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Jonathan M. Vallazza

Publications and source records attributed to Jonathan M. Vallazza.

At least 19 recordsLinked to original sources
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

Tailwater residency patterns of Silver Carp at Kentucky Lock and Dam

Objective The management of invasive Silver Carp Hypophthalmichthys molitrix in the Tennessee River basin focuses on removal, and there is interest in extending removal efforts to the tailwater environments of high-head locks and dams along the Tennessee River, such as Kentucky Dam. We used acoustic telemetry data from Silver Carp to understand important ecological associations underlying their residence in the Kentucky Dam tailwater, measured by daily fish counts and mean residence time. Methods We used time-series-informed regression models, variance partitioning, and cross-correlation function analysis to associate six predictors, including lock and dam operations (total, spill gate, and turbine discharge and number of lockages), hydrology (tailwater elevation), and water temperature, with two measures of Silver Carp residency (daily counts and mean residence time). Results We found that spill-induced hydrology (total discharge + spill discharge + tailwater elevation) was negatively associated with daily counts but not with residence time, whereas temperature was positively associated with counts and negatively associated with residence times. Variance partitioning indicated that nearly all the variance in counts and residence times was jointly explained by temporal effects, lock and dam operations (discharge, tailwater elevation, and lockages), and temperature. The cross-correlations indicated that the counts were lagged by all predictors, sometimes up to 5 d, whereas residence times were lagged by both total and spill discharge and number of lockages. Conclusions We found that discharge and water temperature were principally associated with residency of Silver Carp in the Kentucky Dam tailwater. However, these associations were entirely temporally constrained, which can affect how strongly and how quickly Silver Carp respond to changing environmental conditions across different time scales. Managers can leverage these associations to plan removal periods where daily tailwater conditions/dam operations are favorable to invasive carp residence (e.g., >10°C and <2,500 m 3 /s) and adjust fishing effort to optimize removal rates in response to changing conditions.

Kentucky Lock and Dam↗
USGS2023

Predation of invasive silver carp by native largemouth bass is size-selective in the Illinois River

Silver carp ( Hypophthalmichthys molitrix ) are a nonnative, planktivorous, and highly invasive species of cyprinid located throughout the Mississippi River Basin. Although they co-occur with largemouth bass ( Micropterus nigricans ), an abundant native predatory fish, their predator–prey relationship is poorly understood. This potential relationship warrants investigation as largemouth bass are large-gaped predators capable of exhibiting top-down control on planktivorous fishes. The objectives of this study were to determine if largemouth bass consume juvenile silver carp, and if there was a relationship between length of largemouth bass and length of silver carp consumed. Largemouth bass were collected from the La Grange Pool of the Illinois River using 60 Hz-pulsed DC electrofishing and their diets were analyzed (n = 389, total length = 70–578 mm). Evidence of silver carp was present in 18% of diets of largemouth bass that consumed fish. Lengths of consumed silver carp were estimated from the dimensions of their recovered chewing pads or pharyngeal teeth in the stomachs of largemouth bass. A significant relationship between length of largemouth bass and length of silver carp consumed ( p < 0.001, F = 34.63, r 2 = 0.61) was observed. Estimated total lengths of silver carp were 34–101 mm and were recovered from diets of largemouth bass that were 94–262 mm total length. These results indicate enhancement of native largemouth bass populations is unlikely to substantially reduce silver carp populations in the Illinois River or in other waterways where these species co-occur.

Illinois↗
USGS2023

Multimodal invasive carp deterrent study at Barkley Lock and Dam—Status update through 2022

Invasive carp ( Hypophthalmichthys nobilis [Bighead Carp], Mylopharyngodon piceus [Black Carp], Ctenopharyngodon idella [Grass Carp], and H. molitrix [Silver Carp]) continue to spread in the United States and deterrents at river navigation locks are one emerging control strategy for slowing the spread. High-head navigation dams on large rivers serve as impediments to the upstream spread of these populations. One possible control technique is using a multimodal deterrent that utilizes a combination of lights, sound, and air bubbles to guide fish away from a location. Laboratory tests and small-scale field deployments of similar multi-stimuli deterrents have demonstrated potential for deterring invasive carp. These earlier studies led to the deployment and initiation of a field study of a multimodal deterrent in 2019 at the downstream lock approach at Barkley Lock and Dam on the Cumberland River near Grand Rivers, Kentucky. We are using two types of telemetry systems to evaluate how the multimodal deterrent affects movement and behavior of Silver Carp, Grass Carp, and four native species: Aplodinotus grunniens (Freshwater Drum), Polyodon spathula (Paddlefish), Ictiobus bubalus (Smallmouth Buffalo), and Acipenser fulvescens (Lake Sturgeon). We are evaluating fish movements in response to the multimodal deterrent by using a study design that cycles between 1 week with the multimodal deterrent on and 1 week with it off. This weekly cycling provides baseline comparisons across variable environmental conditions. When the multimodal deterrent is on, the number of Silver Carp completing upstream passage through Barkley Lock is reduced by about one-half. This study that began in 2019 can provide insights into the effectiveness of a multimodal deterrent for limiting upstream movement of invasive carp or effects on native fishes through strategic navigation locks on large rivers.

