Geology topics

Steven J. Zigler

Publications and source records attributed to Steven J. Zigler.

14 recordsLinked to original sources

USGS2022

Assessment of a habitat equivalency analysis for freshwater mussels in the upper Mississippi River

The upper Mississippi River (UMR) contains diverse, dense, and reproducing assemblages of native freshwater mussels. In the case of an injury to mussels and their habitats, such as a hazardous material spill, train derailment, or barge grounding, resource managers have few restoration strategies. Resource managers need a means to document, quantify, and mitigate adverse effects on mussels resulting from injury. Habitat equivalency analysis (HEA), developed for use with a wide variety of habitat types, is a restoration scaling technique that compares ecological services lost from injury to ecological services gained through restoration actions. The U.S. Fish and Wildlife Service and Iowa Department of Natural Resources modified the HEA for use with native mussels. The mussel HEA has been applied within the UMR to estimate the quantity of restoration needed to compensate the public for injuries to mussels due to contaminant spills and construction projects. Our objective was to describe the UMR HEA for a general audience and assess if the four biological input variables used in the mussel HEA were reasonable based on literature values. We also evaluated the performance of HEA under a range of input scenarios. Although the input estimates used in HEA were within ranges reported in the peer-reviewed literature or were supported by professional judgment in the absence of peer-reviewed literature, outcomes of the mussel HEA were highly variable and would benefit from additional research to reduce uncertainty in the biological inputs. The application of HEA to mussels provides resource managers with a tool to quantify mussel-related ecological services lost from injury and to guide restoration efforts in the UMR.

Freshwater Mollusk Biology and Conservation↗

USGS2021

Assessing the migratory histories, trophic positions, and conditions of lake sturgeon in the St. Croix and Mississippi Rivers using fin ray microchemistry, stable isotopes, and fatty acid profiles

Background Reproducing populations of invasive carps ( Hypophthalmichthys spp.) could alter aquatic food webs and negatively affect native fishes in the Mississippi National River and Recreation Area (MISS) and the St. Croix National Scenic Riverway (SACN). However, proposed invasive carp barriers may also threaten populations of native migratory fishes by preventing movements of fish between rivers that are necessary for life history requirements. In this study, nonlethal chemical techniques were used to provide baseline data related to the condition, trophic position, and migratory histories of lake sturgeon ( Acipenser fulvescens ) captured in the Mississippi and St. Croix Rivers. Results Fish length and weight measurements and age estimates determined from pectoral fin rays demonstrated that lake sturgeon from the Mississippi River had greater lengths-at-age compared to sturgeon from the St. Croix River. However, length–weight relations were similar for sturgeon from the Mississippi and St. Croix Rivers. Lake sturgeon captured from different locations had distinguishable fatty acid signatures, and stable isotope analyses demonstrated that lake sturgeon from the Mississippi River generally feed at a higher trophic level than those in the St. Croix River. Strontium-to-calcium ratios (Sr:Ca) from fin ray cross sections indicated that sturgeon captured from the Mississippi River had higher Sr:Ca values than sturgeon captured from the St. Croix River, and natal origins and capture locations were not significantly different among sturgeon captured within individual rivers. Most sturgeon were captured in water with a similar Sr:Ca signature as their natal waters, indicating that there is some separation between populations of lake sturgeon in the St. Croix and Mississippi Rivers. However, Sr:Ca data indicated substantial variation in movement patterns among individual lake sturgeon, indicating that populations interact through migrations of individual fish between rivers. Conclusions Study results provide baseline condition and food web structure index data for assessing changes in lake sturgeon populations should invasive carps become established in these areas of the Mississippi and St. Croix Rivers. Controlled-exposure and telemetry studies would help verify and enhance the relations between Sr:Ca signatures in water and lake sturgeon pectoral fin rays to further assess mixing of sturgeons between rivers.

