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At least 1,711 records · Page 95Linked to original sources

Relation of trihalomethane-formation potential to water-quality and physical characteristics of small water-supply lakes, eastern Kansas

The formation of carcinogenic trihalomethanes during the treatment of public surface water supplies has become a potentially serious problem. The U. S. Geological Survey, in cooperation with the Kansas Department of Health and Environment , investigated the potential for trihalomethane formation in water from 15 small, public water supply lakes in eastern Kansas from April 1984 through April 1986 in order to define the principal factors that affect or control the potential for trihalomethane formation during the water treatment process. Relations of mean concentrations of trihalomethane-formation potential to selected water quality and lake and watershed physical characteristics were investigated using correlation and regression analysis. Statistically significant, direct relations were developed between trihalomethanes produced in unfiltered and filtered lake water and mean concentrations of total and dissolved organic carbon. Correlation coefficients for these relations ranged from 0.86 to 0.93. Mean values of maximum depth of lake were shown to have statistically significant inverse relations to mean concentrations of trihalomethane-formation potential and total and dissolved organic carbon. Correlation coefficients for these relations ranged from -0.76 to -0.81.

Kansas↗

Inland waters

1. The total flux of carbon—which includes gaseous emissions, lateral flux, and burial—from inland waters across the conterminous United States (CONUS) and Alaska is 193 teragrams of carbon (Tg C) per year. The dominant pathway for carbon movement out of inland waters is the emission of carbon dioxide gas across water surfaces of streams, rivers, and lakes (110.1 Tg C per year), a flux not identified in the First State of the Carbon Cycle Report (SOCCR1; CCSP 2007). Second to gaseous emissions are the lateral fluxes of carbon through rivers to coastal environments (59.8 Tg C per year). Total carbon burial in lakes and reservoirs represents the smallest flux for CONUS and Alaska (22.5 Tg C per year) (medium confidence). 2. Based on estimates presented herein, the carbon flux from inland waters is now understood to be four times larger than estimates presented in SOCCR1. The total flux of carbon from inland waters across North America is estimated to be 507 Tg C per year based on a modeling approach that integrates high-resolution U.S. data and continental-scale estimates of water area, discharge, and carbon emissions. This estimate represents a weighted average of 24 grams of carbon per m2 per year of continental area exported and removed through inland waters in North America (low confidence). 3. Future research can address critical knowledge gaps and uncertainties related to inland water carbon fluxes. This chapter, for example, does not include methane emissions, which cannot be calculated as precisely as other carbon fluxes because of significant data gaps. Key to reducing uncertainties in estimated carbon fluxes is increased temporal resolution of carbon concentration and discharge sampling to provide better representations of storms and other extreme events for estimates of total inland water carbon fluxes. Improved spatial resolution of sampling also could potentially highlight anthropogenic influences on the quantity and quality of carbon fluxes in inland waters and provide information for land-use planning and management of water resources. Finally, uncertainties could likely be reduced if the community of scientists working in inland waters establishes and adopts standard measurement techniques and protocols similar to those maintained through collaborative efforts of the International Ocean Carbon Coordination Project and relevant governmental agencies from participating nations.

Book chapter↗

Carbon sequestration potential estimates with changes in land use and tillage practice in Ohio, USA

Soil C sequestration through changes in land use and management is one of the important strategies to mitigate the global greenhouse effect. This study was conducted to estimate C sequestration potential of the top 20 cm depth of soil for two scenarios in Ohio, USA: (1) with reforestation of both current cropland and grassland where SOC pools are less than the baseline SOC pool under current forest; (2) with the adoption of NT on all current cropland. Based on Ohio Soil Survey Characterization Database and long-term experimental data of paired conservation tillage (CT) versus no-till (NT), we specified spatial variations of current SOC pools and C sequestration potentials associated with soil taxa within each major land resource area (MLRA). For scenario I, there would be 4.56 Mha of cropland having an average SOC sequestration capacity of 1.55 kg C m −2 and 0.80 Mha of grassland with that of 1.35 kg C m −2 . Of all potential area, 73% are associated with Alfisols and 15% with Mollisols, but the achievable potential could vary significantly with individual MLRAs. Alternately, an average SOC sequestration rate of 62 g C m −2 year −1 was estimated with conversion from CT to NT for cultivated Alfisols, by which a cumulative increase of 71 Tg C resulted from reforestation of cropland could be realized in 25 years. Soils with lower antecedent C contents have higher C sequestration rates. In comparison with the results obtained at the state scale, the estimates of SOC sequestration potentials taxonomically associated with each specific MLRA may be more useful to the formulation of C credit trading programs.

