Geology topics

Research about Alabama

Source-linked reports with geographic coverage including Alabama.

At least 19 recordsLinked to original sources

USGS2026

Elemental and isotope geochemistry of Smackover Formation brines in Alabama and Arkansas: Implications for fluid mixing and water-rock interaction

This study investigates the geochemical characteristics of brines within the Upper Jurassic Smackover Formation in Alabama and Arkansas through elemental and isotopic analyses and geochemical modeling to reveal the extent and nature of fluid mixing and water-rock interactions. Smackover Formation brines exhibit Na-Cl-Ca hydrogeochemical facies and sulfate depletion relative to seawater. Lower sulfate concentrations, coupled with high H 2 S concentrations in some brines (0-364 mg/L) at temperatures >80°C, suggest that thermochemical sulfate reduction occurred. Cl/Br and Na/Br ratios indicate that salinity was controlled by the mixing of meteoric water with evaporated seawater that had reached halite saturation, rather than by halite dissolution. The δ 18 O and δ 2 H values of the brines also suggest mixing between meteoric water and evaporated seawater that had reached gypsum and halite saturation. Geochemical modeling of seawater evaporation predicts a Cl-Na or Cl-Mg facies after halite saturation, contrasting with the observed Cl-Ca dominance of the Smackover Formation brines. The Ca-enriched brines may have evolved from Cl-Mg-dominated evaporated seawater through dolomitization of limestone. The 87 Sr/ 86 Sr ratios range from 0.70740 to 0.71048, higher than the average of Jurassic seawater (0.707). The non-linear relationship between 87 Sr/ 86 Sr and 1000/Sr suggests alteration of brine geochemistry by fluid mixing or by inputs from Sr and 87 Sr-enriched rock sources. Lithium concentrations are positively correlated with 87 Sr/ 86 Sr ratios and TDS in brines enriched in these constituents. These correlations suggest deeper-seated geogenic sources and have implications for Li exploration in the northern Gulf Coast basin. Normal faults associated with the pre-Jurassic topography may have provided potential pathways for brine migration into the Smackover Formation under the influence of overpressure or thermohaline convection in the Gulf Coast.

Alabama↗

USGS2026

Investigating hydrologic alteration under historical and future scenarios in the Mobile River and Perdido River basins using the cubist algorithm

This study investigates the impacts of human activities and climate variability on hydrologic alterations in the Mobile River and Perdido River Basins of Alabama. The research uses a machine learning approach, specifically cubist models, to quantify and predict changes in flow duration curves (FDCs) under both historical (1980–2009) and future climate scenarios. Future climate projections include the Representative Concentration Pathways (RCP 4.5 and RCP 8.5) and the Shared Socioeconomic Pathways (SSP2 4.5 and SSP5 8.5), evaluated for two future periods: 1980–2069 and 1980–2099. The models incorporate a wide range of covariates, including basin geomorphology, aquifer characteristics, land cover, water storage, environmental factors, solar radiation, census data, and water use data. Under the baseline period (1980–2009), most level 12 hydrologic unit codes (HUC12s) in both basins showed alterations, with substantial differences observed between pre- and post-alteration FDCs. The model performance varied, with a Nash–Sutcliffe Efficiency between 0.91 and 0.95 for testing and between 0.98 and 0.99 for training during the baseline period. Future projections under the RCP 4.5 and RCP 8.5 scenarios generally differed significantly from baseline conditions across all flow regimes ( p < 0.05). In contrast, SSP2 4.5 showed comparatively limited statistical significance, while SSP5 8.5 exhibited significant departures from baseline conditions across all flow regimes, reflecting the greater influence of high-emissions climate forcing on projected hydrologic alterations. Overall, the RCP scenarios projected more widespread statistically significant changes than the corresponding SSP scenarios at the same forcing level, particularly when comparing RCP4.5 with SSP2-4.5, while both RCP8.5 and SSP5-8.5 consistently indicated greater hydrologic alterations than their moderate-emissions counterparts. These findings highlight the importance of considering different flow regimes when assessing the impacts of climate variability on streamflow. This study contributes to the understanding of hydrologic alterations in the Mobile River and Perdido River Basins, providing insights for water resource management and ecological conservation efforts in the region.