Minnesota, Wisconsin↗

USGS2020

Estimation of vital population rates to assess the relative health of mussel assemblages in the Upper Mississippi River

Native freshwater mussels are a guild of benthic, filter feeding invertebrates that perform important ecological functions in rivers. Because of their long lifespans (30–50 years or longer), mussels are slow to respond to human‐induced alterations. Thus, development of sensitive indicators of mussel population responses to river conditions and management would be beneficial. Compared to marine species, estimation of vital rates (e.g. survival, growth) in freshwater mussels has received little attention. We placed passively integrated transponder tags on 578 mussels of four species ( Amblema plicata , Cyclonaias pustulosa , Obliquaria reflexa , and Pleurobema sintoxia ) in a well‐studied mussel assemblage in a side channel of the upper Mississippi River. Growth and survival of tagged mussels were assessed annually for 4 years across core (high density) and peripheral (low density) areas of the assemblage. Overall survival was highly variable, ranging from c . 15 to 90%, and was related to life history, habitat quality, and hydrologic events. Survival, which varied significantly among species and over time, was consistently higher in the dense and species‐rich core of the mussel assemblage, relative to the periphery because substrates were consistently more stable in the core of the mussel bed relative to the periphery. Substrate movement during low flows was an order of magnitude lower in the core relative to the periphery, and survival was inversely related to stability of river substrates. Patterns in habitat‐specific survival indicate source–sink population dynamics such that mussels in the core habitat provide recruitment to the periphery, but mussels in the periphery are subject to unsustainably low survival; additional studies to track the source of recruitment in the periphery are needed to test this hypothesis. Growth rate did not vary significantly between core and peripheral areas but did vary by species. Growth rate (proportional change per year) declined with age, and was similar at mean age for A. plicata (0.016 per year), P. sintoxia (0.015 per year), and C. pustulosa (0.013 per year), but much lower for O. reflexa (0.008 per year). Effective management decisions for mussels requires a better understanding of how vital rates govern populations and how they vary across a suite of physical and biological factors. Information on how population vital rates vary among species and over time gives managers another tool to understand how mussels may respond to management actions such as habitat restoration projects. Given the importance of substrate stability inferred from this study, management actions that maintain or increase substrate stability are likely to result in high quality mussel assemblages and may restore a valuable component of ecosystem function in this region.

Minnesota, Wisconsin↗

USGS2020

Mussel community assessment tool for the Upper Mississippi River system

Upper Mississippi River (UMR) resource managers need a quantitative means of evaluating the health of mussel assemblages to measure effects of management and regulatory actions, assess restoration techniques, and inform regulatory tasks. Our objective was to create a mussel community assessment tool (MCAT), consisting of a suite of metrics and scoring criteria, to consistently compare the relative health of UMR mussel assemblages. We developed an initial MCAT using quantitative data from 25 sites and 10 metrics. Metrics fell in five broad groups: conservation status and environmental sensitivity, taxonomic composition, population processes, abundance, and diversity. Metric scoring categories were based on quartile analysis: 25% scoring as good, 50% scoring as fair, and 25% scoring as poor. Scores were meant to facilitate establishing management priorities and mitigation options for the conservation of mussels. Scoring categories assumed that a healthy mussel assemblage consists of species with a variety of reproductive and life-history strategies, a low percentage of tolerant species, and a high percentage of sensitive species; shows evidence of adequate recruitment, a variety of age classes, and low mortality; and has high abundance, species richness, and species and tribe evenness. Metrics were validated using a modified Delphi technique. MCAT metrics generally reflected the professional opinions of UMR resource managers and provided a consistent evaluation technique with uniform definitions that managers could use to evaluate mussel assemblages. Additional data sets scored a priori by UMR resource managers were used to further validate metrics, resulting in data from 33 sites spanning over 980 km of the UMR. Initial and revised MCAT scores were similar, indicating that data represent the range of mussel assemblages in the UMR. Mussel assemblages could be evaluated using individual metrics or a composite score to suit management purposes. With additional data, metrics could be calibrated on a local scale or applied to other river systems.

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗

USGS2019

Local scale spatial patterns of freshwater mussels in the Upper Mississippi River

Multiple physical and biological factors contribute to the structure of freshwater mussel communities in large rivers. Mussel distributions are frequently described as clumped or patchy. However, few surveys of mussel populations have been designed to quantify these spatial patterns. We used indicators of spatial autocorrelation to quantify spatial patterns of adult and juvenile (≤ 5 years of age) freshwater mussels at local scales (i.e., < 300 m), within 14 sites along ~700 km of the Upper Mississippi River, USA. Juveniles were patchily distributed in 43% of the sites, and adults were patchily distributed in 50%. Within sites, juveniles and adults displayed the same spatial pattern in 64% of the sites. At half of the sites, hotspots of adults and juveniles overlapped suggesting spatial and temporal persistence of habitat. Mussels have an important ecological role in rivers, and information on their spatial patterns aid our understanding of the spatial structure and function of riverine ecosystems, and the ecological consequences of population declines.