Kentucky↗
USGS2023

Lock 19 underwater acoustic deterrent system study—Interim project update, through 2022

Invasive carp ( Hypophthalmichthys nobilis [Richardson, 1845; Bighead Carp], H. molitrix [Valenciennes in Cuvier and Valenciennes, 1844; Silver Carp], Ctenopharyngodon idella [Valenciennes in Cuvier and Valenciennes, 1844; Grass Carp], and Mylopharyngodon piceus [Richardson, 1846; Black Carp]) expansion threatens the Laurentian Great Lakes and other major waterways. Numerous tools and techniques are being tested or developed to curtail the upstream expansion of invasive carps while minimizing the effect to native species. Underwater sound is one technology that has shown promise as a deterrent in the laboratory and ponds and is being considered for use at bottleneck locks and dams to reduce the risk of invasive carps moving to uninvaded areas. To test this technology at a management-relevant scale, an underwater acoustic deterrent system (UADS) was designed and installed at Lock 19 on the Mississippi River in 2021. The experimental UADS operates on a continuous schedule of 80 hours on and 80 hours off to allow for comparisons of fish behavior during varying environmental, operational, and navigation traffic conditions. Two telemetry systems, operating at 69 and 307 kilohertz, were deployed to evaluate how the UADS may affect movement and behavior of invasive carps and native fish species. During 2021–22, Silver Carp were twice as likely to pass over the UADS and into the lock when it was off compared to on; however, Bigmouth Buffalo, a native fish, were 1.2 times more likely to make upstream passage when the UADS was off compared to on.

Illinois, Iowa↗
USGS2022

Hydrological and lock operation conditions associated with paddlefish and bigheaded carp dam passage on a large and small scale in the Upper Mississippi River (Pools 14–18)

Movement and dispersal of migratory fish species is an important life-history characteristics that can be impeded by navigation dams. Although habitat fragmentation may be detrimental to native fish species, it might act as an effective and economical barrier for controlling the spread of invasive species in riverine systems. Various technologies have been proposed as potential fish deterrents at locks and dams to reduce bigheaded carp (i.e., silver carp and bighead carp ( Hypophthalmichthys spp.)) range expansion in the Upper Mississippi River (UMR). Lock and Dam (LD) 15 is infrequently at open-river condition (spillway gates completely open; hydraulic head across the dam <0.4 m) and has been identified as a potential location for fish deterrent implementation. We used acoustic telemetry to evaluate paddlefish passage at UMR dams and to evaluate seasonal and diel movement of paddlefish and bigheaded carp relative to environmental conditions and lock operations at LD 15. We observed successful paddlefish passage at all dams, with the highest number of passages occurring at LDs 17 and 16. Paddlefish residency events in the downstream lock approach of LD 15 occurred more frequently and for longer durations than residency events of bigheaded carp. We documented upstream passages completed by two individual paddlefish through the lock chamber at LD 15, and a single bighead carp completed upstream passage through the lock chamber during two separate years of this study. We identified four bigheaded carp and 19 paddlefish that made upstream passages through the spillway gates at LD 15 during this study. The majority of the upstream passages through the spillway gates for both species occurred during open river conditions. When hydraulic head was approximately 1-m or greater, we observed these taxa opt for upstream passage through the lock chamber more often than the dam gates. In years with infrequent open-river condition, a deterrent placed in the downstream lock approach may assist in meeting the management goal of reducing upstream passage of bigheaded carps but could also potentially affect paddlefish residency and passage. Continued study to understand the effects of deterrents on native fish could be beneficial for implementing an integrated bigheaded carp control strategy. Understanding fish behavior at UMR dams is a critical information need for river managers as they evaluate potential tools or technologies to control upstream expansion of bigheaded carp in the UMR.