Alabama↗

USGS2026

3D Elevation Program—Alabama

Using 3D Elevation Program data, a modern illustration of each State's landscape showcases its elevation differences in vivid detail. Each State has been consistently adjusted and colorized according to its highest and lowest elevations, accentuating differences even in States with low relief. To further emphasize landforms, shaded relief has been added on top of the elevation colors.

Alabama↗

USGS2026

Polychlorinated biphenyl (PCB) exposure assessment of Carolina wren (Thryothorus ludovicianus) and barn swallow (Hirundo rustica) eggs and nestlings collected along Snow Creek and Choccolocco Creek watersheds near Anniston, Alabama, USA

Polychlorinated biphenyls (PCBs) persist for decades when released into the environment and bioaccumulate in aquatic and terrestrial environments, resulting in harmful concentrations of PCBs in fishes, birds, and humans. Approximately 310,000 metric tons of PCBs were produced at a facility in Anniston, Alabama from 1929–1971. Hundreds of metric tons of PCB-contaminated waste were suspected to have been released into local environments. This study was the first systematic exposure assessment of the degree and extent of PCBs and potential co-contaminants—polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, Pb, and Hg—in avian tissues downstream of the Anniston facility. We collected 122 egg and 36 nestling tissue samples from across four exposure areas downstream of the facility and a reference site. A total of seven bird species were collected, but samples were predominantly Carolina wren (resident, Thryothorus ludovicianus ) and barn swallow (migratory, Hirundo rustica ). Concentrations of Pb and Hg in bird tissues collected from the exposure areas were less than toxicity reference values, suggesting Pb or Hg exposures alone were unlikely to affect birds. Total PCB concentrations in avian eggs and nestlings collected from exposure areas were among the greatest ever recorded in birds collected in North America. The PCB congener profiles in this study, paired with results from previous soil and sediment sampling, suggest that PCB-contaminated sediment and soil were the likely source of elevated PCBs in the avian tissues. The PCB concentrations observed in birds downstream of the Anniston facility were at magnitudes that likely affect populations of both resident and migratory birds that utilize the area for foraging and reproduction.

Alabama↗

USGS2026

Spatial behavior of socially isolated wild pigs (Sus scrofa) following sounder removal via trapping

BACKGROUND The rapid expansion of wild pig ( Sus scrofa ) populations across North America, coupled with increased concern over disease transmission, has intensified the need for effective management strategies. Trapping is widely regarded as the most effective control method; however, trapping events often fail to capture entire sounders. The behavioral responses of untrapped individuals following partial sounder removal remain poorly understood, potentially undermining management efficiency. We evaluated the spatiotemporal movement responses of wild pigs that became socially isolated following trapping events. RESULTS We deployed GPS collars on 18 female wild pigs from multiple sounders and quantified post-trapping movement patterns using distance from trap site, step length, persistence velocity, space covered and overlap area over a 30-day period. Movement responses were highly variable among individuals, but wild pigs travelled an average of 1.2 km from the trap, with a maximum observed distance of 6.37 km. Space-use overlap was limited, and range sizes remained relatively stable. Individuals originating from sounders with a greater proportion of females moved farther from the trap, whereas wild pigs in better body condition exhibited lower movement velocities. CONCLUSION Socially isolated wild pigs generally remained close to trap sites following partial sounder removal and rarely dispersed from the area. This behavioral pattern suggests a predictable post-trapping window during which untrapped individuals remain spatially accessible. These findings provide critical empirical support for adaptive trapping strategies, indicating that follow-up removal efforts can be effectively concentrated near original trap locations to improve management efficiency and reduce the risk of population persistence or disease spread. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Alabama↗

USGS2026

Contrasting haemosporidian infections in two ecologically distinct wading birds from breeding colonies in the southeastern United States

