SEARCH · Search USGS

Results for “Crop Protection”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources

USGS2015

Chemical mixtures and environmental effects: a pilot study to assess ecological exposure and effects in streams

Assessment and management of the risks of exposure to complex chemical mixtures in streams are priorities for human and environmental health organizations around the world. The current lack of information on the composition and variability of environmental mixtures and a limited understanding of their combined effects are fundamental obstacles to timely identification and prevention of adverse human and ecological effects of exposure. This report describes the design of a field-based study of the composition and biological activity of chemical mixtures in U.S. stream waters affected by a wide range of human activities and contaminant sources. The study is a collaborative effort by the U.S. Geological Survey and the U.S. Environmental Protection Agency. Scientists sampled 38 streams spanning 24 States and Puerto Rico. Thirty-four of the sites were located in watersheds impacted by multiple contaminant sources, including industrial and municipal wastewater discharges, crop and animal agricultural runoff, urban runoff, and other point and nonpoint contaminant sources. The remaining four sites were minimally development reference watersheds. All samples underwent comprehensive chemical and biological characterization, including sensitive and specific direct analysis for over 700 dissolved organic and inorganic chemicals and field parameters, identification of unknown contaminants (environmental diagnostics), and a variety of bioassays to evaluate biological activity and toxicity.

Open-File Report↗

USGS2021

Land use change and climate-smart agriculture in the Sahel

In the 1970s and 1980s, the Sahel experienced recurrent drought and famine. Farmers and their development partners reacted to this crisis by developing climate-smart agricultural practices and changes in land use, including water-harvesting techniques to restore degraded land to productivity. In several densely populated parts of the Sahel, farmers began to protect and manage woody species that regenerated naturally on their farmland. Farmer-managed natural regeneration (FMNR) is a foundational practice that produces multiple benefits, such as maintaining or improving soil fertility, which raises crop yields, and increasing the production of tree-based fodder, fruit, and firewood. In Niger’s Maradi and Zinder Regions alone, farmers have applied FMNR practices on 4.2 million hectares. The findings presented in this chapter suggest that the future of agriculture in the Sahel will be largely determined by whether low-income smallholder farmers will manage to improve soil fertility, which will depend on maintaining substantial densities of on-farm trees thus increasing tree cover.

Sahel Region↗

USGS2026

When best intentions are not enough - A collaboration between scientists, policymakers, and an agricultural community

Rocky Mountain National Park is a Congressionally mandated Clean Air Act Class I Area, but years of research have documented evidence of biogeochemical and ecological change caused by atmospheric deposition of nitrogen. A coalition of government agencies—National Park Service, the Environmental Protection Agency Region 8, and the State of Colorado—developed the 2007 Nitrogen Deposition Reduction Plan to reduce wet nitrogen deposition to the park from the baseline in 2006 by 50% by 2032. Fifty-four percent of wet nitrogen deposition is ammonium, primarily sourced from industrial cattle and dairy operations east of the park. An Agriculture Subcommittee, meeting with regulatory and management agencies and scientists since 2006, has explored voluntary options to reduce ammonia emissions. Ammonia emissions are unregulated in the U.S. Despite sustained efforts, neither ammonium deposition nor total inorganic nitrogen deposition have declined at the rate determined to reach the targeted value by 2032. In fact, ammonia is increasing over the Front Range agricultural area. Wet nitrogen deposition in 2024 was 2.81 kg N ha −1 yr −1 , 0.61 kg N ha −1 yr −1 higher than targeted in the Nitrogen Deposition Reduction Plan. The collaborative approach between agricultural producers, regulatory entities, and resource managers is not working, but not for lack of effort by all parties. Cattle process nitrogen inefficiently, and while management practices can somewhat reduce the proportion of ammonia emitted from feedlots, with more than one million head of cattle east of Rocky Mountain National Park, large-scale reductions are unlikely. New programs to reduce emissions of nitrogen oxides (46% of wet nitrogen deposition) may reduce nitrogen deposition that is changing park ecosystems. Improved integration of crop and livestock agriculture and valuation of the ecosystem services and economy of Rocky Mountain National Park alongside agricultural value are topics for further discussion. Implications : Nitrogen deposition in precipitation to Rocky Mountain National Park has changed natural ecosystems. To protect its Clean Air Act Class I status a 2007 Nitrogen Deposition Reduction Plan agreed upon by state and federal agencies set a goal to reduce wet nitrogen deposition to the Park by half by 2032. Industrial livestock operations are a large source of nitrogen; an Agriculture Subcommittee explored voluntary options to reduce emissions from cattle. Despite sustained efforts nitrogen deposition has not declined. Further reductions in industry and transportation emissions will be needed reduce nitrogen deposition to Rocky Mountain National Park.