Illinois, Iowa, Minneapolis, Wisconsin↗

USGS2018

Method comparisons for determining concentrations of metals in water samples used in studies of fish migratory histories

Signatures developed from metal concentrations in water and fish bony structures can be used to demonstrate migration of individual fish between connected water bodies. The U.S. Geological Survey (USGS), in cooperation with the National Park Service and the Missouri Department of Conservation, compared two protocols for collecting and analyzing water samples for concentrations of several metals commonly used to develop metal signatures. In 2015, paired seasonal water samples were collected in two study areas incorporating three National Park Service units; paired water samples were collected using USGS protocols and simpler research protocols. Metal concentrations obtained using USGS and research protocols were compared using t-tests, percent differences, and simple linear regression analyses. Graphical plots of median values and measured ranges were used to compare ratios of strontium to calcium (Sr:Ca) and barium to calcium (Ba:Ca) obtained using the different protocols among individual stations within the two study areas. For stations on the Mississippi and St. Croix Rivers, ranges in concentrations of calcium, barium, and strontium (obtained using USGS protocols) were compared between samples collected from 1995 through 2012 and samples collected in this study. Comparisons were used to evaluate the long-term stability of metal concentrations in the environment. Collectively, results presented in this report demonstrated that research protocols provided metal concentration data that were similar to data obtained using USGS protocols for all compared metals except manganese. Holding times of 6–33 weeks prior to filtration and analyses for samples collected using research protocols may have caused greater changes in manganese concentrations compared to other metals. Strontium, barium, and calcium are the metals most commonly used in studies of fish migration, and concentrations of these metals were similar using different protocols. However, rivers within each study area were more easily distinguished from each other using metal concentration data obtained using USGS protocols compared to data obtained using research protocols. Information presented in this report can be used to develop studies that use identified metal signatures in connected water bodies and bony fish structures to demonstrate fish migration.

Mississippi National River and Recreation Area, Na↗

USGS2016

Spatial patterns of native freshwater mussels in the Upper Mississippi River

Multiple physical and biological factors structure freshwater mussel communities in large rivers, and their distributions have been described as clumped or patchy. However, few surveys of mussel populations have been conducted over areas large enough and at resolutions fine enough to quantify spatial patterns in their distribution. We used global and local indicators of spatial autocorrelation (i.e., Moran’s I) to quantify spatial patterns of adult and juvenile (≤5 y of age) freshwater mussels across multiple scales based on survey data from 4 reaches (navigation pools 3, 5, 6, and 18) of the Upper Mississippi River, USA. Native mussel densities were sampled at a resolution of &sim;300 m and across distances ranging from 21 to 37 km, making these some of the most spatially extensive surveys conducted in a large river. Patch density and the degree and scale of patchiness varied by river reach, age group, and the scale of analysis. In all 4 pools, some patches of adults overlapped patches of juveniles, suggesting spatial and temporal persistence of adequate habitat. In pools 3 and 5, patches of juveniles were found where there were few adults, suggesting recent emergence of positive structuring mechanisms. Last, in pools 3, 5, and 6, some patches of adults were found where there were few juveniles, suggesting that negative structuring mechanisms may have replaced positive ones, leading to a lack of localized recruitment. Our results suggest that: 1) the detection of patches of freshwater mussels requires a multiscaled approach, 2) insights into the spatial and temporal dynamics of structuring mechanisms can be gained by conducting independent analyses of adults and juveniles, and 3) maps of patch distributions can be used to guide restoration and management actions and identify areas where mussels are most likely to influence ecosystem function.