Wading birds may serve as ideal hosts for avian hemoparasites, as they are long-lived, undertake extensive movements, form dense breeding colonies, and inhabit water-associated environments that support vectors. Although previous studies have reported parasite species and prevalence in various wading bird species, little is known about their associations with bird behavior and life stage. To address this gap, we examined haemosporidian infections in two ecologically distinct species, white ibis ( Eudocimus albus ) and tricolored heron ( Egretta tricolor ), to explore differences in life stage and movement that may explain prevalence differences. We combined blood screening for hemoparasites with satellite tracking data describing birds’ movement patterns. We screened 95 white ibis (67 juveniles and 28 adults or subadults) and 69 tricolored herons (45 juveniles and 24 adults). We detected a single Haemoproteus plataleae lineage in both species, with higher infection prevalence in white ibis (42.1 %) than in tricolored herons (14.5 %). Among white ibis, adults showed a higher prevalence (67.9 %) than juveniles (31.3 %), whereas in tricolored herons, adults had a prevalence of 8.3 % and juveniles 17.8 %. Non-breeding season movement data showed that white ibis used both freshwater and saline habitats across the southeastern United States, which may also serve as habitats for vectors. In contrast, tricolored herons remained mainly along coastal areas, using saline habitats in the southeastern United States and wintering sites in Central America, which may be less favorable for vectors. Overall, white ibis may serve as major reservoirs and sources of reinfection for H. plataleae , whereas tricolored herons may facilitate parasite dispersal between breeding colonies along the coasts of the southeastern United States and wintering areas in Central America. This study presents the first direct comparison of hemoparasite infections in two ecologically distinct wading birds and highlights movement data as key to explaining infection differences, providing a baseline for future studies.

Alabama↗

USGS2026

Spatio-temporal modeling for assessing geoenergy resources: A workflow applied to gas in place variation in coal beds

The ability to estimate spatio-temporal changes in hydrocarbon reservoir properties and energy resources within pore volumes is essential for optimizing production, reservoir management, geologic energy storage, and safety in underground mining operations. In coal seams, predicting remaining methane gas-in-place (GIP) is critical for quantifying producible gas and improving mine safety and productivity through effective ventilation planning. Although such changes are commonly evaluated using physics-based numerical simulation models, these approaches often require extensive data, calibration effort, and time. This study presents a spatio-temporal geostatistical modeling approach that bridges the gap between purely spatial models and full numerical simulations. The method is applied to a case study of coal seam degasification in the Mary Lee coal group, Black Warrior Basin, Alabama, USA, to estimate GIP evolution over time within a selected mining district. The analysis uses published data from prior natural gas production history-matching of degasification using vertical wells. Empirical spatial and temporal statistics were calculated for reservoir pressure and water saturation, and spatio-temporal variogram models were fitted to experimental variograms. These models provided the structural basis for spatio-temporal kriging, integrated with spatial estimates of time-invariant parameters (porosity, density, and thickness) to estimate GIP. This approach enabled estimation of GIP changes over time, including periods without data. Boxplots of GIP estimates indicated systematic depletion and decreasing spatial variability, reflecting the impacts of degasification. Comparison with cumulative gas production from empirical well records showed approximately 85% agreement based on a relative similarity metric. Spatio-temporal GIP estimates were also used to estimate methane emissions to longwall ventilation systems and compared with reported emissions from the U.S. EPA Greenhouse Gas Reporting Program, showing similar distributions (≈80%) given data limitations. Overall, this integrated modeling approach provides time-dependent GIP estimates with broader implications for resource assessment applications.

Alabama↗

USGS2025

Streamflow as a stressor: Disentangling hydrology and water quality impacts to characterize flow-ecology relationships for two stream assemblages across two southeastern landscapes