Colorado↗

USGS2012

Exploring relationships among land ownership, agricultural land use, and native fish species richness in the Upper Mississippi River Basin

The general effects of agriculture on in-stream fish communities in the Upper Midwestern United States have been well studied for nearly three decades (Karr et al. 1985; Nerbonne and Vondracek 1991; Zimmerman et al. 2001; Goldstein and Meador 2005). Specific impacts include: lowered water levels, sediment loading and nutrient enrichment, loss of riparian habitat, changes to channel morphometry and physical habitat, and changes to the forage base. As part of the National Fish Habitat Action Plan (NFHAP), an initiative to protect, restore, and enhance the nation's fish and aquatic communities, the Fishers and Farmers Partnership specifically focuses on working with agricultural producers to help protect and restore aquatic resources in the Upper Mississippi River Basin (UMRB) (Fig. 1). Successful protection and/or restoration will require the partnership and local conservation agencies to effectively communicate and work with local landowners. However, roughly 43% of the agricultural lands in the UMRB are not operated by those who own the land (National Agricultural Statistics Service 2009) and this is expected to increase as heirs of farm estates now reside greater distances from their home farms than ever before (Arbuckle 2010). It has long been presumed that changes in land ownership trends, toward more absentee landowners, would have important consequences for soil erosion and other conservation practices, as larger, more corporate agriculture, is thought to maximize farm income at the expense of environmental quality (Lee 1980). Absentee landowners may be less likely to take advantage of conservation programs. For example, land operated by renters lags enrollment in the Conservation Reserve (CRP) and Wetland Reserve (WRP) programs by 64% nation-wide (Petrzelka et al. 2009). Also, it has been found that the more detached an absentee landowner becomes from their land, both geographically and culturally, their commitment to land stewardship decreases (Arbuckle 2010). The Fishers and Farmers Partnership recognizes the challenge agricultural producers face in maintaining food and fiber production for a growing world population while also trying to improve environmental quality and fish habitat. This challenge is likely exacerbated when the landowners are absentee. Thus, reaching non-owner-operated farmers and convincing them to help protect and/or restore aquatic resources may be critical to the success of the Fishers and Farmers Partnership. In this study, we explored relationships among agricultural land use, land ownership, and native fish biodiversity in the UMRB as a first step toward helping the Fishers and Farmers Partnership identify specific locations in the UMRB that may pose conservation challenges. For example, places that have experienced a loss of native fish species richness relative to historical conditions and also have high proportions of absentee landowners may provide restoration challenges. We were also interested in identifying areas that have retained high levels of species richness and are owner-operated. These areas present good opportunities to work with local landowners to protect aquatic resources. To identify such areas, we addressed two primary questions: 1) Is there a relationship between the type of agricultural land use (i.e. cropland vs pastureland) and the % of land rented or leased within the UMRB? and 2) How does the type of agricultural production and whether land is rented or leased relate to the maintenance of historical levels of native fish species richness? We predicted that areas with large amounts of land devoted to crop production will have experienced the greatest losses of native fish species richness. However, our hypothesis is that watersheds with large amounts of land rented or leased will have experienced even greater declines in native fish species richness than would be predicted from the amount of cultivated cropland alone. By testing these hypotheses, we intended to identify watersheds that would be strong candidates for protection, restoration, and enhancement of fish species richness by accounting for land use and ownership characteristics.

Illinois, Indiana, Iowa, Michigan, Minnesota, Miss↗

USGS2025

Pathways for potential exposure to onshore oil and gas wastewater: What we need to know to protect human health

Produced water is a chemically complex waste stream generated during oil and gas development. Roughly four trillion liters were generated onshore in the United States in 2021 (ALL Consulting, 2022, https://www.gwpc.org/wp-content/uploads/2021/09/2021_Produced_Water_Volumes.pdf ). Efforts are underway to expand historic uses of produced water to offset freshwater needs in water-stressed regions, avoid induced seismic activity associated with its disposal, and extract commodities. Understanding the potential exposures from current and proposed produced water uses and management practices can help to inform health-protective practices. This review summarizes what is known about potential human exposure to produced water from onshore oil and gas development in the United States. We synthesize 236 publications to create a conceptual model of potential human exposure that illustrates the current state of scientific inquiry and knowledge. Exposure to produced water can occur following its release to the environment through spills or leaks during its handling and management. Exposure can also arise from authorized releases, including permitted discharges to surface water, crop irrigation, and road treatment. Knowledge gaps include understanding the variable composition and toxicity of produced water released to the environment, the performance of treatment methods, migration pathways through the environment that can result in human exposure, and the significance of the exposures for human and ecosystem health. Reducing these uncertainties may help in realizing the benefits of produced water use while simultaneously protecting human health.