Agriculture, Ecosystems and Environment↗

Conserving transboundary wildlife migrations: Recent insights from the Greater Yellowstone Ecosystem

Animal migrations are ecologically, culturally, and economically important. Ungulate populations in many parts of Africa, Asia, Europe, and the Americas migrate long distances to access seasonally available resources, traversing vast landscapes in large numbers. Yet some migrations are declining, raising concerns among scientists and natural resource managers. We synthesize recent advances in ungulate migration ecology with relevance to management and policy. Using case studies from the Greater Yellowstone Ecosystem (GYE), we show how new tools can be applied to map ungulate migrations and assess threats across multiple seasonal habitats, serving as a conservation roadmap. To help conserve ungulate migrations, we also propose a transboundary science, policy, and management framework that could be adapted beyond the GYE and that encompasses the needs of multiple species. The key elements of this framework consist of more widespread mapping and assessment of migrations, improved federal and state coordination across jurisdictional lines, increased investment in private land conservation, and strong engagement of local stakeholders positioned to sustain conservation activities over the long term.

Idaho, Montana, Wyoming↗

Drought and deluge— Opportunities for climate-change adaptation in US national parks

In a changing climate, resource management depends on anticipating changes and considering uncertainties. To facilitate effective decision making on public lands, we regionally summarized the magnitude and uncertainty of projected change in management-relevant climate variables for 332 national park units across the contiguous US. Temperature, frequency of extreme precipitation events, and drought exposure are all projected to increase within seven regions delineated in the US National Climate Assessment. In particular, the anticipated collective impacts of droughts and flooding events will lead to unique management challenges, including combinations of management actions that may seem inconsistent. Furthermore, uncertainty in the magnitude of change varied by region and climate variable considered, pointing to specific opportunities for prioritization, transferability, and innovation of climate adaptation regionally and at the park-unit scale.

conterminous United States↗

Unmanned aircraft systems (UAS) activities at the Department of the Interior

The U.S. Department of the Interior (DOI) is responsible for protecting and managing the natural resources and heritage on almost 20% of the land in the United States. The DOI’s mission requires access to remotely sensed data over vast lands, including areas that are remote and potentially dangerous to access. Unmanned Aircraft Systems (UAS) technology has the potential to enable the DOI to be a better steward of the land by: (1) Improving natural hazard forecasting and the analysis of the impacts. (2) Improving the understanding of climate change to better plan for likely impacts. (3) Developing precipitation and evaporation forecasting to better manage water resources. (4) Monitoring Arctic ice change and its impacts on ecosystems, coasts, and transportation. (5) Increasing safety and effectiveness of wildland fire management. (6) Enhancing search and rescue capabilities. (7) Broadening the abilities to monitor environmental or landscape conditions and changes. (8) Better understanding and protecting the Nation’s ecosystems. The initial operational testing and evaluations performed by the DOI have proven that UAS technology can be used to support many of the Department’s activities. UAS technology provides scientists a way to look longer, closer and more frequently at some of Earth’s most remote areas—places that were previously too dangerous or expensive to monitor in detail. The flexibility of operations and relative low cost to purchase and operate Small Unmanned Aerial System (sUAS) enhances the ability to track long-term landscape and environmental change. The initial testing indicates the operational costs are approximately 10% of traditional manned aircraft. In addition, users can quickly assess landscape-altering events such as wildland fires, floods and volcanoes. UAS technology will allow the DOI to do more with less and in the process enhance the Department’s ability to provide unbiased scientific information to help stakeholders make informed decisions. It will also provide a digital baseline record that can be archived and used when monitoring future events or conditions. One possible future scenario has scientists carrying sUAS into the field allowing quick deployment and operation to observe the environment or for emergency response. This scenario could also include a persistent monitoring capability provided by a UAS that can stay airborne over a small geographic area for days or weeks, or possibly longer. While the DOI focus is on sUAS, the Department recognizes that larger UAS systems will also play a role in meeting its mission. The Department anticipates meeting long-duration or specialized acquisition commitments, such as state or national aerial photography, by collaboration with other agencies or through commercial contracts. Even though the DOI continues to evaluate UAS and sensor technology to meet the Department’s mission, some of its bureaus are already moving towards an operational capability. The authors fully anticipate that by 2020 UAS will emerge as one of the primary platforms for DOI remote sensing applications.