Disassociating the independent effects of flow and water quality on the ecology of flowing waters is an overarching goal in water resource science needed to improve the efficacy of watershed management. However, the interrelatedness of these gradients and their subsequent alteration due to land use change has constrained progress made on this front. The objective of this study was to use benthic macroinvertebrate and fish assemblage data to characterize flow-ecology relationships that were unchanged by water quality impacts across two southeastern landscapes in the USA to help detect ecological change driven by flow alteration. General linear latent models were used to identify taxa that were responsive to high or low flow metrics and water quality gradients. Bayesian hierarchical generalized additive models were then developed using these indicator taxa and three biological metrics to identify flow-specific relationships that were unaffected by water quality impacts. Three low flow-specific relationships were identified, illustrating how potential agricultural or urban impacts to hydrology reduced stream biological health. Importantly, flow-ecology relationships developed using indicator taxa in this study effectively captured hydrology-specific impacts while biological metrics typical of state monitoring and assessment programs did not. Therefore, developing flow-specific biological metrics is a critical step when developing management strategies targeting flow alteration. Implementing standardized frameworks such as the one characterized here can limit contradictory findings and improve streamflow enhancement and restoration project efficacy. These low flow-specific relationships will enhance managers' capacity to develop environmental flow standards, monitor their success, and better understand urban and agricultural impacts on stream assemblages.

Alabama↗

USGS2025

Modeling seawater intrusion along the Alabama coastline using physical and machine learning models to evaluate the effects of multiscale natural and anthropogenic stresses

Seawater intrusion threatens groundwater resources in coastal regions, including southern Baldwin County, Alabama, where the freshwater-saltwater interface dynamics remain poorly understood. To address this gap, this study uses combined physics-based and machine-learning models to quantify seawater intrusion caused by natural (storm surges) and anthropogenic (human activities) perturbations. The long short-term memory network and wavelet analysis were used to assess vertical aquifer vulnerabilities, revealing that the shallow part of the Coastal lowlands aquifer system (CL1) in the southern Baldwin County region is more susceptible to sea level rise and groundwater extraction than deeper aquifers. Based on these findings, a cross-sectional numerical model (physics approach) for the CL1 aquifer was developed to evaluate tidal and storm surge effects, using Tropical Storm Claudette (June 2021) as a case study. Results showed that tidal fluctuations had a minimal impact on the saltwater-freshwater interface location, whereas storm surges caused substantial inland movement, with effects lasting for nine months. The steady-state version of the three-dimensional (3D) physical model predicted seawater intrusion across the entire area, and convolutional neural network-based modeling further validated the model results. The 3D physical model was also applied to a smaller area to assess human impact on the saltwater interface due to two groundwater pumping scenarios (± 50% of the baseline pumping rate). Results revealed that a 50% increase in groundwater withdrawals caused seawater to advance ~ 320 m inland, whereas a 50% reduction led to a ~ 270-meter retreat. This study highlights the vulnerability of Alabama’s shallow coastal aquifers to seawater intrusion due to storm surges and human activities, and demonstrates that combining physics-based models with machine learning approaches can improve groundwater predictions, though its accuracy depends on the availability of site-specific data.

Alabama↗

USGS2025

Analyzing multi-year nitrate concentration evolution in Alabama aquatic systems using a machine learning model

Rising nitrate contamination in water systems poses significant risks to public health and ecosystem stability, necessitating advanced modeling to understand nitrate dynamics more accurately. This study applies the long short-term memory (LSTM) modeling to investigate the hydrologic and environmental factors influencing nitrate concentration dynamics in rivers and aquifers across the state of Alabama in the southeast of the United States. By integrating dynamic data such as streamflow and groundwater levels with static catchment attributes, the machine learning model identifies primary drivers of nitrate fluctuations, offering detailed insights into the complex interactions affecting multi-year nitrate concentrations in natural aquatic systems. In addition, a novel LSTM-based approach utilizes synthetic surface water nitrate data to predict groundwater nitrate levels, helping to address monitoring gaps in aquifers connected to these rivers. This method reveals potential correlations between surface water and groundwater nitrate dynamics, which is particularly meaningful given the lack of water quality observations in many aquifers. Field applications further show that, while the LSTM model effectively captures seasonal trends, limitations in representing extreme nitrate events suggest areas for further refinement. These findings contribute to data-driven water quality management, enhancing understanding of nitrate behavior in interconnected water systems.