Environmental Health Perspectives↗

USGS1997

Evaluation of agricultural best-management practices in the Conestoga River headwaters, Pennsylvania: Effects of nutrient management on quality of surface runoff and ground water at a small carbonate-rock site near Ephrata, Pennsylvania, 1984-90

The U.S. Geological Survey and the Pennsylvania Department of Environmental Protection conducted a study from 1984 to 1990 to determine theeffects of the implementation and practice of nutrient management [an agricultural best-management practice (BMP)] on the quality of surface runoff and ground water at a 55-acre crop and livestock farm in carbonate terrain nearEphrata, Pa. Implementation of nutrient management at Field-Site 2 resulted in application decreases of 33 percent for nitrogen and 29 percent for phosphorus. There wereno significant changes in nitrogen or phosphorusloads for a given amount of runoff from the pre-BMP to the post-BMP periods. However, less than 2 percent of the applied nutrients weredischarged with runoff throughout the study period.After the implementation of nutrient management, statistically significant decreases in concentrations of nitrate in ground-water samples occurred at threeof the four wells monitored throughout the pre- and post-BMP periods. The largest decreases in nitrate concentrations occurred at wells where samples hadthe largest nitrate concentrations prior to nutrient management. Changes in nitrogen applications to the contributing areas of five wells were correlated with nitrate concentrations of the well water. The correlations between the timing and amount of applied nitrogen and changes in ground-water quality met the four conditions that are characteristic of a cause-effect relation: an association, consistency, responsiveness, and a mechanism. Changes in ground-water nitrate concentrations lagged behind changes in loading of nitrogen fertilizers (primarily manure) by approximately 4 to 19 months.

Pennsylvania↗

USGS2012

Corpus Christi, Nueces, and Aransas Bays: Chapter C in Emergent wetlands status and trends in the northern Gulf of Mexico: 1950-2010

Corpus Christi Bay and Nueces Bay comprise the middle estuarine portion of Texas’ Coastal Bend region (Figure 1; Burgan and Engle, 2006). Aransas Bay is part of the upper estuarine portion of the region. These bays make up part of the Coastal Bend Bays and Estuaries Program, one of the many estuarine areas in the U.S. Environmental Protection Agency’s National Estuary Program (Holt, 1998). The Coastal Bend region is sub-humid and sub-tropical. Summers are long, hot, and humid, and winters are short and mild. The landscape around the estuaries is dominated by row crops, pastures, and brushy rangeland (Handley and others, 2007). The Nueces River, along with other smaller rivers and creeks, provides freshwater inflow - along with essential nutrients and sediment - into Nueces Bay, which feeds into Corpus Christi Bay (Holt, 1998). Freshwater inflow into the Aransas Bay comes from Mission River, Aransas River, and Copano Creek. The region is relatively dry otherwise and prone to droughts. Corpus Christi receives an average of 76.2 cm (30 in) of rain annually; evaporation usually exceeds 177.8 cm (70 in) (Holt, 1998; Handley and others, 2007). The San Antonio-Nueces Coastal Basin drains into Aransas Bay. The Nueces River basin covers 43,253 km 2 (16,700 miles 2 ), from northwest of San Antonio, flowing southeast to where it drains into Nueces and Corpus Christi Bays (Holt, 1998). The Nueces-Rio Grande basin covers approximately 18,648 km 2 (7,200 miles 2 ) and flows partially into Corpus Christi Bay (as well as the upper Laguna Madre). The inflow from Nueces River has declined by approximately 20 percent over the past several decades, partly due to construction of lakes and reservoirs, particularly Lake Corpus Christi and Choke Canyon reservoir. The Corpus Christi Estuary receives approximately 35 percent of the total freshwater inflow of 1,480,178,205 cubic meters (m 3 ) (1.2 million acre-feet) in the region; the Aransas Estuary receives about 53 percent. Tidal range is only 0.46 m (1.5 ft) on the Gulf shoreline and 0.15 m (0.5 ft) in Nueces Bay. Strong winds are the primary force behind water circulation in the Coastal Bend estuaries.

