South Dakota
:
U.S. Fish and Wildlife Service
.
Research Report 79 (see Supplemental Material, Reference S11).
Wuellner
MR,
Chipps
SR,
Willis
DW,
Adams
WE
Jr.
2010
.
Interactions between Walleyes and Smallmouth bass in a Missouri River Reservoir with consideration of the influence of temperature and prey
.
North American Journal of Fisheries Management
30
:
445
463
.

Author notes

Citation: Radigan WJ, Fincel MJ. 2020. Factors related to age-0 native fish catch per unit effort in the South Dakota Missouri River reservoirs. Journal of Fish and Wildlife Management 11(2):618–633; e1944-687X. https://doi.org/10.3996/102019-JFWM-094

Competing Interests

The findings and conclusions in this article are those of the author(s) and do not necessarily represent the views of the U.S. Fish and Wildlife Service.