Alabama↗

USGS2025

Modeling the impacts of sand placement strategies on barrier island evolution in a semi-enclosed bay system

This study assesses the impacts of five proposed restoration actions at Little Dauphin Island, a low-lying relic spit in a semi-enclosed bay system on the Alabama coast. A Delft3D model is developed to simulate annual scale (five-year) sediment transport and resulting bed level changes. The model is validated with observed water level and wave data, as well as sediment tracers that were deployed offshore of the island. An XBeach model is developed to simulate storm-driven morphologic change and is validated for hurricanes Ivan (2004), Katrina (2005)and Sally (2020). Together, the models are used to assess differences in the island's morphological response under a no-action (status quo) scenario representing a continuous island, tidal inlet realignment, a sand motor nourishment, beach and dune restoration and a dredged offshore borrow area. The no-action scenario revealed that the island breached at multiple locations including the location of the proposed inlet realignment during each storm. The realigned channel did not prevent breaching on the island, but reduced the magnitude of sand transported through the breaches. The sand motor provided some sheltering to leeward shorelines during storms but did not prevent breaching from occurring elsewhere. Fairweather waves and currents were not strong enough to transport sand outside of the vicinity of the feature to feed adjacent shorelines as intended. The beach and dune restoration reduced storm-driven overtopping along the nourished shoreline. For habitat purposes, strategically placed bayous provided low elevation points that allowed overwash depending on the direction of cross-barrier water level gradients.

Alabama↗

USGS2024

Sensitivity of Alabama freshwater gastropod species to nickel exposure

Snails are effective bioindicators due to their prolific distribution, high level of endemism, and capacity to accumulate contaminants. Freshwater snails have unique ecological niches which are imperiled by land‐use change and the introduction of hazardous chemicals. To assess how environmental alterations affect gastropods, lab‐based studies are needed to characterize the toxicity of specific stressors. This can help guide policy decisions and remediation efforts. The aim of this research was to characterize acute toxicity of nickel (Ni) on endemic snails ( Somatogyrus georgianus [Walker, 1904], Elimia cahawbensis [Lea, 1861], and Elimia spp.) and measure the accumulation of Ni and mineral elements including calcium (Ca), magnesium, potassium, and sodium (Na). Snails were exposed to six concentrations (25–800 µg/L) of Ni for 96 h. Among the studied snail species, E. cahawbensis was the most sensitive to Ni, with the lowest lethal concentration where 50% of the organisms died (LC50) at 88.88 µg/L Ni after 96 h. The LC50 at 96 h for S. georgianus was 167.78 µg/L Ni, and 393.13 μg/L Ni for Elimia spp. Except for Elimia spp., mortality of the other two snail species corresponded to the whole‐body uptake of Ni. Nickel exposure also influenced Ca and Na uptake for Elimia spp. All three endemic species are potential candidate species for evaluating localized effects of human activities, and the present study provides a first step in characterizing how snails would be affected by environmental alterations. More research could further characterize potential effects of other human stressors on these endemic snail species. Future research into subindividual responses and routes of exposure can further elucidate variations in species sensitivity.

Alabama↗

USGS2024

Model sensitivity analysis for coastal morphodynamics: Investigating sediment parameters and bed composition in Delft3D

Numerical simulation of sediment transport and subsequent morphological evolution rely on accurate parameterizations of sediment characteristics. However, these data are often not available or are spatially and/or temporally limited. This study approaches the problem of limited sediment grain-size data with a series of simulations assessing model sensitivity to sediment parameters and initial bed composition configurations in Delft3D, leading to improved modeling practices. A previously validated Delft3D sediment transport and morphology model for Dauphin Island, Alabama, USA, is used as the benchmark case. A method for the generation of representative sediment grain sizes and their spatially varying distributions is presented via end-member analysis of in situ surficial sediment samples. Derived sediment classes and their spatial distributions are applied to two sensitivity case simulations with increasing bed composition complexity. First, multiple sediment classes are applied in a single fully mixed layer, regardless of sediment type. Second, multiple sediment classes are applied in a thin, fully mixed transport layer with underlayers containing only the non-cohesive sediment classes below. Simulations were carried out in a probabilistic, Delft3D MorMerge configuration to capture long-term morphology change for 10 years. We found there is sensitivity to the inclusion of additional sediment classes and sediment distribution made evident in bed level and morphology change. Inclusion of highly mobile fine sediments altered model results in each sensitivity case. The model was also found to be sensitive to initial bed composition in terms of bed level and morphology change, with notable differences between sensitivity cases on decadal timescales, indicating an armoring effect in the second sensitivity case, which used the transport and underlayer bed configuration. The results of this study offer guidance for numerical modelers concerned with sediment behavior in coastal and estuarine environments.