Texas↗

USGS1996

Geohydrologic units and water-level conditions in the Terrace alluvial aquifer and Paluxy Aquifer, May 1993 and February 1994, near Air Force Plant 4, Fort Worth area, Texas

The terrace alluvial aquifer underlying Air Force Plant 4 and the adjacent Naval Air Station (formerly Carswell Air Force Base) in the Fort Worth area, Texas, is contaminated locally with organic and metal compounds. Residents south and west of Air Force Plant 4 and the Naval Air Station are concerned that contaminants might enter the underlying Paluxy aquifer, which provides water to the city of White Settlement, south of Air Force Plant 4, and to residents west of Air Force Plant 4. The U.S. Environmental Protection Agency has qualified Air Force Plant 4 for Superfund cleanup. The pertinent geologic units include -A~rom oldest to youngest the Glen Rose, Paluxy, and Walnut Formations, Goodland Limestone, and terrace alluvial deposits. Except for the Glen Rose Formation, all units crop out at or near Air Force Plant 4 and the Naval Air Station. The terrace alluvial deposits, which nearly everywhere form the land surface, range from 0 to about 60 feet thick. These deposits comprise a mostly unconsolidated mixture of gravel, sand, silt, and clay. Mudstone and sandstone of the Paluxy Formation crop out north, west, and southwest of Lake Worth and total between about 130 and about 175 feet thick. The terrace alluvial deposits and the Paluxy Formation comprise the terrace alluvial aquifer and the Paluxy aquifer, respectively. These aquifers are separated by the Goodland-Walnut confining unit, composed of the Goodland Limestone and (or) Walnut Formation. Below the Paluxy aquifer, the Glen Rose Formation forms the Glen Rose confining unit. Water-level measurements during May 1993 and February 1994 from wells in the terrace alluvial aquifer indicate that, regionally, ground water flows toward the east-southeast beneath Air Force Plant 4 and the Naval Air Station. Locally, water appears to flow outward from ground-water mounds maintained by the localized infiltration of precipitation and reportedly by leaking water pipes and sanitary and (or) storm sewer lines beneath the assembly building at Air Force Plant 4. North of Farmers Branch, the terrace alluvial aquifer discharges into Lake Worth, Meandering Road Creek, Farmers Branch, and the West Fork Trinity River. South of Farmers Branch, ground water appears to flow mostly north-northeastward. Greater precipitation prior to the May 1993 measurements caused water levels to average approximately 5 ft higher in May 1993 than in February 1994. Regional ground-water gradients indicate west to east-southeastward flow in the Paluxy aquifer, with a dominant southeastward component beneath Air Force Plant 4. Water-level maps for the Paluxy "upper sand" reveal an elongated groundwater mound beneath southeastern parts of Air Force Plant 4, which indicates a localized, vertical conduit through which contaminated water from the terrace alluvial aquifer might enter upper parts of the Paluxy aquifer. The Paluxy "upper sand" apparently is mostly unsaturated and hydraulically separated from the deeper, regionally extensive parts of the Paluxy aquifer, most of which are fully saturated. While water levels in the "upper sand" were as much as 10 ft higher in May 1993 than in February 1994, water levels in most deeper parts of the Paluxy aquifer were slightly higher in February 1994 than they were in May 1993.

Texas↗

USGS2022

Pesticide exposure of wild bees and honey bees foraging from field border flowers in intensively managed agriculture areas

Bees are critical for food crop pollination, yet their populations are declining as agricultural practices intensify. Pollinator-attractive field border plantings (e.g. hedgerows and forb strips) can increase bee diversity and abundance in agricultural areas, however recent studies suggest these plants may contain pesticides. Pesticide exposure for wild bees in agricultural areas remains largely unknown, however this information is needed to inform agricultural practices and pesticide regulations meant to protect bees. It is important to determine whether border plantings that attract and support pollinators by providing floral resources may also deliver pesticides to them. In this study, we collected various samples for pesticide residue analysis including: multiple species of wild bees, honey bees, flowers from four types of bee-attractive field border plants, and soil. Silicone bands were also utilized as passive aerial samplers of pesticide residues. The five pesticides detected most frequently across all samples were the insecticide bifenthrin, the herbicides thiobencarb, metolaclor, and propanil, and the fungicide fluopyram. We detected the greatest number of parent pesticides in passive aerial samplers (24), followed by soil (21). Pesticides were also detected in field border plant flowers (16), which do not receive direct pesticides applications and many of which were not applied to adjacent field crops. Pesticide concentrations were lower in bees than in flowers but higher in bees than in soils. Pesticide residue per bee (ng/bee) increased with increasing wild bee size, though pesticide concentration (ng/g) did not increase. While honey bees and wild bees contained a similar number and concentration of pesticides overall, pesticide mixtures varied by bee type, and included some mixtures known to cause sublethal effects. The results from this study highlight the benefits of measuring more sample types to capture the total exposome of bees, including a greater range of bee species, as well as the need to consider exposure to pesticides at the landscape level.

