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USGS2020

Wildfire and the ecological niche: Diminishing habitat suitability for an indicator species within semi‐arid ecosystems

Globally accelerating frequency and extent of wildfire threatens the persistence of specialist wildlife species through direct loss of habitat and indirect facilitation of exotic invasive species. Habitat specialists may be especially prone to rapidly changing environmental conditions because their ability to adapt lags behind the rate of habitat alteration. As a result, these populations may become increasingly susceptible to ecological traps by returning to suboptimal breeding habitats that were dramatically altered by disturbance. We demonstrate a multistage modeling approach that integrates habitat selection and survival during the key nesting life‐stage of a bird species of high conservation concern, the greater sage‐grouse ( Centrocercus urophasianus ; hereafter, sage‐grouse). We applied these spatially explicit models to a spatiotemporally robust dataset of sage‐grouse nest locations and fates across wildfire‐altered sagebrush ecosystems of the Great Basin ecoregion, western United States. Female sage‐grouse exhibited intricate habitat selection patterns that varied across regional gradients of ecological productivity among sagebrush communities, but often selected nest sites that disproportionately resulted in nest failure. For example, 23% of nests occurred in wildfire‐affected habitats characterized by reduced sagebrush cover and greater composition of invasive annual grasses. We found survival of nests was negatively associated with wildfire‐affected areas, but positively associated with higher elevations with increased ruggedness and overall shrub cover. Strong site fidelity likely drove sage‐grouse to continue nesting in habitats degraded by wildfire. Hence, increasing frequency and extent of wildfire may contribute disproportionately to reduced reproductive success by creating ecological traps that act as population sinks. Identifying such habitat mismatches between selection and survival facilitates deeper understanding of the mechanisms driving reduced geographic niche space and population decline at broad spatiotemporal scales, while guiding management actions to areas that would be most beneficial to the species.

Global Change Biology↗

USGS2014

Land use and climate affect Black Tern, Northern Harrier, and Marsh Wren abundance in the Prairie Pothole Region of the United States

Bird populations are influenced by many environmental factors at both large and small scales. Our study evaluated the influences of regional climate and land-use variables on the Northern Harrier (Circus cyaneus), Black Tern (Childonias niger), and Marsh Wren (Cistothorus palustris) in the prairie potholes of the upper Midwest of the United States. These species were chosen because their diverse habitat preference represent the spectrum of habitat conditions present in the Prairie Potholes, ranging from open prairies to dense cattail marshes. We evaluated land-use covariates at three logarithmic spatial scales (1,000 ha, 10,000 ha, and 100,000 ha) and constructed models a priori using information from published habitat associations and climatic influences. The strongest influences on the abundance of each of the three species were the percentage of wetland area across all three spatial scales and precipitation in the year preceding that when bird surveys were conducted. Even among scales ranging over three orders of magnitude the influence of spatial scale was small, as models with the same variables expressed at different scales were often in the best model subset. Examination of the effects of large-scale environmental variables on wetland birds elucidated relationships overlooked in many smaller-scale studies, such as the influences of climate and habitat variables at landscape scales. Given the spatial variation in the abundance of our focal species within the prairie potholes, our model predictions are especially useful for targeting locations, such as northeastern South Dakota and central North Dakota, where management and conservation efforts would be optimally beneficial. This modeling approach can also be applied to other species and geographic areas to focus landscape conservation efforts and subsequent small-scale studies, especially in constrained economic climates.

Iowa;Minnesota;Montana;Nebraska;North Dakota;South↗

USGS2015

Dreissenid mussel research priorities workshop

Currently, dreissenid mussels have yet to be detected in the northwestern part of the United States and western Canada. Infestation of one of the jurisdictions within the mussel-free Pacific Northwest would likely have significant economic, societal and environmental implications for the entire region. Understanding the biology and environmental tolerances of dreissenid mussels, and effectiveness of various management strategies, is key to prevention. On November 4-5, 2015, the Aquatic Bioinvasion Research and Policy Institute and the Center for Lakes and Reservoirs at Portland State University, the US Geological Survey, and the Pacific States Marine Fisheries Commission, convened a Dreissenid Mussel Research Priorities Workshop funded by the Great Northern Landscape Conservation Cooperative. The purpose of the workshop was to review dreissenid research priorities in the 2010 Quagga-Zebra Mussel Action Plan for Western U.S. Waters, reassess those priorities, incorporate new information and emerging trends, and develop priorities to strategically focus research efforts on zebra and quagga mussels in the Pacific Northwest and ensure that future research is focused on the highest priorities. It is important to note that there is some repetition among dreissenid research priority categories (e.g., prevention, detection, control, monitoring, and biology). Workshop participants with research experience in dreissenid mussel biology and management were identified by a literature review. State and federal agency managers were also invited to the workshop to ensure relevancy and practicality of the workshop outcomes. A total of 28 experts (see sidebar) in mussel biology, ecology, and management attended the workshop.