Alabama↗

USGS2024

Pesticide occurrence in shallow groundwater in three regions of agricultural land use: Baldwin County, the Wiregrass region, and the Tennessee River valley region of Alabama, 2009–20

As part of a cooperative investigation between the U.S. Geological Survey and the Alabama Department of Agriculture and Industries, a network of 22 groundwater wells were sampled from 2014 through 2020 for about 230 pesticide and pesticide degradate compounds. Wells were located in three regions of intensive agricultural land use in Alabama: Baldwin County, the Wiregrass region, and the Tennessee River valley region. Metolachlor sulfonic acid, a degradate of the herbicide metolachlor, was the most frequently detected compound, occurring in about 70 percent of the samples. Three other compounds, metolachlor, atrazine, and 2-chloro-4-isopropylamino-6-amino-s-triazine, were also detected in more than half of the samples. Metolachlor and its degradates accounted for 33 of the 50 greatest compound concentrations study-wide, including the maximum pesticide concentration across all compounds (62,500 nanograms per liter). The frequency and magnitude of detections of many specific pesticide compounds varied among the three regions, but all detected pesticide concentrations were well below the U.S. Environmental Protection Agency maximum contaminant levels and applicable human health benchmarks. Sample results were combined with results of previous (2009–13) sampling to provide a continuous time-series of data for 2009–20. More than half of the 289 pesticide compounds analyzed during 2009–20 were not detected in any samples. Only four compounds were detected at great enough frequency throughout the 10 sampling years to evaluate patterns of change through time. Metolachlor and its degradate, metolachlor sulfonic acid, were frequently detected in all regions. Atrazine and its degradate, 2-chloro-4-isopropylamino-6-amino-s-triazine, were also detected in wells from all regions, but the variability and magnitude of concentrations were greatest in the Tennessee River valley region. No apparent temporal pattern in concentrations was found.

Alabama↗

USGS2024

Cross section N–N' through the Valley and Ridge province of the southern Appalachian basin, from Greene County, west-central Alabama, to Bibb County, central Alabama

Introduction Geologic cross section N–N′ is the sixth in a series of geologic cross sections constructed by the U.S. Geological Survey to document and improve understanding of the geologic framework and petroleum systems of the Appalachian basin. Cross section N–N′ provides a regional view of the structural and stratigraphic framework of the Appalachian basin in the Valley and Ridge province in western and central Alabama; it spans approximately 69 miles (mi) (111 kilometers [km]). This geologic cross section is a companion to geologic cross sections E–E′ , D–D′ , C–C′ , I–I′ , and A–A′ that are located approximately 350 to 550 mi (563 to 885 km) to the northeast. Cross section N–N' complements earlier geologic cross sections through the Alabama part of the Appalachian basin. Although some of the other cross sections show more structural and stratigraphic detail, they are of more limited extent geographically and stratigraphically. Cross section N–N′ contains information that is useful for evaluating energy resources in the Appalachian basin. Although the Appalachian basin petroleum systems are not shown on the cross section, many of their key elements (such as source rocks, reservoir rocks, seals, and traps) can be inferred from lithologic units, unconformities, and geologic structures shown on the cross section. Other aspects of petroleum systems (such as the timing of petroleum generation and petroleum migration pathways) may be evaluated by burial history, thermal history, and fluid flow models based on what is shown on the cross section. In addition, cross section N–N′ may be used as a reconnaissance tool to identify plausible geologic structures and strata for the subsurface storage of liquid waste or for the sequestration of carbon dioxide.