California↗

USGS2011

Setting limits: Using air pollution thresholds to protect and restore U.S. ecosystems

More than four decades of research provide unequivocal evidence that sulfur, nitrogen, and mercury pollution have altered, and will continue to alter, our nation's lands and waters. The emission and deposition of air pollutants harm native plants and animals, degrade water quality, affect forest productivity, and are damaging to human health. Many air quality policies limit emissions at the source but these control measures do not always consider ecosystem impacts. Air pollution thresholds at which ecological effects are observed, such as critical loads, are effective tools for assessing the impacts of air pollution on essential ecosystem services and for informing public policy. U.S. ecosystems can be more effectively protected and restored by using a combination of emissions-based approaches and science-based thresholds of ecosystem damage. Based on the results of a comprehensive review of air pollution thresholds, we conclude: ??? Ecosystem services such as air and water purification, decomposition and detoxification of waste materials, climate regulation, regeneration of soil fertility, production and biodiversity maintenance, as well as crop, timber and fish supplies are impacted by deposition of nitrogen, sulfur, mercury and other pollutants. The consequences of these changes may be difficult or impossible to reverse as impacts cascade throughout affected ecosystems. ??? The effects of too much nitrogen are common across the U.S. and include altered plant and lichen communities, enhanced growth of invasive species, eutrophication and acidification of lands and waters, and habitat deterioration for native species, including endangered species. ??? Lake, stream and soil acidification is widespread across the eastern United States. Up to 65% of lakes within sensitive areas receive acid deposition that exceeds critical loads. ??? Mercury contamination adversely affects fish in many inland and coastal waters. Fish consumption advisories for mercury exist in all 50 states and on many tribal lands. High concentrations of mercury in wildlife are also widespread and have multiple adverse effects. ??? Air quality programs, such as those stemming from the 1990 Clean Air Act Amendments, have helped decrease air pollution even as population and energy demand have increased. Yet, they do not adequately protect ecosystems from long-term damage. Moreover they do not address ammonia emissions. ??? A stronger ecosystem basis for air pollutant policies could be established through adoption of science-based thresholds. Existing monitoring programs track vital information needed to measure the response to policies, and could be expanded to include appropriate chemical and biological indicators for terrestrial and aquatic ecosystems and establishment of a national ecosystem monitoring network for mercury. The development and use of air pollution thresholds for ecosystem protection and management is increasing in the United States, yet threshold approaches remain underutilized. Ecological thresholds for air pollution, such as critical loads for nitrogen and sulfur deposition, are not currently included in the formal regulatory process for emissions controls in the United States, although they are now considered in local management decisions by the National Park Service and U.S. Forest Service. Ecological thresholds offer a scientifically sound approach to protecting and restoring U.S. ecosystems and an important tool for natural resource management and policy. ?? The Ecological Society of America.

Issues in Ecology↗

USGS2005

Grass buffers for playas in agricultural landscapes: A literature synthesis

We summarize current knowledge about grass buffers for protecting small, isolated wetlands in agricultural contexts, including information relevant to protecting playas from runoff containing sediments, nutrients, pesticides, and other contaminants, and information on how buffers may affect densities and productivity of grassland birds. Land-uses surrounding the approximately 60,000 playas within the Playa Lakes Region (PLR), including intensive agriculture, feedlots, and oil extraction, can contribute to severe degradation of playas. Farming and grazing can lead to significant sedimentation in nearby playas, eliminating their ability to hold water, support the region’s biodiversity, or adequately recharge aquifers. Contaminants further degrade habitats and threaten the water quality of underlying aquifers, including the Ogallala Aquifer. Grass buffers hold promise as a management tool to reduce the amount of sediments and contaminants from agricultural runoff that enters playas. Effective buffer width is determined by acceptable sediment-reduction levels, potential water flow and velocity, landscape and soil variables, buffer species, and vegetation structure. Various models have been developed to predict buffer effectiveness; however, most of these models, including those provided by the Natural Resource Conservation Service (NRCS), remain unvalidated. The majority of buffer-effectiveness literature is based on simulated conditions in experimental trays or plots; no published studies of buffer design or effectiveness specifically address playas. Nonetheless, some general patterns have emerged regarding buffer design/effectiveness. Buffers 10–60 m wide are generally considered adequate for trapping most sediments, although in some cases buffers need to be >200 m. The U.S. Fish and Wildlife Service Partners for Wildlife Program in the Southern High Plains recommend a buffer width of ~33 m planted with a diverse mix of native shortgrasses and mixed grasses as a starting point. Most dissolved contaminants, however, are removed from runoff only when they infiltrate the soil, where microbes or other processes can break down or sequester contaminants. Promoting runoff infiltration requires wider buffers with denser stem densities than those required for filtering sediments, which may result in hydrological changes in playas. Ultimately, the balance between runoff and infiltration determines whether or not water eventually reaches a given basin. Long-term buffer effectiveness requires regular maintenance, including excavation to remove overburdens of sediments, repairing vegetation damage, and removing over-mature vegetation or invasions of noxious weeds. Buffers may not be enough to protect playas; best management practices (BMPs; e.g., conservation tillage, contour tilling, and mulching herbicides into soil after application) that diminish soil erosion and contaminant runoff also may be necessary. Nutrient loads in runoff can be minimized by balancing nutrient input with nutrient requirements for livestock and crops. Pesticide application practices also require careful evaluation. Mowing or grazing rather than use of herbicides offer alternatives for suppressing invasive or undesirable plant species in buffers. Future research should entail multiple-scale approaches at regional, wetland-complex, and individual watershed scales. Information needs include direct measures of buffer effectiveness in ‘real-world’ systems, refinement and field tests of buffer-effectiveness models, how buffers may affect floral and faunal communities of playas, and basic ecological information on playa function and playa wildlife ecology. Understanding how wildlife communities respond to patch size and habitat fragmentation is crucial for addressing questions regarding habitat quality of grass buffers in playa systems.

