Geology topics

Research about upper Mississippi River

Source-linked reports with geographic coverage including upper Mississippi River.

10 recordsLinked to original sources

USGS2026

Life history traits and population dynamics of Freshwater Drum across large river gradients

Objective Monitoring and assessment of nongame native fishes is limited, but conservation interest in these species is growing. Freshwater Drum Aplodinotus grunniens are a wide-ranging species that serve important functional roles and could serve as an indicator for similar but less common species. Our overall objectives were to quantify and compare population dynamic rates and life history of Freshwater Drum among study reaches in the upper Mississippi and Illinois rivers and relate these metrics to hypothesized environmental and anthropogenic factors. Methods We integrated recently collected age data with monitoring data to estimate age and size distributions, growth curves, maturation schedules, mortality rates, and young-to-adult ratios of Freshwater Drum in six study reaches spanning 1,500 km of river. Principal component analyses and linear regression were used to relate environmental and anthropogenic gradients (latitude, commercial harvest, hydrologic dynamics, primary productivity) to life history traits and population dynamic rates. Results We found latitudinal gradients in life history traits and population dynamic rates whereby Freshwater Drum in upstream, higher-latitude study reaches generally exhibited later maturity, slower growth, smaller maximum size, and lower mortality rates compared with those in lower-latitude study reaches. Further, young-to-adult ratios positively corresponded with chlorophyll- a concentration. No clear relationships were apparent between population dynamic rates and hydrologic variation or commercial harvest. Conclusions Latitude is an important structuring component of life history traits and population dynamics of Freshwater Drum in the upper Mississippi and Illinois rivers likely due to both temperature seasonality and disturbance regimes. The presence of demographic structure in a widespread, common species such as Freshwater Drum suggests similar patterns likely exist in other long-lived native fishes.

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗

USGS2026

Silver Carp Hypophthalmichthys molitrix broad movement patterns and dispersal dynamics in the upper Mississippi River

Rivers are important movement corridors for fishes that allow for population connectivity. Within the upper Mississippi River Basin, invasive Silver Carp ( Hypophthalmichthys molitrix ) use tributaries including the Des Moines, Iowa, and Cedar rivers; however, the extent Silver Carp move and intermix among these systems and pools of the upper Mississippi River (UMR) is largely unknown. We used acoustic telemetry and multistate models to (1) identify individual and spatial variability in movement strategies, (2) use survival and transition probability estimates to evaluate population dynamics and connectivity, and (3) evaluate the influence of temporal and environmental variables on survival and transition probabilities. Weekly transition probabilities generally increased with discharge and ranged between 0.01 from UMR Pool 20 to outside the study area at 575 m 3 /s to 0.75 from UMR Pool 18 to outside the study area at 7200 m 3 /s. Survival decreased as temperature increased from 0 to 30 °C and was higher in tributaries than mainstem pools correlated with lower discharge. Overall, Silver Carp displayed diverse movement strategies with high connectivity that can inform invasive species management strategies.

upper Mississippi River↗

USGS2025

Off-channel habitat use by silver carp (Hypophthalmichthys molitrix) and bighead carp (H. nobilis) in the upper Mississippi River

The spread of invasive carp in the Mississippi River Basin of the U.S. has caused substantial ecological and economic problems. Although there are a variety of strategies to manage invasive carp, removal remains a central part of many efforts. To be most effective, large-scale removal of invasive carp should target fish when they are densely aggregated in locations with favorable conditions for deploying fishing gear. We used acoustic telemetry to track off-channel habitat use by silver carp Hypophthalmichthys molitrix and bighead carp H. nobilis in backwaters and impounded areas across three navigation pools of the upper Mississippi River to identify factors associated with high densities. Backwater areas generally had high use when temperatures were warm and river discharge was high, and impounded areas generally had high use when temperatures were cooler and discharge was lower. Models of habitat use suggest silver carp and bighead carp show predictable habitat relationships in off-channel areas that could improve removal efficiency.