Photogrammetric Engineering and Remote Sensing↗

Space-based monitoring of penguin diet links sea ice, food webs, and population change

Rapid environmental change is reshaping Antarctic ecosystems through shifts in temperature and sea ice dynamics, with implications for species such as the iconic Adélie penguin ( Pygoscelis adeliae ). Because Antarctic predators rely on a relatively small number of key prey resources in the region 1 whose life histories are intrinsically linked to sea ice, 2 , 3 these abiotic changes are expected to cascade through food webs. However, the scale and remoteness of Antarctica have limited efforts to link environmental change to ecological responses across the continent. Combining tools from imaging spectroscopy, stable isotope analysis, and hierarchical statistical modeling, we reconstructed Adélie penguin diet across the entirety of the species’ global range over a three-decade period (1984–2013) using satellite imagery from the Landsat program. This approach leveraged the distinct spectral properties (a generalized measure of color) of penguin guano as observed by satellites, 4 , 5 which vary according to penguin diet. 6 , 7 We found pronounced differences in diet across the continent and that year-to-year dietary shifts were strongly associated with sea ice dynamics. Higher sea ice corresponded to more fish-based diets, whereas lower sea ice was associated with a greater reliance on krill. Additionally, spatial differences in penguin diet were associated with long-term trends in penguin abundance, linking food web processes to large-scale population dynamics. This study represents the first use of satellite observations to capture trophic dynamics at continental and decadal scales and highlights how environmental change might restructure Antarctic food webs and influence the future of a key sentinel species.

Current Biology↗

Vegetation community recovery on restored bottomland hardwood forests in northeast Indiana, USA

Vegetation communities in restored bottomland hardwood forests in northeast Indiana were studied 6–21 years after restoration to assess progress toward restoration objectives. The study focused on four sites that were restored to compensate for resource injuries after contaminant releases. The restored sites were compared with four reference-site conditions, including crops (prerestoration condition), old field communities representing a no-management alternative, locally sampled second-growth mature forests, and forest community types described by the US National Vegetation Classification (USNVC), which represent ideal or defining conditions of recognized vegetation communities. Fixed-area plots provided data on field-sampled environmental variables, vegetation, soil, and hydrological conditions for crops, old fields, restored areas, and mature forests. The USNVC database provided quantitative data for three historically and geographically relevant reference forest community types for comparison with the sampled communities. Results of nonmetric multidimensional scaling based on species cover revealed clear gradients relating to site age and canopy development. Along those gradients, restored areas demonstrated increasing similarity to mature forest reference communities in terms of floristic composition. Specifically, the floristic quality of restored areas was significantly greater than that of crops and old fields. Furthermore, soil health measurements of physical, chemical, and hydrological conditions indicated significant improvements in restored site soils compared with prerestoration conditions represented by cropland soils. Descriptions and data from the USNVC provided ecological context for restoration target conditions and facilitated the assessment of restoration recovery along a trajectory from starting conditions to those target conditions. Descriptions by USNVC also helped identify deviations from the intended restoration objectives (e.g., invasive species recruitment) and potential adaptive management actions to return sites to their intended trajectories. Integr Environ Assess Manag 2024;00:1–22. Published 2024. This article is a U.S. Government work and is in the public domain in the USA. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Indiana↗