Open-File Report↗

USGS2017

Anticoagulant rodenticides and wildlife: Concluding remarks

Rodents are known to affect human society globally in various adverse ways, resulting in a widespread demand for their continuous control. Anticoagulant rodenticides (ARs) have been, and currently remain, the cornerstone of rodent control throughout the world. Although alternative control methods exist, they are generally less effective. ARs work by affecting vitamin K metabolism, thereby preventing the activation of blood clotting factors and eventual coagulopathy. Since ARs are non-selective, their undoubted benefits for rodent control have to be balanced against the environmental risks that these compounds pose. Although they have been used for decades, pharmacokinetic and toxicokinetic data are mainly available for laboratory mammals and have concentrated on acute effects. Limited information is available on chronic exposure scenarios and for wildlife species. Important gaps exist in our understanding of the large inter- and intra-species differences in sensitivity to ARs, especially for non-target species, and in our knowledge about the occurrence and importance of sub-lethal effects in wildlife. It is clear that mere presence of AR residues in the body tissues may not indicate the occurrence of effects, although unequivocal assessment of effects under field conditions is difficult. Ante-mortem symptoms, like lethargy, subdued behaviour and unresponsiveness are generally not very specific as is true for more generic post-mortem observations (e.g. pallor of the mucous membranes or occurrence of haemorrhages). It is only by combining ante or post-mortem data with information on exposure that effects in the field may be confirmed. We do know however that a wide variety of non-target species are directly exposed to ARs. Secondary exposure in predators is also widespread although there is limited information on whether this exposure causes actual effects. Exposure is driven by ecological factors and is context specific with respect to spatial habitat configuration and bait placement. Another key factor that affects the interaction between ARs and wildlife is the development of resistance in target species. The development of resistance has resulted in higher use of SGARs, thereby increasing the potential of non-target and secondary exposure. AR use has increasingly become more strictly regulated, increasing the need for alternatives. Alternatives are available, including non-anticoagulant rodenticides, but these may also pose significant risk to environmental organisms, humans and pets. There are also various mitigation measures that can be implemented when using ARs, including bait protection, pulsed baiting at the onset of infestation, restricting use by non-professionals, and avoiding use in areas of high non-target density. Reduction in secondary exposure may result from e.g. non-chemical control, habitat management, and, in agricultural habitats, the use of lure crops and supplemental feeding. Such Integrated Pest Management (IPM) may not only reduce non-target exposure but also benefit resistance management. Barriers to adopt IPM approaches however, include the perception that they do not work or too slowly and are more laborious, expensive and time consuming. It is therefore important that the expectations of stakeholders are considered and managed. Nevertheless, further development of alternatives and IPM measures is essential, so the key research priority related to rodent control may ultimately be to address the lack of scientific assessment of the effectiveness of both specific AR mitigation measures and of IPM approaches to rodent control.