Illinois, Iowa, Missouri↗

USGS2025

Exploring the importance of metapopulation dynamics with population control strategies for invasive silver carp in the upper Mississippi River

Invasive bigheaded carps (Bighead Carp Hypophthalmichthys nobilis , Silver Carp Hypophthalmichthys molitrix , and their hybrids Hypophthalmichthys spp.) currently infest the Mississippi River Basin. Bigheaded carps can outcompete native species in invaded waters and can also transform the surrounding environment. Currently, resource managers seek to limit the population abundance of bigheaded carps and their range expansion into additional regions of the Upper Mississippi River (UMR) but lack a tool to evaluate different control strategies. Here, we present an application of a Silver Carp spatial population model in the UMR to fill this gap. We used the model to explore how simulated control strategies could affect Silver Carp metapopulation dynamics. More specifically, we assessed and compared the importance of movement deterrents, removal locations, and recruitment areas on Silver Carp population abundances across the UMR. Strategies that included a combination of removal efforts and deterrents resulted in the largest decreases in Silver Carp abundance in the upper pools of the UMR. Furthermore, scenarios that targeted source populations of Silver Carp rather than sink populations resulted in larger decreases in Silver Carp abundance at the invasion front. The effectiveness of these combined simulated strategies also depended on the location of Silver Carp recruitment. Our work suggests that an understanding of Silver Carp metapopulation dynamics may be important for control efforts and could help to inform the management of Silver Carp in the UMR.

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗

USGS2025

Characterizing the niche of Phalaris arundinacea (reed canarygrass) in floodplain forests of the Upper Mississippi River

Information on the favorable conditions for invasive species as well as potential constraints to their distribution can be valuable for management efforts. We used a niche modeling approach to analyze the patterns of species distributions along gradients of hypothesized influential environmental variables. Many ecological datasets may have incomplete coverage across the environmental gradients, infrequent sampling under some conditions, insufficient time for an invasive species to occupy all sites, and complex interactions among environmental variables (measured or unmeasured) that may result in species response curves that are difficult to interpret and may be ecologically misleading. To ensure the model and species response curves aligned with ecological niche theory, shape constraints were imposed to guarantee relationships follow a unimodal distribution to reflect the fundamental niche (where a species could occur). We compared a shape-constrained model to an unconstrained model and interpreted the species response curves from the constrained model to better characterize the ecological niche of reed canarygrass in floodplain forests of the Upper Mississippi River, USA. We found the probability of reed canarygrass occurrence decreases with increasing tree canopy cover, tree species richness, distance from forest edge, distance from invaded wet meadows, and island isolation. Probability of reed canarygrass presence exhibited bell-shaped curves in response to hydrology (inundation depth, frequency, and duration) and forest stress metrics indicating an optimum with less favorable conditions on either end of the ecological gradients. This information could be used to prioritize restoration efforts and enhance landcover change research in forested floodplains.

upper Mississippi River↗

USGS2025

Climate and connectivity mediate overwintering habitat suitability for centrarchids in a large floodplain river network

Availability of suitable overwintering habitat is crucial for the survival of centrarchids in large floodplain rivers. However, there remains uncertainty in the spatiotemporal drivers of suitable conditions. We paired hydrogeomorphic characteristics with environmental data from 1994 to 2018 in individual lentic areas to (1) assess overwintering habitat availability throughout the Upper Mississippi River System using existing habitat suitability indices (HSIs) and (2) explore potential drivers of overall habitat suitability (HSI O ) and its components (dissolved oxygen, temperature, and flow). We found that flow velocities that exceeded suitable thresholds were independently responsible for 53% of nonsuitable habitats, and connectivity with lotic channels and river discharge increased velocity within lentic habitats. Additionally, colder winter conditions reduced water temperature, reducing availability of highly suitable habitat. Our results indicate that although warmer winters could increase the availability of highly suitable habitat for centrarchids, changes in flow regimes could lead to more connected areas becoming unsuitable. Our results provide critical information on factors that can be prioritized to manage centrarchid habitat, which is especially important in the context of uncertain future climate.

upper Mississippi River↗

USGS1993

Growth and mortality of larval sunfish in backwaters of the upper Mississippi River