Statewide summary for Alabama

Alabama is over 132,000 km 2 (51,000 miles 2 ) in area, 483 km (300 miles) long, and 322 km (200 miles) wide (Copeland, 1968). Coastal Alabama comprises Mobile and Baldwin Counties and the surrounding State waters in the Gulf of Mexico (Figure 1; O’Neil and Mettee, 1982). It is part of both the East Gulf Coastal Plain section of the Coastal Plain province and the Mississippi-Alabama shelf section of the Continental Shelf province. Within the East Gulf Coastal Plain section, Alabama’s coastal land falls within the Southern Pine Hills and Coastal Lowlands subdivisions. The Southern Pine Hills subdivision is a sloping landscape composed of sand and clay. Its elevation varies from approximately 30 m (98 ft) near the coast to over 90 m (295 ft) in the northern areas of the two coastal counties. The Coastal Lowlands subdivision is a flat to slightly undulating plain with creeks, rivers, estuaries, and marshes leading to the surrounding bays and the Gulf of Mexico. Offshore Alabama is part of the Mississippi-Alabama section of the Continental Shelf. Barrier islands and spits in coastal Alabama include Dauphin Island, Fort Morgan Peninsula, and Perdido Key. Dauphin Island consists of a beach with dunes on the Gulf side and beaches and marshes on the north side. It was once over 24 km long, but after Hurricane Katrina it has been broken into two distinct islands. Fort Morgan Peninsula is attached to the eastern mainland and extends westward between Mobile Bay and the Gulf of Mexico. A large beach exists on the gulf side, with numerous lagoons and marshes on the bayside. Perdido Key is a narrow peninsula on the easternmost Alabama coast near the Alabama-Florida border, south of Perdido Bay. It consists of beaches and high dunes, with some marshes on the lagoon side of the peninsula. Mobile Bay, parts of Mississippi Sound, Perdido Bay, and many smaller rivers and streams are the main bodies of water in coastal Alabama. Mobile Bay, a submerged river valley, is the largest at 1,070 km 2 (413 miles 2 ) in area and 51.5 km (32 miles) in length (Mobile Bay NEP, 2008). Mobile Bay is 37 km (23 miles) wide at its maximum width near the opening to the Gulf of Mexico at the south end of the bay, and 16.1 km (10 miles) wide at the city of Mobile (Mobile Bay NEP, 2003; Mobile Bay NEP, 2008). It is remarkably shallow with an average depth of 3 m (10 ft), yet it discharges approximately 1,755.6 m 3 (62,000 ft 3 ) of water every second on average (Mobile Bay NEP, 2008). Mississippi Sound runs parallel to the coasts of Mississippi and part of Alabama. The length of the Alabama portion of Mississippi Sound is approximately 26 km (16.2 miles) from the Dauphin Island bridge to the Mississippi-Alabama State line (O’Neil and Mettee, 1982). Dauphin Island separates the sound from the Gulf of Mexico. The sound drains into the Gulf of Mexico west of Dauphin Island at Petit Bois Pass, which is approximately 8 km (5 miles) wide. Mississippi Sound averages approximately 3.5 m (11.5 ft) in depth. Salt marshes, large areas of wetland scrub-shrub, and tidal creeks characterize the northern shore of Mississippi Sound, and the southern shore is composed of sandy barrier islands. Perdido Bay is located at the boundary of Baldwin County and Florida’s Escambia County. It is approximately 27 km (16.8 miles) long, 5 km (3 miles) at its widest point, and, on average, 2.4 m (7.9 ft) deep. The major fresh-water resource in coastal Alabama is the Mobile River, formed by the confluence of the Alabama and Tombigbee Rivers. The watershed for the Mobile River is approximately 111,369 km 2 (43,000 miles 2 ) large and includes parts of Alabama, Georgia, Mississippi, and Tennessee (Handley et al., 2007). Parts of Alabama and the Florida Panhandle drain into the Perdido River basin and western coastal Alabama drains into the Escatawpa River. Emergent wetlands offer valuable ecological services in coastal Alabama. Marshes provide extensive plant material, which provides energy to the detritus-based estuarine ecological system (O’Neil et al., 1983). They provide habitat for many organisms, including shrimp and crabs, whose harvest is a major industry in coastal Alabama. Marshes provide habitat for refuge, feeding, breeding, and spawning. They also remove excess nutrients from water and contribute to erosion control. Degradation of marshes by pollutants, sediments, and other impacts decreases productivity of the entire estuarine ecosystem. Among the nation’s states, Alabama ranks fifth in number of different species (144 endemic species), second in number of extinctions that have already occurred (90 extinct species) and fourth in number of species at risk for extinction (14.8% at risk out of 4,533 total species; Stein, 2002). Many species of wildlife benefit from the wetland habitats in coastal Alabama. Numerous bird species can be found in coastal Alabama emergent marshes, which provide habitat for shore- and wading-birds that inhabit salt or brackish water coastal environments (Anderson et al., 1981). Colonial seabirds nest on coastal Alabama’s islands, the mainland, and dredge disposal sites (Cooley, 1987). The Mobile-Tensaw Delta and Mobile Bay are the state’s primary migratory waterfowl coastal wintering areas (U.S. Fish and Wildlife Service, 1982). The shallow waters, abundance of fish, and vegetative cover in emergent marsh contribute to excellent waterfowl habitat. Emergent wetlands in Alabama also provide habitat for a multitude of endangered species, including various species of raptors and wading- and shorebirds (O’Neil et al., 1983).