Conference Paper↗

USGS2016

Predictive mapping of seabirds, pinnipeds and cetaceans off the Pacific Coast of Washington

About this report This report supports Washington-led marine spatial planning and responsible stewardship of natural and cultural resources by the Olympic Coast National Marine Sanctuary. Washington state agencies and the sanctuary continually seek the best available science to improve management of marine uses and stewardship of resources (Etheridge et al., 2010; Washington Department of Fish and Wildlife, 2015a). This report and associated data provide new, state- and sanctuary-requested information on seabird, pinniped, and cetacean distributions. Through spatial planning, information on species distributions can help to identify high-value conservation areas, minimize adverse effects of ocean uses and mitigate impacts of coastal hazards. Correspondingly, the Washington Department of Fish and Wildlife has already begun to use the maps of predicted relative density presented in this report to identify ecologically important areas off the Pacific Coast of Washington and apply this information to plan for offshore renewable energy development. This is the culmination of three years of work to compile information on seabirds, pinnipeds, and cetaceans, and advance a modeling framework that can integrate data sets and develop accurate predictions of relative density for important species off the Pacific Coast of Washington. Previous reports, which evaluated existing datasets of at-sea observations (Menza et al., 2014; Kracker and Menza, 2015) and presented superseded versions of seabird models (Menza et al., 2015), provided base information for this report. In addition to the maps in this published report, all new seabird, pinniped and cetacean predictions will be made publicly available as digital geospatial data through the National Centers for Environmental Information. This research supports the National Oceanic and Atmospheric Administration (NOAA) Coastal Zone Management Program, a voluntary partnership between the federal government and U.S. coastal and Great Lakes states and territories authorized by the Coastal Zone Management Act (CZMA) of 1972 to address national coastal issues. The act provides the basis for protecting, restoring, and responsibly developing our nation’s diverse coastal communities and resources. To meet the goals of the CZMA, the national program takes a comprehensive approach to coastal resource management – balancing the often competing and occasionally conflicting demands of coastal resource use, economic development, and conservation. A wide range of issues are addressed through the program, including coastal development, water quality, public access, habitat protection, energy facility siting, ocean governance and planning, coastal hazards, and climate change. Accurate maps of seabird and marine mammal distributions are an important tool for making informed management decisions that affect all of these issues.

Washington↗

USGS2020

Gene transcript profiling in desert bighorn sheep

Respiratory disease is a key factor affecting the conservation and recovery of bighorn sheep ( Ovis canadensis ) populations. Innovative, minimally invasive tools such as gene transcription–based diagnostics have the potential to improve our understanding of the broad range of factors that can affect the health of wild sheep. Evaluation of transcript levels for genes representative of multiple internal systems enables measurement of physiological responses of individuals as well as populations to environmental stressors such as pathogens, nutritional deficiency, or contaminants. We developed real‐time polymerase chain reaction assays for 14 genes of interest representing systems including inflammation, cell signaling, detoxification, antiviral, antibacterial, or general stress. Initial results from desert bighorn sheep ( O. c. nelsoni ) sampled from the River, Muddy, and Bare mountains as well as from the Pintwater Range, in southern Nevada, USA, indicated unique transcript profiles associated with each population. This initial study provides the framework from which controlled variable or longitudinal studies can be made, thus augmenting the potential to inform management actions in the future.