Book chapter↗

USGS2002

The impact of buffer strips and stream-side grazing on small mammals in southwestern Wisconsin

The practice of continuously grazing cattle along streams has caused extensive degradation of riparian habitats. Buffer strips and managed intensive rotational grazing (MIRG) have been proposed to protect and restore stream ecosystems in Wisconsin. However, the ecological implications of a switch from traditional livestock management to MIRG or buffer strip establishment have not been investigated. Differences in small mammal communities associated with riparian areas on continuously grazed and MIRG pastures, as well as vegetative buffer strips adjacent to row crops, were investigated in southwestern Wisconsin during May-September 1997 and 1998. More species (mean of 6-7) were found on the buffer sites than on the pasture sites (mean of 2-5). Total small mammal abundance on buffer sites was greater than on the pastures as well: there were 3-5 times as many animals on the buffer sites compared to the pasture sites, depending on year. There were no differences in species richness or total abundance between MIRG and continuously grazed pastures in either year. Total small mammal abundance was greater near the stream than away from the stream, regardless of farm management practice but there were no differences in species richness. Buffer strips appear to support a particularly rich and abundant small mammal community. Although results did not detect a difference in small mammal use between pasture types, farm-wide implications of a conversion from continuous to MIRG styles of grazing may benefit small mammals indirectly by causing an increase in the prevalence of pasture in the agricultural landscape.

Agriculture, Ecosystems and Environment↗

USGS2025

Population estimates and land cover use of wintering Mountain Plovers in Texas

Conservation of migratory birds throughout the full annual cycle requires a comprehensive understanding of abundance and distribution in interconnected breeding, migration, and wintering habitats. The Mountain Plover ( Anarhynchus montanus ) is a rare endemic breeder of the Rocky Mountain and Great Plains regions that migrates to wintering grounds in the southwestern USA and northern Mexico. Information regarding its wintering abundance and distribution, particularly in Texas, is limited. This study provides the first population estimate for Mountain Plovers wintering in Texas and examines factors influencing their land cover use. Through distance sampling surveys in six ecoregions of Texas, we estimated an annual wintering population of 3096 (95% CI 1464–6547) Mountain Plovers during 2019–2020, with the greatest abundances in the Southern Texas Plains and Western Gulf Coastal Plain ecoregions. The highest plover densities were in the Southern Texas Plains and Central Great Plains ecoregions. Most plovers were found in cultivated crops, particularly tilled fields and sod farms, and plovers preferentially selected crop fields without residual vegetation or stubble. Grass/hay fields were used less, perhaps because of tall vegetation. Our findings highlight the significance of Texas as a wintering area for Mountain Plovers and emphasize the importance of specific cropland habitats for this species. These results provide crucial insights for conservation and management efforts aimed at protecting Mountain Plovers throughout their annual cycle.

Texas↗

USGS2025

Fine-scale farming features drive resource selection of a small carnivore of conservation concern

Anthropogenic factors are accelerating species extinction, with small mammalian carnivores among the most affected. These species play vital ecological roles, yet their conservation needs are often overlooked. Our study focused on the plains spotted skunk ( Spilogale interrupta (Rafinesque, 1820)), a small carnivore that has experienced population declines. We hypothesized that their resource selection was influenced by factors expected to influence prey availability, protection from predators, and human activity. We tracked 14 plains spotted skunks in east-central South Dakota, USA, over 2 years during spring and summer. Using mixed-effects logistic regression, we identified seasonal habitat associations. In spring, plains spotted skunks selected areas near farming structures and human development, avoiding high wetland density and crop cover. In summer, they continued to select areas near farming structures and low human development, but also high wetland density and pasture, while avoiding hay bales and crop cover. Our first analysis of the species’ resource use in the Great Plains indicates that plains spotted skunks select habitats with permanent small-scale agricultural features and varying levels of human development across seasons. Our findings suggest that species’ persistence in the region may depend on conservation strategies that account for seasonal planning, habitat heterogeneity, and key agricultural structures.

Canadian Journal of Zoology↗

USGS2005

Determining forage availability and use patterns for bison in the Hayden Valley of Yellowstone National Park