Alabama↗

The role of groundwater transport in aquatic mercury cycling

Mercury, which is transported globally by atmospheric pathways to remote aquatic environments, is a ubiquitous contaminant at very low (nanograms Hg per liter) aqueous concentrations. Until recently, however, analytical and sampling techniques were not available for freshwater systems to quantify the actual levels of mercury concentrations without introducing significant contamination artifacts. Four different sampling strategies were used to evaluate ground water flow as a mercury source and transport mechanism within aquatic systems. The sampling strategies employ ultraclean techniques to determine mercury concentrations in groundwater and pore water near Pallette Lake, Wisconsin. Ambient groundwater concentrations are about 2–4 ng Hg L −1 , whereas pore waters near the sediment/water interface average about 12 ng Hg L −1 , emphasizing the importance of biogeochemical processes near the interface. Overall, the groundwater system removes about twice as much mercury (1.5 g yr −1 ) as it contributes (0.7 g yr −1 ) to Pallette Lake. About three fourths of the groundwater mercury load is recycled, thought to be derived from the water column.

Wisconsin↗

Herbicides and transformation products in surface waters of the Midwestern United States

Most herbicides applied to crops are adsorbed by plants or transformed (degraded) in the soil, but small fractions are lost from fields and either move to streams in overland runoff, near surface flow, or subsurface drains, or they infiltrate slowly to ground water. Herbicide transformation products (TPs) can be more or less mobile and more or less toxic in the environment than their source herbicides. To obtain information on the concentrations of selected herbicides and TPs in surface waters of the Midwestern United States, 151 water samples were collected from 71 streams and five reservoir outflows in 1998. These samples were analyzed for 13 herbicides and 10 herbicide TPs. Herbicide TPs were found to occur as frequently or more frequently than source herbicides and at concentrations that were often larger than their source herbicides. Most samples contained a mixture of more than 10 different herbicides or TPs. The ratios of TPs to herbicide concentrations can be used to determine the source of herbicides in streams. Results of a two-component mixing model suggest that on average 90 percent or more of the herbicide mass in Midwestern streams during early summer runoff events originates from the runoff and 10 percent or less comes from increased ground water discharge.

Journal of the American Water Resources Associatio↗

Preservation of samples for dissolved mercury

Water samples for dissolved mercury requires special treatment because of the high chemical mobility and volatility of this element. Widespread use of mercury and its compounds has provided many avenues for contamination of water. Two laboratory tests were done to determine the relative permeabilities of glass and plastic sample bottles to mercury vapor. Plastic containers were confirmed to be quite permeable to airborne mercury, glass containers were virtually impermeable. Methods of preservation include the use of various combinations of acids, oxidants, and complexing agents. The combination of nitric acid and potassium dichromate successfully preserved mercury in a large variety of concentrations and dissolved forms. Because this acid-oxidant preservative acts as a sink for airborne mercury and plastic containers are permeable to mercury vapor, glass bottles are preferred for sample collection. To maintain a healthy work environment and minimize the potential for contamination of water samples, mercury and its compounds are isolated from the atmosphere while in storage. Concurrently, a program to monitor environmental levels of mercury vapor in areas of potential contamination is needed to define the extent of mercury contamination and to assess the effectiveness of mercury clean-up procedures.Water samples for dissolved mercury require special treatment because of the high chemical mobility and volatility of this element. Widespread use of mercury and its compounds has provided many avenues for contamination of water. Two laboratory tests were done to determine the relative permeabilities of glass and plastic sample bottles to mercury vapor. Plastic containers were confirmed to be quite permeable to airborne mercury, glass containers were virtually impermeable. Methods of preservation include the use of various combinations of acids, oxidants, and complexing agents. The combination of nitric acid and potassium dichromate successfully preserved mercury in a large variety of concentrations and dissolved forms.