Nevada↗

USGS2000

Manatee mortality in Puerto Rico

The most pressing problem in the effective management of the West Indian manatee (Trichechus manatus) in Puerto Rico is mortality due to human activities. We assessed 90 cases of manatee strandings in Puerto Rico based on historical data and a coordinated carcass salvage effort from 1990 through 1995. We determined patterns of mortality, including type of event, condition of carcasses, spatial and temporal distribution, gender, size/age class, and the cause of death. The spatial distribution of stranding events was not uniform, with the north, northeast, and south coasts having the highest numbers. Six clusters representing the highest incidence included the areas of Fajardo and Ceiba, Bahia de Jobos, Toa Baja, Guayanilla, Cabo Rojo, and Rio Grande to Luquillo. The number of reported cases has increased at an average rate of 9.6%/yr since 1990. The seasonality of stranding events showed a bimodal pattern, from February through April and in August and September. Most identified causes of death were due to human interaction, especially captures and watercraft collisions. Natural causes usually involved dependent calves. From 1990 through 1995, most deaths were attributed to watercraft collisions. A reduction in anthropogenic mortality of this endangered species can be accomplished only through education and a proactive management and conservation plan that includes law enforcement, mortality assessment, scientific research, rescue and rehabilitation, and inter- and intraagency cooperation.

Environmental Management↗

USGS2016

Using a full annual cycle model to evaluate long-term population viability of the conservation-reliant Kirtland's warbler after successful recovery

Long-term management planning for conservation-reliant migratory songbirds is particularly challenging because habitat quality in different stages and geographic locations of the annual cycle can have direct and carry-over effects that influence the population dynamics. The Neotropical migratory songbird Kirtland's warbler Setophaga kirtlandii (Baird 1852) is listed as endangered under the U.S. Endangered Species Act and Near Threatened under the IUCN Red List. This conservation-reliant species is being considered for U.S. federal delisting because the species has surpassed the designated 1000 breeding pairs recovery threshold since 2001. To help inform the delisting decision and long-term management efforts, we developed a population simulation model for the Kirtland's warbler that incorporated both breeding and wintering grounds habitat dynamics, and projected population viability based on current environmental conditions and potential future management scenarios. Future management scenarios included the continuation of current management conditions, reduced productivity and carrying capacity due to the changes in habitat suitability from the creation of experimental jack pine Pinus banksiana (Lamb.) plantations, and reduced productivity from alteration of the brown-headed cowbird Molothrus ater (Boddaert 1783) removal programme. Linking wintering grounds precipitation to productivity improved the accuracy of the model for replicating past observed population dynamics. Our future simulations indicate that the Kirtland's warbler population is stable under two potential future management scenarios: (i) continuation of current management practices and (ii) spatially restricting cowbird removal to the core breeding area, assuming that cowbirds reduce productivity in the remaining patches by ≤41%. The additional future management scenarios we assessed resulted in population declines. Synthesis and applications . Our study indicates that the Kirtland's warbler population is stable under current management conditions and that the jack pine plantation and cowbird removal programmes continue to be necessary for the long-term persistence of the species. This study represents one of the first attempts to incorporate full annual cycle dynamics into a population viability analysis for a migratory bird, and our results indicate that incorporating wintering grounds dynamics improved the model performance.

Michigan↗

USGS2005

The fishes of George Washington Carver National Monument, Missouri, 2003

Fish were collected at six sites at George Washington Carver National Monument by seining and electrofishing during a base-flow period on July 17-18, 2003. Approximately 700 fish were collected and identified at the six sampling sites. Those individuals represented 17 species (and 1 hybrid) and 13 genera. The number of species collected at the five stream sites ranged from 9 to 12; a hybrid sunfish and 4 species were collected from a pond. Fish collected at stream sites were typical of small headwater streams and no species collected in this study are federally-listed threatened or endangered species. The three most common species were the southern redbelly dace, central stoneroller, and green sunfish. Some differences existed between the assemblages (groups of species) collected in 2003 and in the previous inventories. Four of the 17 fish species collected in this inventory previously had not been collected at the monument. However, 11 species collected in one or more of the previous inventories were not collected in this effort. There is no indication that a change in environmental conditions is responsible for the absence of these species; more likely reasons are seasonal variability, extirpation, low population density, and misidentification. Four species collected at George Washington Carver National Monument may be of special interest to National Park Service managers and others. The cardinal shiner and stippled darter are endemic to the Ozark Plateaus. The Arkansas darter is considered a species of conservation concern by the State of Missouri. The grass carp is an introduced species.