Illinois, Iowa↗
USGS2021

Timing and hydrological conditions associated with bigheaded carp movement past navigation dams on the upper Mississippi river

As the range of non-native bigheaded carps ( Hypophthalmichthys spp.) continues to expand throughout river systems of the United States, managers are tasked with preventing or slowing the spread of these invasive species. Main stem navigation dams on the upper Mississippi River, long considered a deterrent to fish migration, may slow or prevent the spread of invasive fish species. As discharge increases, hydraulic head (i.e., difference between upstream elevation and downstream elevation) at these navigation dams decreases, which is believed to allow for easier fish passage. We used acoustic telemetry to investigate the occurrence, frequency, and timing of bigheaded carp passage of upper Mississippi River dams, along with factors related to successful dam passage. During 2013 through 2017, adult silver carp ( H. molitrix ), bighead carp ( H. nobilis ) and their hybrids (N = 358) were tracked throughout the upper Mississippi River. A total of 1078 dam passages by bigheaded carps (N = 158) were observed past 15 dams. Seventy-eight percent of dam passages occurred during April through July. Cox proportional hazards regression models indicated that both upstream and downstream dam passages by these species were strongly affected by hydraulic head height at the dam and water temperature, with dam passages increasing as hydraulic head decreased and water temperature increased. A few dams rarely experience low hydraulic head and passages of those dams by bigheaded carps were rare. This information can be used by managers to develop strategies (e.g., placement of deterrent technologies, targeted removal efforts) to slow the spread of these invasive species.

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗
USGS2020

Lock operations influence upstream passages of invasive and native fishes at a Mississippi River high-head dam

Asian carps continue to expand their range in North America, necessitating efforts to limit the spread and establishment of reproducing populations. Mississippi River Lock and Dam 19 is a high-head dam that represents a population ‘pinch-point’ as passage through the lock chamber is the only means by which fishes can complete upstream movement. As such, this location could be a pivotal control point for minimizing the spread of invasive fishes in the Upper Mississippi River and a possible candidate site for installation of deterrent measures. Our objectives were (1) to study the timing (i.e., weekly and diel) and behavior of fishes in the downstream lock approach, (2) evaluate the relation of presence in the downstream lock approach with environmental factors and lock operation, and (3) identify any upstream or downstream passage events through the lock chamber and the relation between these events and the operation of the lock. Acoustic transmitters were surgically implanted into 262 Asian carps and 216 native fishes to monitor fish activity on a telemetry receiver array deployed around and within the lock for 622 days during 2017–2018. One hundred eighty-six telemetered fish were detected in the downstream lock approach. We documented 14 upstream Asian carp passages and 10 upstream native fish passages; these passages coincided with a specific sequence of large vessel lockages. The results of this study advance our understanding of fish presence and behavior at a Mississippi River mainstem lock and dam and inform the development and testing of deterrent systems at this location or at similar pinch-point lock and dams.

Missouri, Iowa, Illinois↗
USGS2020

Influence of a high-head dam as a dispersal barrier to fish community structure of the Upper Mississippi River

In river systems, high‐head dams may increase the distance‐decay of fish community similarity by creating nearly impermeable dispersal barriers to certain species from upstream reaches. Substantial evidence suggests that migratory species are impacted by dams, and most previous studies in stream/river networks have focused on small streams and headwaters. Here, we assess whether a high‐head dam (Lock and Dam 19; LD 19) on a large river, the Upper Mississippi River (UMR), substantially alters fish community structure relative to variability expected to occur independent of the dam's effect as a fish dispersal barrier. Using fish catch per unit effort data, we modelled the distance‐decay function for the UMR fish community and then estimated the similarity that would be expected to occur across LD19 and compared it with measured similarity. Measured similarity in the fish community above and below LD19 was close to the expected value based on the distance‐decay function, suggesting LD19 does not create an abrupt transition in the fish community. Although some migratory fish species no longer occur above LD19 (e.g., skipjack herring, Alosa chrysochloris ), these species do not occur in high abundance below the dam and so do not drive variation in fish community structure. Instead, much of the variation in species structure is driven by the loss/gain of species across the latitudinal gradient. Lock and Dam 19 does not appear to be a clear transition point in the river's fish community, although it may function as a meaningful barrier for particular species (e.g., invasive species) and warrant future attention from a management perspective.