Upper Misssissippi River↗

USGS2015

Annual variation in recruitment of freshwater mussels and its relationship with river discharge

Vital rates such as mortality, growth, and recruitment are important tools to evaluate the status of threatened populations and identify their vulnerabilities, leading to enhanced conservation strategies. Native freshwater mussels are a guild of largely sedentary, filter-feeding bivalves currently facing worldwide declines. Lack of recruitment has been identified as a major threat to mussel populations. A mussel bed in the Upper Mississippi River was sampled for 5 years (2008–2012). A trend analysis showed a significant decline in the percentage of species with juvenile representatives. Species were grouped into equilibrium and periodic life history strategies to assess past recruitment. Residuals from catch-curve regressions quantified past year-class strength of both strategists and Amblema plicata over a 13-year period (1994–2006), and identified strong and weak year-classes. Generalized linear regression models containing July maximum discharge and April minimum discharge explained 64% of the variation in recruitment strength of A. plicata . The best model for the equilibrium strategists explained 86% of the variation in recruitment and contained the same variables as A. plicata, but also incorporated the 7-day minimum discharge. For the periodic strategists, the model containing the number of low-flow pulses and the mean duration of high-flow pulses explained 56% of the variation in recruitment strength. Understanding variation in recruitment dynamics of native mussels and its relationship to river discharge will be useful in designing effective management strategies to enhance conservation of this imperilled fauna.

Minnesota↗

USGS2014

Mortality, movement and behaviour of native mussels during a planned water-level drawdown in the Upper Mississippi River

Managers in the Upper Mississippi River (UMR) are using reductions in the River's water levels during summer to mimic historical water regimes and rehabilitate habitats for vegetation and other species. Concerns for the unintended effects of these actions on mussel populations threatened to halt these projects. Our objective was to characterise the survival and movement of two mussel species in the UMR associated with a water level drawdown. During 2009 (no drawdown) and 2010 (0.3 m summer drawdown), we glued passive integrated transponder tags to 10 Amblema plicata and 10 Lampsilis cardium at each of 11 sites. Five sites were in shallow areas expected to be minimally affected by the drawdown (reference sites), and six sites were in shallow areas expected to be directly affected by the drawdown (treatment sites). About equal numbers of sites within both the reference and treatment areas had low and high slopes. Tagged mussels were randomly allocated across sites (within years). Recovery of tagged mussels was >88% in 2009 and 2010. Mortality was similar and low (mean, c . 5% in both species) among reference sites but was variable and relatively high (means, c . 27% in L. cardium and c . 52% in A. plicata ) among treatment sites; variation in mortality among treatment sites appeared related to slope. The study found evidence of drawdown associations with net horizontal movements in A. plicata but not L. cardium . Weekly horizontal movements in both species were significantly correlated with changes in water elevation. We observed significant slope associations related to the drawdown for mortality and net horizontal movement in A. plicata . There were strong species-specific differences in the effects of the drawdown on mortality, vertical movement and horizontal movement. These results suggest that A. plicata responded to the drawdown by vertical movement into the substratum, whereas L. cardium responded by horizontal movement to deeper water. No directionality of movement was observed in either species. Collectively, these data suggest that drawdowns can influence the mortality, movement and behaviour of mussels in the UMR. However, more information on spatial and temporal distributions of mussels is needed to better understand the magnitude of these effects. Results from this study are being used by resource managers to better evaluate the effects of this management tool on native mussel assemblages.

Minnesota, Wisconsin↗

USGS2012

Patterns in species richness and assemblage structure of native mussels in the Upper Mississippi River

1. To evaluate patterns in mussel assemblages in the Upper Mississippi River (UMR), data from systematic surveys of mussels conducted in three large reaches (Navigation Pools 5, 6, and 18) from 2005–2007 were analysed. 2. Nonmetric multi-dimensional scaling analyses and permutation tests indicated that assemblages differed among reaches. The mussel assemblage in Pool 18 was substantially different from the assemblage in Pool 5 and moderately different from the assemblage in Pool 6, whereas assemblages in Pools 5 and 6 were similar. Assemblages in broadly defined, flowing aquatic habitats did not substantially differ. 3. The dissimilarity of Pool 18 was primarily the result of Pool 18 having higher abundances of three Quadrula species (Q. quadrula, Q. pustulosa, and Q. nodulata), and lower abundances of Amblema plicata and Fusconaia flava. 4. Rarefaction analyses showed that species richness and species density were higher in Pool 18 compared with the other two pools. 5. Large-scale patterns in mussel assemblages may be related to other longitudinal trends in the system including geomorphology, water quality, and abundances of fish species that serve as hosts for glochidial larvae. 6. The results suggest that management goals and actions in the UMR may need to account for important differences in mussel assemblages that occur among reaches.