Scientific Investigations Report↗

USGS2020

Linking monitoring and data analysis to predictions and decisions for the range-wide eastern black rail status assessment

The US Fish and Wildlife Service has initiated a re-envisioned approach for providing decision makers with the best available science and synthesis of that information, called the Species Status Assessment (SSA), for endangered species decision making. The SSA report is a descriptive document that provides decision makers with an assessment of a species’ current status and predicted future status. These analyses support all manner of decisions under the US Endangered Species Act, such as listing, reclassification, recovery planning, etc. Novel scientific analysis and predictive modeling in SSAs could be an important part of rooting species conservation decisions in current data and cutting edge analytical and modeling techniques. Here we describe a novel analysis of available data to assess current condition of eastern black rail across its range in a dynamic occupancy analysis. We used the results of the analysis to develop a site occupancy projection model where the model parameters (initial occupancy, site persistence, colonization) were linked to environmental covariates, such as land management and land cover change (sea-level rise, development, etc.). We used the projection model to predict future conditions under multiple sea-level rise and habitat management scenarios. Occupancy probability and site colonization were low in all analysis units and site persistence was also low, suggesting low resiliency and redundancy currently. Extinction probability was high for all analysis units in all simulated scenarios except one with significant effort to preserve existing habitat, suggesting low future resiliency and redundancy. With results of these data analyses and predictive modeling, the US Fish and Wildlife Service concluded that protections of the Endangered Species Act were warranted for this subspecies.

Endangered Species Research↗

USGS2016

Iterative ecological forecasting: Needs, opportunities, and challenges

A fundamental environmental challenge facing humanity in the 21st century and beyond is predicting the impacts of global environmental change. This challenge is complicated by the fact that we live on a non-stationary, unreplicated planet that is rapidly moving outside the envelope of natural variability into an historical non-analog world. In other words, while the past helps inform us about how the world has worked, it may no longer be the relevant frame of reference for management, conservation, and sustainability. In this future world the two questions at the foundation of sustainability are “How are ecosystems and the services they provide going to change in the future?” and “How do human decisions affect this trajectory?” These are, at their heart, questions about ecological forecasting.