Illinois, Iowa Minnesota, Missouri, Wisconsin↗
USGS2019

Estimating the degree to which distance and temperature differences drive changes in fish community composition over time in the upper Mississippi River

Similarity in community composition declines as distance between locations increases, a phenomenon that has been observed in a wide variety of freshwater, marine and terrestrial ecosystems. One driver of the distance-similarity relationship is the presence of environmental gradients that alter the suitability of sites for particular species. Although some environmental gradients, such as geology, do not change on a year-to-year basis, others, such as temperature, vary annually and over longer time periods. Here, we used a 21-year dataset of fish communities in the upper Mississippi River to identify the effect of distance on variation in community composition and to assess whether the effect of distance is primarily due to its effect on thermal regime. Because the Mississippi River is aligned mostly north-to-south, larger distances along the river roughly correspond to larger differences in latitude and therefore temperature. As expected, there was a moderate distance-similarity relationship, suggesting greater distance leads to less similarity. The effect of distance appeared to increase slightly over time. Using a subset of data for which air temperature was available, we found that difference among sites in degree days (a surrogate for thermal regime) was more strongly associated with similarity in community composition than physical distance (river km). Although physical distance presumably incorporates more environmental gradients than just temperature (and other potential mechanisms), temperature alone appears to be more strongly associated with differences in the Mississippi River fish community.

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗
USGS2019

Evaluating potential effects of bigheaded carps on fatty acid profiles of multiple trophic levels in large rivers of the Midwest, USA

Recent work indicates that the establishment of bigheaded carps (Hypophthalmichthys spp.) in the United States has led to a reduction in condition of native planktivores and may detrimentally affect other trophic levels by altering the base of aquatic food webs. We used fatty acids to evaluate potential effects of bigheaded carps on taxa from multiple trophic levels in the Upper Mississippi, Illinois, and St. Croix rivers. Seston fatty acid concentrations were highest in the Illinois River lotic sites and connected backwaters and were positively associated with omega-3 highly unsaturated fatty acids, indicating that these locations had abundant, high-quality basal food resources despite hosting the greatest bigheaded carp densities. Fatty acid profiles of threeridge freshwater mussels tracked the fatty acid values in the seston and were not influenced by bigheaded carp abundances. Hydropsychid caddisflies and bluegill did not differ significantly in total fatty acids or percent lipid among spatial locations, indicating that omnivorous species may be relatively unaffected by bigheaded carps. Gizzard shad, however, exhibited the lowest fatty acid concentrations in the locations with the highest relative bigheaded carp densities, and multivariate models identified bigheaded carp densities as the predictive factor that explained the greatest amount of variability. Zooplankton abundance has been greatly reduced after bigheaded carps establishment in the Illinois River, which may explain the disconnect between the gizzard shad fatty acids and the plentiful, high-quality phytoplankton in that river. Our data provide additional evidence that bigheaded carps are negatively affecting native planktivores such as gizzard shad.

Minnesota, Iowa, Missouri, Wisconsin, Illinois, Mi↗
USGS2018

Spatial and temporal variance in fatty acid and stable isotope signatures across trophic levels in large river systems

Fatty acid and stable isotope signatures allow researchers to better understand food webs, food sources, and trophic relationships. Research in marine and lentic systems has indicated that the variance of these biomarkers can exhibit substantial differences across spatial and temporal scales, but this type of analysis has not been completed for large river systems. Our objectives were to evaluate variance structures for fatty acids and stable isotopes (i.e. δ13C and δ15N) of seston, threeridge mussels, hydropsychid caddisflies, gizzard shad, and bluegill across spatial scales (10s-100s km) in large rivers of the Upper Mississippi River Basin, USA that were sampled annually for two years, and to evaluate the implications of this variance on the design and interpretation of trophic studies. The highest variance for both isotopes was present at the largest spatial scale for all taxa (except seston δ15N) indicating that these isotopic signatures are responding to factors at a larger geographic level rather than being influenced by local-scale alterations. Conversely, the highest variance for fatty acids was present at the smallest spatial scale (i.e. among individuals) for all taxa except caddisflies, indicating that the physiological and metabolic processes that influence fatty acid profiles can differ substantially between individuals at a given site. Our results highlight the need to consider the spatial partitioning of variance during sample design and analysis, as some taxa may not be suitable to assess ecological questions at larger spatial scales.