We estimated the growth and mortality of larval sunfish Lepomis spp. in backwater habitats of the upper Mississippi River with an otolith‐based method and a length‐based method. Fish were sampled with plankton nets at one station in Navigation Pools 8 and 14 in 1989 and at two stations in Pool 8 in 1990. For both methods, growth was modeled with an exponential equation, and instantaneous mortality was estimated by regressing the natural logarithm of fish catch for each 1‐mm size‐group against the estimated age of the group, which was derived from the growth equations. At two of the stations, the otolith‐based method provided more precise estimates of sunfish growth than the length‐based method. We were able to compare length‐based and otolith‐based estimates of sunfish mortality only at the two stations where we caught the largest numbers of sunfish. Estimates of mortality were similar for both methods in Pool 14, where catches were higher, but the length‐based method gave significantly higher estimates in Pool 8, where the catches were lower. The otolith‐based method required more laboratory analysis, but provided better estimates of the growth and mortality than the length‐based method when catches were low. However, the length‐based method was more cost‐effective for estimating growth and mortality when catches were large.

upper Mississippi River↗

USGS1988

Variations in abundance of young-of-the-year channel catfish in a navigation pool of the upper Mississippi River

Spatial and temporal variations in the abundance of young‐of‐the‐year channel catfish Ictalurus punctatus were determined over 3 years based on 154 trawls taken from Navigation Pool 7 of the upper Mississippi River. No significant spatial patterns in abundance or length offish in the catch were found in seven poolwide surveys of the main channel. However, high variation among replicates existed. Temporal patterns in abundance and length‐frequency distributions varied among the study years. Seasonal catch curves were similar in 1984 and 1986, although offset due to earlier spawning in 1986. Spawning appeared to have been protracted in both years, based on analyses of back‐calculated dates of spawn and length‐frequency patterns of young. Sixty to seventy percent more young were produced in 1985, when spawning occurred over a shorter period of time and a more uniformly sized year class was produced. These annual variations in year‐class characteristics are hypothesized to have resulted in part from different river discharge patterns in the 3 years of the survey, with high discharge in 1984 and 1986 negatively affecting production of young.

upper Mississippi River↗

USGS1987

Effect of brief navigation-related dewaterings on fish eggs and larvae

Short-term dewatering of nearshore spawning areas often occurs during passage of commercial tows in the upper Mississippi River as well as in other navigated river systems. This phenomenon was examined experimentally to identify potential effects on survival of fish eggs and larvae. Early life stages of walleyes ( Stizostedion vitreum vitreum ) and northern pike ( Esox lucius ) were dewatered 2 min in laboratory studies at intervals of either 1, 3, 6, or 12 h from just after fertilization to 10-14 d posthatch. Dewatering did not cause mortality of eggs, but significant mortality of larvae of both species occurred at dewatering frequencies of 1 or 3 h. Therefore, significant mortality first was observed at a frequency equivalent to a mean passage of eight tows per day.

upper Mississippi River↗

USGS1983

Distribution of larval fishes related to potential navigation impacts on the upper Mississippi River, pool 7

Ichthyoplankton samples were collected twice monthly during spring and summer 1981 from a variety of habitats in Navigation Pool 7 of the upper Mississippi River. Larval‐fish distributions in the pool and variations in those distributions were analyzed relative to potential impacts of increased commercial navigation. Although as many as 66 species of adults have been found in the area (33 considered common), only 17 taxa were identified from our collections. In April and May, most larvae were collected in main‐channel and main‐channel‐border areas next to major expanses of shallow backwaters. White bass Morone chrysops, yellow perch Perca flavescens, and crappies Pomoxis spp. were predominant. Numerous catostomids also were taken. In June and July, most larvae were taken in the lower pool. Freshwater drum Aplodinotus grunniens and gizzard shad Dorosoma cepedianum predominated in these samples, which also included many cyprinids and centrarchids. Diel patterns of abundance varied with species and sampling location. Freshwater drums were more abundant near the surface at midnight than during the day. Common carp Cyprinus carpio were most abundant in collections at dusk, whereas all other cyprinids were most abundant at dusk and dawn. Numbers of gizzard shad also increased slightly at dusk. Total numbers of larvae collected were greatest at dusk in main‐channel and main‐channel‐border samples; backwater areas produced the greatest catches at midnight and dawn. Seasonal, spatial, diel, and species‐specific variations in larval fish abundances significantly influenced the proportion of the community potentially vulnerable to increased boat traffic through Pool 7.

upper Mississippi River↗