Conference Paper↗

USGS1993

1993 Annual Report: San Francisco estuary regional monitoring program for trace substances

This first annual report of the San Francisco Estuary Regional Monitoring Program contains the results of monitoring measurements made in 1993. Measurements of conventional water quality parameters and trace contaminant concentrations were made at 16 stations throughout the Estuary three times during the year: the wet period (March), during declining Delta outflow (May), and during the dry period (September). Water toxicity tests were conducted at 8 of those stations. Measurements of sediment quality and contaminant concentrations were made at the same 16 stations during the wet and dry sampling periods. Sediment toxicity was measured at 8 of those stations. Transplanted, bagged bivalve bioaccumulation and condition was measured at 11 stations during the wet and dry sampling periods. Water Monitoring. Total or near-total (dissolved + particulate, see text) arsenic, cadmium, selenium, and dissolved (0.45 µm filtered) arsenic, cadmium, copper, nickel, silver, and zinc in water were highest in the South Bay. In general, dissolved metals in water were usually lowest in the Central Bay due to ocean influences. Near-total nickel and total mercury in water were highest in the northern estuary (San Pablo and Suisun Bays). Dissolved chromium and lead were highest at the Sacramento and San Joaquin River confluence stations. Six of the ten dissolved trace metals were highest in March during high runoff. Dissolved and total arsenic, selenium, and near-total cadmium were highest in September. Concentrations of trace organic contaminants are reported for the March sampling period. Total PAHs and PCBs were highest in the South Bay, but PCBs were also high in the Napa River. Dissolved PAHs were highest in the Central Bay, and dissolved PCBs were highest in the Napa River. Total and dissolved pesticides were highest in the Sacramento River and in the Extreme South Bay. Concentrations of trace elements in water (except selenium) were usually closely related with other environmental parameters. Total or near-total metals concentrations in water were most often associated with the amount of particulate material (TSS) in the water. Dissolved concentrations were usually associated with salinity or dissolved organic carbon (DOC) content. Dissolved PAHs were well correlated with TSS, but dissolved and total trace organic contaminants were poorly correlated with other water parameters. Based on deviations from conservative mixing of fresh and salt water, three different patterns of possible sources of metals were identified in 1993. For dissolved chromium and lead, rivers and local runoff appeared to be important sources. For dissolved arsenic, cadmium, copper, and nickel year-round inputs from the South Bay appeared to be important sources. Dissolved mercury, selenium, and zinc were associated with local runoff in the South Bay during the wet period. Dissolved silver did not fit any of these patterns. Although most contaminant concentrations were below water quality objectives, several trace contaminants were above the objectives at some stations. Comparisons to water quality objectives are used as a guide for evaluation of contaminant concentrations, but there are some differences in the way the RMP data are measured and that prescribed for regulatory purposes (see text). Concentrations of 5 metals in water were above EPA or Regional Basin Plan water quality objectives at six stations (see Table 30). Most of these elevated levels occurred at the northern estuary stations. Total PCB concentrations were above EPA human health objectives at all RMP stations. The pesticides chlordane, dieldrin, and DDTs were above the EPA objectives at several RMP stations, particularly at the northern-most, and river confluence stations. Although some of the contaminant concentrations were above water quality objectives, water toxicity tests (96 hour algal growth and 48 hour bivalve larval development tests) did not indicate toxicity (sometimes inconclusive) associated with the water samples collected at any of the RMP stations in 1993. Exposure to Bay San Francisco Estuary Regional Monitoring Program Regional Monitoring Program 1993 Report ii water actually enhanced algal growth at most stations. In addition to the Estuary-wide sampling, the Sacramento and San Joaquin Rivers were sampled upstream from their confluence. Stations in each river were sampled six times over a 6 week period of high flows. In the Sacramento River, seven of the ten dissolved metals measured had concentrations lower than those measured at the river confluence stations. Some metals concentrations in the San Joaquin River were higher, and some were lower than concentrations from the river confluence station. Metals concentrations in the Sacramento River were poorly related to river flow because the station at Rio Vista is under considerable tidal influence. In the San Joaquin River, flows were inversely related to 7 of 10 total metals concentrations. Sediment Monitoring. Concentrations of silver, mercury, and lead in sediment were highest in the South Bay. However, concentrations of most trace metals in sediments were highest in the northern estuary at stations with the finest (silt, clay) sediments. The northern estuary stations with the coarsest (sand, shell) sediments generally had the lowest metals concentrations. There were differences in concentrations of cadmium, lead, and selenium in sediments between the sampling periods, but no consistent trend as to which sampling period had higher values. In September, PAHs and PCBs in sediments were highest in the Central Bay, but pesticides in sediments were highest in the northern estuary and Extreme South Bay. NOAA’s Median Effects Ranges (ERM) for sediments were used as a guide for evaluation of sediment contaminant concentrations. Nickel was the only trace contaminant in sediment above the ERM guidelines, and it was high at all RMP stations. These high levels are probably due to natural, geologic sources. Although sediment contaminant concentrations were below ERMs, sediment toxicity tests (10 day amphipod mortality, and 48 hour bivalve larval development in elutriates) indicated toxicity at all stations tested. Sediment factors that could have caused the toxicity were not investigated. Bivalve Bioaccumulation. Mussels, oysters, and freshwater clams were transplanted to the RMP stations to evaluate bioaccumulation of trace substances. Trace metals were bioaccumulated at nearly all RMP stations. However, arsenic, lead, and mercury did not appear to bioaccumulate. There was generally more bioaccumulation during the dry season than during the wet season. In September, PAHs, PCBs, and pesticides accumulated in all samples. Bioaccumulation of PAHs and pesticides was generally highest at the river confluence stations, and the Napa River. PCBs accumulated most at Redwood Creek. There were substantial differences in the degree of bioaccumulation among the species. Oysters appeared to accumulate higher concentrations of trace metals than the other species, especially copper, which may be a natural phenomenon. There are no established tissue contaminant standards for trace metal and organic contaminants. Therefore, comparisons to Median International Standards (MIS) for human consumption, or U.S. Food and Drug Administration (USFDA) action levels for trace organics are used to evaluate the bioaccumulation results. Concentrations of selenium were higher than MIS guidelines at all stations during the wet season. Other trace metal concentrations were higher than MIS guidelines at various stations during one or the other sampling period. However, none of the bivalves contained concentrations above the USFDA or National Academy of Sciences (NAS) guidelines for trace organic contaminants. The transplanted bivalves survived well at all stations except in the Napa River where less than 35% survived during both sampling seasons. Measures of bivalve condition (dry weight, shell volume) indicated that bivalves deployed in the Central Bay grew significantly, but those at most other stations actually lost weight. Whether these differences were due to natural causes such as salinity or food supply, or to contamination, was not determined. Pilot Studies. Two pilot monitoring studies were conducted in 1993. A pilot study of Estuary hydrography and phytoplankton was conducted by scientists from the U.S. Summary Geological Survey in Menlo Park and U.C. Davis. Water column profiles at up to 37 stations were monitored along a transect of the Estuary run monthly between the South Bay and the Delta. The primary objective of this study was to define physical (salinity, temperature, suspended particulate matter, and light penetration), chemical (dissolved oxygen) and biological (chlorophyll a) characteristics of Estuary water that may influence other chemical and biological reactions. A second objective was to investigate planktonic indicators of ecosystem structure and function. The data collected in 1993 showed the extent and duration of the spring phytoplankton bloom in the South Bay, other localized blooms in the northern estuary, the stratification and mixing associated with the entrapment zone in the northern estuary, and mixing in the Estuary resulting from the high rainfall in 1993. Knowledge of the duration and extent of these natural features of the Estuary provide context for interpretation of the RMP contaminant data collected only 3 times per year. Another pilot study of suspended sediment transport processes was conducted by the USGS in Sacramento. This study used continuous recording sensors at Point San Pablo and the Bay Bridge to measure the amount of suspended sediment in the water at mid-depth and near the bottom, as well as tide height. The objectives of this study were to estimate which factors determine suspended solids concentrations in the Central Bay and to collect time series of suspended solids that are appropriate for continuous monitoring of suspended solids and for calibration and validation of numerical models. The investigators determined that spring tides accounted for most of the variation in suspended solids concentrations at the stations monitored, not runoff from the Sacramento or San Joaquin Rivers, or semidiurnal and diurnal tides. Comparisons were also made between measurements made by the continuous recordings and the RMP samples collected during the regular monitoring cruises. The different ways of measuring TSS were generally comparable, however only 3 measurements per year as made by the RMP could not provide the information of TSS variation actually occurring in the Estuary. This information is important because as shown by the RMP data, total contaminant concentrations in Estuary water is largely dependent on the TSS in the water. This implies that the RMP measurements alone cannot determine accurately the range of contaminant concentrations without better characterizing the dynamics of TSS. The RMP Pilot Studies are important to the developing RMP because they will help put RMP measurements into the perspective of Estuary processes and mechanisms at other time scales. The studies can relate those processes to the RMP measurements and will facilitate revision of sampling design and interpretation. Summaries of other monitoring activities pertinent to regional monitoring are also included in the Report: a description of the Regional Board’s Bay Protection Studies, the Sacramento Coordinated Monitoring Program, and a wetlands monitoring plan are included.