In our original Proposal, we identified 4 objectives: 1. Delineate seasonal forage use patterns by bison in the Hayden Valley; 2. Determine long and short term effects of ungulate foraging on vegetation in the Hayden Valley; 3. Determine efficacy of vegetation monitoring approaches; 4. Estimate annual production and standing crop available during non-growing seasons for herbaceous and shrub layers in major habitat types in the Hayden Valley. Our efforts to describe forage use by bison focused on assessing finer scale habitat use is a core summer range for bison in YNP. We also collected information on bison food habits and forage quality to begin to explain the “whys” of bison distribution. Short-term impacts of bison forage utilization were addressed by comparing standing biomass in plots protected from grazing with plots exposed to grazing. Historical data were not available to directly address long-term effects of ungulate foraging in the Hayden Valley, but we were able to indirectly assess some aspects of this question by determining the frequency of repeat grazing over a 3-year period and the rate at which trees along the margins of the Hayden Valley were being killed by bison rubbing The third objective, determining the relative efficacy of different vegetation monitoring approaches, was accomplished by comparing estimates of standing biomass and biomas: utilization obtained via conventional exclosure techniques with estimates based on remote sensing techniques (ground-based and satellite-borne multi-spectral radiometry|[MSR]). We addressed efficacy in terms of precision and accuracy of estimates, reliability, and logistical costs at different coverage scales. The fourth objective, estimation of forage available for ungulates in the Hayden Valley, was achieved using conventional exclosure methodology and remote sensing. We were able to estimate herbaceous biomass production during 3 different years. Exclosures allowed us to estimated changes instanding crop of herbaceous vegetation at the plant community (conventional cover types, moisture plant growth form groups, and communities defined by dominant graminoids) and catena (a repeating sequence of communities tied to landscape physiognomy) scales. We developed empirical approaches that allowed us to estimate standing biomass of herbaceous plants from reflectance data obtained from ground-based and satellite-borne multi-spectral radiometry (MSR) units. We demonstrated the potential to estimate biomass of shrubs using the same approaches. We did not have time and resources to complete vegetation maps that would optimize estimates from remote sources, but we have outlined procedures that can be followed in the future to obtain biomass estimates at the landscape scale.

Wyoming↗

USGS2007

Factors Affecting the Occurrence and Distribution of Pesticides in the Yakima River Basin, Washington, 2000

The Yakima River Basin is a major center of agricultural production. With a cultivated area of about 450,000 ha (hectares), the region is an important producer of tree fruit, grapes, hops, and dairy products as well as a variety of smaller production crops. To control pest insects, weeds, and fungal infections, about 146 pesticide active ingredients were applied in various formulations during the 2000 growing season. Forty-six streams or drains in the Yakima River Basin were sampled for pesticides in July and October of 2000. Water samples also were collected from 11 irrigation canals in July. The samples were analyzed for 75 of the pesticide active ingredients applied during the 2000 growing season - 63 percent of the pesticides were detected. An additional 14 pesticide degradates were detected, including widespread occurrence of 2 degradates of DDT. The most frequently detected herbicide was 2,4-D, which was used on a variety of crops and along rights-of-way. It was detected in 82 percent of the samples collected in July. The most frequently detected insecticide was azinphos-methyl, which was used primarily on tree fruit. It was detected in 37 percent of the samples collected in July. All occurrences of azinphos-methyl exceeded the Environmental Protection Agency recommended chronic concentration for the protection of aquatic organisms. More than 90 percent of the July samples and 79 percent of the October samples contained two or more pesticides, with a median of nine in July and five in October. The most frequently occurring herbicides in mixtures were atrazine, 2,4-D, and the degradate deethylatrazine. The most frequently occurring insecticides in mixtures were azinphos-methyl, carbaryl, and p,p'-DDE (a degradate of DDT). A greater number of pesticides and higher concentrations were found in July than in October, reflecting greater usage and water availability for transport during the summer growing and irrigation season. Most of the samples collected in October (baseflow conditions) contained at least one pesticide. The mass ratio of instream pesticide load and application (pesticide loss) was used to explore spatial and temporal patterns of pesticide occurrence. Losses of pesticides with large organic carbon-water partitioning coefficients (Koc) values, which adhere strongly to sediment and plant surfaces, were smallest in catchments where sprinkler and drip irrigation systems were widely used. In contrast, losses of pesticides with low Koc values did not relate well with irrigation method.

Scientific Investigations Report↗

USGS2017

Wave dynamics and flooding on low-lying tropical reef-lined coasts

Many tropical islands and coasts are lined with coral reefs. These reefs are host to valuable ecosystems that support abundant marine species and provide resources for fisheries and recreation. As a flood defense, reefs protect coastlines from coastal storm damage and flooding by reducing the majority of incident wave energy. However, during storm and large swell conditions, coastal wave-driven flooding and overwash still occur due to high water levels, (infra) gravity waves, and/or low-frequency wave resonance. The wave and flooding effects cause erosion, damage to infrastructure, agricultural crops, and salinization of precious drinking water supplies. These impacts, which are likely to increase due to climate change and ongoing development on the islands, may cause many low-lying tropical islands and coastal areas to become uninhabitable before the end of the century. This paper investigates aspects of wave dynamics for the case of a small island in the tropical Pacific Ocean, shows projections of flooding under climate change scenarios, and outlines approaches to generalize the results to other islands, including mitigation options.

Conference Paper↗