Illinois, Iowa, Minnesota, Wisconsin↗

USGS2011

Population assessment and potential functional roles of native mussels in the Upper Mississippi River

1. Despite a heightened global concern for native mussels, fundamental research on mussel ecology in large rivers is lacking. These gaps in knowledge about where mussels occur, and why, are limiting habitat restoration activities. 2. Large-scale systematic surveys for native mussels in three reaches of the Upper Mississippi River documented mussel communities composed of 16–23 species and ranging from 2.9–4.5 live mussels m -2 that were actively recruiting new cohorts into their populations (87–100% of the species were found as juveniles 5 years old). Estimates of mean tissue biomass and production in these reaches ranged from 2.1–3.1 g C m -2 and 0.4–0.6 g C m -2 year -1 , respectively. 3. Mussels filtered a significant amount of water (range, 0.05–0.07 m 3 m -2 d -1 ) over a 480 km reach of the Upper Mississippi River — amounting to a filtration rate of 53.1 million m 3 day -1 . The filtration rate of mussels as a percentage of river discharge ranged from 0.5–1.4% at high flows (5% exceedance), from 1.5–4.4% at moderate flows (50% exceedance) and from 4.4–12.2% during low flows (95% exceedance). 4. Collectively, these data suggest that native mussels play an integral role in this ecosystem by sequestering suspended materials that can be used by other benthic organisms.

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗

USGS2006

Ichthyoplankton abundance and variance in a large river system concerns for long-term monitoring

System-wide spatial patterns of ichthyoplankton abundance and variability were assessed in the upper Mississippi and lower Illinois rivers to address the experimental design and statistical confidence in density estimates. Ichthyoplankton was sampled from June to August 1989 in primary milieus (vegetated and non-vegated backwaters and impounded areas, main channels and main channel borders) in three navigation pools (8, 13 and 26) of the upper Mississippi River and in a downstream reach of the Illinois River. Ichthyoplankton densities varied among stations of similar aquatic landscapes (milieus) more than among subsamples within a station. An analysis of sampling effort indicated that the collection of single samples at many stations in a given milieu type is statistically and economically preferable to the collection of multiple subsamples at fewer stations. Cluster analyses also revealed that stations only generally grouped by their preassigned milieu types. Pilot studies such as this can define station groupings and sources of variation beyond an a priori habitat classification. Thus the minimum intensity of sampling required to achieve a desired statistical confidence can be identified before implementing monitoring efforts.

Illinois River, Mississippi River↗

USGS2005

Middle Mississippi River decision support system: user's manual

This user's manual describes the Middle Mississippi River Decision Support System (MMRDSS) and gives detailed examples on its use. The MMRDSS provides a framework to assist decision makers regarding natural resource issues in the Middle Mississippi River floodplain. The MMRDSS is designed to provide users with a spatially explicit tool for tasks, such as inventorying existing knowledge, developing models to investigate the potential effects of management decisions, generating hypotheses to advance scientific understanding, and developing scientifically defensible studies and monitoring. The MMRDSS also includes advanced tools to assist users in evaluating differences in complexity, connectivity, and structure of aquatic habitats among river reaches. The Environmental Systems Research Institute ArcView 3.x platform was used to create and package the data and tools of the MMRDSS.

Techniques and Methods↗

USGS1996

An evaluation of fluorescent elastomer for marking bluegills in experimental studies

We evaluated subdermal injection of a fluorescent elastomer for marking bluegills Lepomis macrochirus in laboratory and pond studies. Marking did not affect the growth or survival of adult or juvenile bluegills. Marks were visible for at least 6 months. This technique is a reliable, relatively inexpensive marking method for the identification of individual fish in experimental studies. Costs of application range from US$0.01 to $0.03 per mark.

Progressive Fish-Culturist↗