California↗

USGS2019

Geochemical data for produced waters from conventional and unconventional oil and gas wells: Results from Colorado, USA

Geochemical data for more than 120,000 oil and natural gas wells from the major sedimentary basins in the USA are listed in the USGS National Produced Waters Geochemical Database [1]. In this summary, we report and discuss the geochemical data on produced waters obtained from published literature and the Colorado Oil and Gas Conservation Commission (COGCC) from close to 4,000 new oil and gas wells in Colorado. We emphasize geochemical data of produced waters from shale and tight reservoirs that have increased dramatically in Colorado since 2011, due to deep horizontal drilling, downhole telemetry and massive multi-stage hydraulic fracturing. These operations require large volumes of fresh water, but contamination of groundwater is the major environmental concern. Also, induced seismicity caused by water injection has been reported from several areas in Colorado, including Trinidad, Raton basin, and Greely, Denver basin. Produced water salinities in Colorado obtained from unconventional oil and gas wells are relatively low, generally less than 30,000 mg/L TDS. Produced water salinities from conventional oil and gas wells overlap those from unconventional wells, but many wells have higher salinities (up to 90,000 mg/L TDS) and different chemical compositions.

Colorado↗

USGS2015

Comparison of reintroduction and enhancement effects on metapopulation viability

Metapopulation viability depends upon a balance of extinction and colonization of local habitats by a species. Mechanisms that can affect this balance include physical characteristics related to natural processes (e.g. succession) as well as anthropogenic actions. Plant restorations can help to produce favorable metapopulation dynamics and consequently increase viability; however, to date no studies confirm this is true. Population viability analysis (PVA) allows for the use of empirical data to generate theoretical future projections in the form of median time to extinction and probability of extinction. In turn, PVAs can inform and aid the development of conservation, recovery, and management plans. Pitcher's thistle (Cirsium pitcheri) is a dune endemic that exhibited metapopulation dynamics. We projected viability of three natural and two restored populations with demographic data spanning 15–23 years to determine the degree the addition of reintroduced population affects metapopulation viability. The models were validated by comparing observed and projected abundances and adjusting parameters associated with demographic and environmental stochasticity to improve model performance. Our chosen model correctly predicted yearly population abundance for 60% of the population-years. Using that model, 50-year projections showed that the addition of reintroductions increases metapopulation viability. The reintroduction that simulated population performance in early-successional habitats had the maximum benefit. In situ enhancements of existing populations proved to be equally effective. This study shows that restorations can facilitate and improve metapopulation viability of species dependent on metapopulation dynamics for survival with long-term persistence of C. pitcheri in Indiana likely to depend on continued active management.