Alabama↗

USGS2024

Assessing the attractiveness of native wildflower species to bees (Hymenoptera: Anthophila) in the southeastern United States

Habitat loss, agricultural intensification, pesticide use, disease and climate change have contributed to the decline of numerous insect groups. Recent government initiatives have recognized the importance of supplementary wildflower plantings to support native bee populations, yet little information exists on the attractiveness of recommended plant species to bees. With the use of network analysis and generalized linear mixed models, we evaluated the attractiveness of 18 wildflower species belonging to 6 families (Apiaceae, Apocynaceae, Asteraceae, Fabaceae, Lamiaceae and Verbenaceae) planted in a randomized block design by conducting timed targeted sweep netting surveys. We also evaluated the floral preferences of four bee species ( Apis mellifera , Halictus poeyi/ligatus , Bombus griseocollis and Bombus impatiens ) to the planted wildflower species with the use of GLMs. We found that Asclepias tuberosa, Gaillardia pulchella and Verbena hastata attracted the greatest abundance, richness and diversity of native bees compared to the other wildflower species. Collectively, Asclepias tuberosa, Gaillardia pulchella and Verbena hastata attracted 89% of all bee taxa in the study, which exemplifies the importance of including them in a wildflower mixture to attract native bees. While several wildflower species attracted low abundance, richness and diversity of native bees such as Monarda fistulosa, Symphyotrichum pilosum and Eryngium yuccifolium , they are still ecologically important for attracting uncommon or specialist bee species and should be included in seed mixes for this reason. Solution . Our results highlight that each species of native wildflower varies in the abundance, richness and diversity of native bees they attract; this could be considered in the decision-making of landowners and land managers to promote wildflower plantings to reflect the needs of certain groups of bees of conservation interest.

Alabama↗

USGS2023

Evaluation of shoreline rotenone application to control Largemouth Bass recruitment in small impoundments

Objective Reducing Largemouth Bass Micropterus salmoides recruitment and therefore population density could benefit recreational fisheries in small impoundments by improving individual growth rates and increasing the average size and condition of Largemouth Bass. To achieve these effects, methods of controlling Largemouth Bass recruitment should avoid reducing the productivity of their primary prey species, the Bluegill Lepomis macrochirus . Methods We tested this hypothesis by evaluating the effects of shoreline rotenone application on the density of Bluegill and the density, growth, and survival of age-0 and age-1 Largemouth Bass in 15 Alabama small impoundments. Result After treatment, Largemouth Bass age-0 densities declined and mean age-1 length increased, whereas Bluegill populations were not significantly reduced. Conclusion Our study indicates that shoreline rotenone application may be a valuable method for reducing Largemouth Bass recruitment and increasing the growth of age-1 Largemouth Bass in small impoundments. However, further research is needed to understand the effects of treatment on nontarget fishes and to better assess the effects of factors such as impoundment surface area and treatment frequency and duration on the ultimate utility of the approach.

Alabama↗

USGS2023

Models for linking hunter retention and recruitment to regulations and game populations

Introduction: Declining hunter populations across North America present wildlife management agencies with the prospect of declining revenues for wildlife conservation and management and the need for new tools to evaluate management strategies and predict future status of game species and hunters. Methods: Here we present a modeling framework and potential decision support tool for managers to link future hunter population dynamics to regulatory restrictiveness, prey abundance, and harvest success. Our hunter model is parameterized based on the authors’ judgment and can be used for demonstration purposes. We simulated three scenarios of restricted harvest, moderate harvest and liberal harvest. Results: Our simulations show that even though liberal harvest predicts higher cumulative license sales revenue, it corresponds with a slight decline in buck abundance over 10 years. In contrast, highly restrictive harvest corresponds with deer population growth, but a near collapse of hunter populations. Our model demonstrates that managers might face tradeoffs between managing for deer population abundance and hunting revenue and clarifies how these factors might affect decision making. Discussion: The utility of our tool would be dependent on accessing data on hunter retention and recruitment, however, the strength of our paper is in highlighting a new way of thinking about and potentially addressing these potential tradeoffs. Further, these simulations demonstrate that these tools could be used to evaluate management strategies but also highlight uncertainties, establish research priorities, and potentially design an adaptive management framework.

Alabama↗