River Research and Applications↗
USGS2017

Using pharyngeal teeth and chewing pads to estimate juvenile Silver Carp total length in the La Grange Reach, Illinois River

The Silver Carp Hypophthalmichthys molitrix is an invasive species in the Mississippi River basin; an understanding of their vulnerability to predation as juveniles may inform control by native predators and predator enhancement (e.g., stocking). Digestion of Silver Carp prey recovered from diets makes it difficult to determine the size‐classes that are most vulnerable to predation by native fishes. The objective of this study was to determine whether the sizes of the chewing pad (CP), pharyngeal teeth (PT), and pharyngeal arch (PA)—the Silver Carp structures most often found intact in predator diets—were predictive of the TL of prey Silver Carp. During 2014 and 2015, juvenile Silver Carp ( n = 136; <180 mm) were collected using 60‐Hz pulsed‐DC electrofishing and mini‐fyke nets in the La Grange reach of the Illinois River. We extracted Silver Carp CPs ( n = 136 fish) and PAs with PT intact ( n = 129 fish) and measured CP length (CP L ) and width (CP W ), eight reproducible PT landmarks (PT1 L –PT4 L ; PT1 W –PT4 W ), and four reproducible PA landmarks (PA1–PA4) to the nearest 0.01 µm. Using simple linear regression, we found a strong predictive relationship between measurements of CP, PT, or PA and the TL of Silver Carp. The CP L ( r 2 = 0.94) and CP W ( r 2 = 0.94) had the strongest relationships with Silver Carp TL, followed by PA1 ( r 2 = 0.89) and PT1 L ( r 2 = 0.87). These strong relationships suggest that all three structures could be used in diet analyses to accurately estimate Silver Carp TL and thus further our understanding of predator–prey dynamics for this high‐risk invasive species.

Illinois↗
USGS2017

Evidence of Asian carp spawning upstream of a key choke point in the Mississippi River

Bighead Carp Hypophthalmichthys nobilis , Silver Carp H. molitrix , and Grass Carp Ctenopharyngodon idella (collectively termed “Asian carp”) were introduced into North America during the 1960s and 1970s and have become established in the lower Mississippi River basin. Previously published evidence for spawning of these species in the upper Mississippi River has been limited to an area just downstream of Dam 22 (near Saverton, Missouri). In 2013 and 2014, we sampled ichthyoplankton at 18 locations in the upper Mississippi River main stem from Dam 9 through Dam 19 and in four tributaries of the Mississippi River (Des Moines, Skunk, Iowa, and Wisconsin rivers). We identified eggs and larvae by using morphological techniques and then used genetic tools to confirm species identity. The spawning events we observed often included more than one species of Asian carp and in a few cases included eggs that must have been derived from more than one upstream spawning event. The upstream extent of genetically confirmed Grass Carp ichthyoplankton was the Wisconsin River, while Bighead Carp and Silver Carp ichthyoplankton were observed in Pool 16. In all these cases, ichthyoplankton likely drifted downstream for several hours prior to collection. Higher water velocities (and, to a lesser extent, higher temperatures) were associated with an increased likelihood of observing eggs or larvae, although the temperature range we encountered was mostly above 17°C. Several major spawning events were detected in 2013, but no major spawning events were observed in 2014. The area between Dam 15 and Dam 19 appears to be the upstream edge of spawning activity for both Silver Carp and Bighead Carp, suggesting that this area could be a focal point for management efforts designed to limit further upstream movement of these species. .

Upper Mississippi River↗
USGS2017

Using a gradient in food quality to infer drivers of fatty acid content in two filter-feeding aquatic consumers

Inferences about ecological structure and function are often made using elemental or macromolecular tracers of food web structure. For example, inferences about food chain length are often made using stable isotope ratios of top predators and consumer food sources are often inferred from both stable isotopes and fatty acid (FA) content in consumer tissues. The use of FAs as tracers implies some degree of macromolecular conservation across trophic interactions, but many FAs are subject to physiological alteration and animals may produce those FAs from precursors in response to food deficiencies. We measured 41 individual FAs and several aggregate FA metrics in two filter-feeding taxa to (1) assess ecological variation in food availability and (2) identify potential drivers of among-site variation in FA content. These taxa were filter feeding caddisflies (Family Hydropyschidae) and dreissenid mussels (Genus Dreissena ), which both consume seston. Stable isotopic composition (C and N) in these taxa co-varied across 13 sites in the Great Lakes region of North America, indicating they fed on very similar food resources. However, co-variation in FA content was very limited, with only one common FA co-varying across this gradient (α-linolenic acid; ALA), suggesting these taxa accumulate FAs very differently even when exposed to the same foods. Based on these results, among-site variation in ALA content in both consumers does appear to be driven by food resources, along with several other FAs in dreissenid mussels. We conclude that single-taxa measurements of FA content cannot be used to infer FA availability in food resources.

Lake Erie, Lake Huron, Lake Michigan, Lake Ontario↗