Indiana↗

USGS2021

Mixed evidence for biotic homogenization of southern Appalachian fish communities

Anthropogenic impacts on the landscape can drive biotic homogenization, whereby distinct biological communities become more similar to one another over time. Land-use change in the Southern Appalachian region is expected to result in homogenization of the highly diverse freshwater fish communities as in-stream habitat alterations favor widespread cosmopolitan species at the expense of more narrowly distributed highland endemic species. We compiled four datasets spanning 25 years to (1) evaluate the effects of environmental factors on relative abundance and richness of highland endemic vs. cosmopolitan species in this region and (2) test for taxonomic homogenization, measured as a change in beta diversity over time. We found that several environmental factors differentially affected highland endemic and cosmopolitan species, with the proportion of forested land cover in a watershed most strongly predicting higher relative abundance and richness of highland endemic species. Our analysis of beta diversity change, however, shows mixed evidence of taxonomic homogenization, depending on how common species are weighted. Shifts in community composition, with or without homogenization, may warrant attention in biodiversity conservation planning.

Georgia, North Carolina↗

USGS2001

Genetic variation in insecticide tolerance in a population of southern leopard frogs (Rana sphenocephala): Implications for amphibian conservation

Currently, conservation efforts are devoted to determining the extent and the causes of the decline of many amphibian species worldwide. Human impacts frequently degrade amphibian habitat and have been implicated in many declines. Because genetic variance is critical in determining the persistence of a species in a changing environment, we examined the amount of genetic variability present in a single population for tolerance to an environmental stressor. We examined the amount of genetic variability among full- and half-sib families in a single population of southern leopard frogs ( Rana sphenocephala ) with respect to their tolerance to lethal concentrations of the agricultural chemical, carbaryl. Analysis of time-to-death data indicated significant differences among full-sib families and suggests a large amount of variability present in the responses to this environmental stressor. Significant differences in responses among half-sib families indicated that there is additive genetic variance. These data suggest that this population may have the ability to adapt to environmental stressors. It is possible that declines of amphibian populations in the western United States may be attributed to low genetic variability resulting from limited migration among populations and small population sizes.

Missouri↗

USGS2019

Contemporary environmental assessment using a viability analysis in a large river system to inform restoration and adaptive management decisions

As large-scale restoration plans for degraded aquatic habitats evolve, it is essential that multiorganizational collaborations have a common vision to achieve consensus on restoration goals. Development of restoration targets and postrestoration monitoring strategies can be focused using a viability analysis framework that supports an adaptive management process. Viability analysis is a robust and accommodating framework, adaptable to any restoration monitoring program and, through the determination of common desired endpoints, can aid consensus building and collaboration across jurisdictional boundaries. In the St. Clair-Detroit River System, which is the Great Lakes connecting channel between southern Lake Huron and western Lake Erie, a viability analysis framework was used to evaluate environmental parameters associated with fisheries and aquatic restoration efforts and to gauge the overall health of the aquatic environment. Steps to derive the viability analysis were as follows: (1) establishing meaningful baseline metrics, (2) identifying information deficiencies, and (3) placing the context of current conditions into a usable format for managers and practitioners. Most geographic segments were designated in overall fair condition, and the conservation targets were designated in either good or fair condition, based on available assessed indicators. Many indicators were unable to be assessed or assigned condition status, which identified research and monitoring data gaps. Metrics associated with native migratory fishes, Lake St. Clair, and islands are generally in better condition than metrics associated with the coastal terrestrial systems, aerial migrants, and coastal wetlands. These results were not unexpected given the highly urbanized landscape of the St. Clair-Detroit River System. Resource managers in the corridor can use these results to identify knowledge gaps, research and restoration priorities, and to assess progress towards meeting restoration goals.

Michigan, Ontario↗

USGS2017

The Southern Appalachian Brook Trout management conundrum: What should restoration look like in the 21st Century?

Brook Trout Salvelinus fontinalis in the southern Appalachian portion of their range have been isolated in remote headwater systems for millennia. Recent genetic investigations indicate extremely low allelic diversity, heterozygosity and effective population sizes in many streams. In populations restored using multiple source stocks, limited introgression has been observed despite source stocks being collected from streams within the same subwatershed. It remains unclear if pre- and/or post-reproductive isolating mechanisms are restricting effective gene flow among source stocks in restored streams. Objectives of this study were to: 1) identify environmental variables contributing to assortative mating, and 2) use common garden crossings to determine if wild type brood stock crossings resulted in physiologically viable offspring. We observed markedly different fertilization success rates within-population (66.7%) and betweenpopulation (91.7%) from the 42 crosses (N=18 control, N=24 treatment). Moreover, we observed significant (P < 0.05) differences between within-population and between-population groups in each of our linear mixed effects global models for each trial stage of development (i.e., fertilization rate, eyed egg rate, and hatch rates). Tukey’s HSD comparisons revealed only one significantly (P < 0.003) different fertilization rate among the forty five pairwise comparisons in each of our three stages of trails. In addition, we observed differential peaks of gamete production within and among source stream brood stock, despite common garden conditions, that appeared to have limited fertilization success rates between interstream and control groups. Despite differential peak gamete timing, intrastream crosses performed equally, and, in some instances, better than those between control groups. Our results suggest differential responses to shared environmental conditions (i.e., temperature and/or photoperiod) may contribute to mismatched spawning phenology (i.e., gamete production timing) among restoration founder stocks leading to introgression (i.e., genetic admixture). The application of contemporary genetic techniques could help determine if these possible local adaptations are genetically fixed or may break down over time in restored populations with mixed source stocks. These findings demonstrate the need to apply contemporary conservation genetics tools to future wild trout restoration projects using translocated source stock towards the goal of “genetically-robust”, naturally reproducing populations with the ability to cope with current and future perturbations.

North Carolina, Tennessee↗

USGS2023

Appendix A: Modeling appendix for the Northwestern and Southwestern pond turtle (Actinemys marmorata , Actinemys pallida )

To predict future status of the northwestern pond turtle ( Actinemys marmorata ) and southwestern pond turtle ( Actinemys pallida ) species, we developed a stochastic stage-based matrix population model to simulate future population conditions. We constructed a demographic population viability analysis for each species based on a post-breeding, single sex, stage-based life history diagram elicited from taxa experts and derived from relevant literature. Demographic parameters were based on estimates from published literature and data provided to the U.S. Fish and Wildlife Service (USFWS). Using the most recent observations of turtles, available habitat, local abundances, and current threat conditions, we calculated spatially explicit initial abundances to initialize our stochastic projection. In order to incorporate multiple types of uncertainty (ecological, parametric, temporal), we built three embedded simulation loops within the simulation model. Representing ecological uncertainty, species status was projected into the future using multiple plausible future scenarios based on two representative concentration pathways (RCP 4.5, 8.5) and two shared socioeconomic pathways (SSP 2, 5) to reflect plausible alternative future trajectories of relevant environmental conditions. Parametric uncertainty was included for survival estimates of all life stages due the inconsistency of estimates across the species’ range. Temporal variability or environmental stochasticity was included in the form of randomized variation from the mean demographic parameter values in each year of the approximately 80-year simulation. The model output included probability of extinction and estimated abundance through 2100 for each unique Analysis Unit (AU) and for the full geographic range of the species except populations in the state of Washington. The AUs in Washington are conservation dependent and sustained by a head-starting and reintroduction program. Thus, the population dynamics do not match our model for the rest of the range and therefore the Washington AUs were included in this projection modeling effort. There is already pre-existing, detailed PVA for these specific populations (Pramuk et al. 2012, p.41-60), and the Status assessment report can use those results for inference about future status. We discuss the results of Pramuk et al. (2012, p.41-61) alongside our own. Probability of extinction was overall higher for the southwestern pond turtle as compared to the northwestern species and population growth rates were strongly negative for both species (approximately -3% annually for all AUs for all scenarios). This appendix is organized into three primary sections: 1) a description of the life history, the core population dynamics model, and demographic parameters, 2) a description of methods for establishing initial abundances of the populations for the future viability modeling, and 3) a description of the methods for modeling effects of various threats on future demographic rates and the results of future conditions scenarios.

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