Water Resources Bulletin↗

Nodal seismic deployment on Mauna Loa volcano, Hawaii: Dataset and preliminary insights

Mauna Loa is the largest active volcano on Earth, comprising ∼51% of the Island of Hawai‘i’s landmass and posing significant risks to the island’s communities, infrastructure, and natural environment. Historical eruptions have produced lava flows that have reached the ocean in as little as 3 hr. The timing and location of such lava flows in the past 200 yr underscore how critical determination of the location and geometry of magma storage and structure is for volcanic hazard assessment and eruption forecasting. Now, after nearly 38 yr of volcanic quiescence, Mauna Loa has erupted again. On 27 November 2022, fissures initiated within the summit caldera and then migrated to the northeast rift zone, where they generated a large lava flow that threatened a major highway. To improve our understanding of the geometry of this magma system, we deployed a temporary nodal array on Mauna Loa in the summer of 2024. This increased our seismic coverage sufficiently to image this magmatic system. This nodal array consists of 33 seismometers distributed on and around the volcano and was deployed for over three months to record seismic signals. The primary objective of this project is to resolve the high‐resolution seismic velocity structure and characterize seismic features associated with magma storage and ascent pathways. In this article, we present an overview of the deployment, evaluate the quality of the data, and show example recordings to evaluate the suitability of the data set for future seismic investigations, including earthquake relocation, seismic tomography, and receiver function analysis. Comparisons with nearby permanent broadband and short‐period seismic stations demonstrate that the nodal array recorded high‐quality waveforms, making it a valuable resource for constraining the magmatic system beneath Mauna Loa at multiple scales.

Hawaii↗

Review of Oceanographic and Geochemical Data Collected in Massachusetts Bay during a Large Discharge of Total Suspended Solids from Boston's Sewage-Treatment System and Ocean Outfall in August 2002

During the period August 14-23, 2002, the discharge of total suspended solids (TSS) from the Massachusetts Water Resources Authority sewage-treatment plant ranged from 32 to 132 milligrams per liter, causing the monthly average discharge to exceed the limit specified in the National Pollution Discharge Elimination System permit. Time-series monitoring data collected by the U.S. Geological Survey in western Massachusetts Bay were examined to evaluate changes in environmental conditions during and after this exceedance event. The rate of sediment trapping and the concentrations of near-bottom suspended sediment measured near the outfall in western Massachusetts Bay increased during this period. Because similar increases in sediment-trapping rate were observed in the summers of 2003 and 2004, however, the increase in 2002 cannot be definitively attributed to the increased TSS discharge. Concentrations of copper and silver in trapped sediment collected 10 and 20 days following the 2002 TSS event were elevated compared to those in pre-event samples. Maximum concentrations were less than 50 percent of toxicity guidelines. Photographs of surficial bottom sediments obtained before and after the TSS event do not show sediment accumulation on the sea floor. Concentrations of silver, Clostridium perfringens, and clay in surficial bottom sediments sampled 10 weeks after the discharge event at a depositional site 3 kilometers west of the outfall were unchanged from those in samples obtained before the event. Simulation of the TSS event by using a coupled hydrodynamic-wave-sediment-transport model could enhance understanding of these observations and of the effects of the exceedance on the local marine environment.

Open-File Report↗

Human-polar bear interactions

Human-wildlife interactions (HWI) are driven fundamentally by overlapping space and resources. As competition intensifies, the likelihood of interaction and conflict increases. In turn, conflict may impede conservation efforts by lowering social tolerance of wildlife, especially when human-wildlife conflict (HWC) poses a threat to human safety and economic well-being. Thus, mitigating conflict is one of the most consequential components of a wildlife management program, particularly for large carnivores. However, unlike other large carnivores, the causative factors and conservation consequences of interactions between humans and polar bears ( Ursus maritimus ) are poorly understood. Historically, mitigation of human-polar bear conflict has been a low management priority with the exception of a few locations where conflict had been a chronic concern. In part, this was because of low human densities in most of the Arctic and sea ice act as a physical barrier regulating the frequency of human-polar bear interactions. However, as the Arctic has warmed, anthropogenic activities have increased, and polar bears have become more reliant on land. As a result, mitigating interaction and conflict between humans and polar bears has become a growing concern. In this chapter, we explore the nexus of polar bear and human behavior and environmental change in driving the nature and intensity of human-polar bear interaction and conflict. We first provide an overview of behaviors that contribute to the occurrence of interactions and conflicts. We then review historical and contemporary drivers of interaction and conflict and examine how climate-mediated changes to Arctic marine and terrestrial environments are likely to influence distribution and types of future incidents. We close by proposing a conceptual framework that conservationists and managers can use to mitigate the likelihood of future human-polar bear conflict in a rapidly changing Arctic.

Book chapter↗

A social–ecological perspective for riverscape management in the Columbia River Basin

Riverscapes are complex, landscape-scale mosaics of connected river and stream habitats embedded in diverse ecological and socioeconomic settings. Social–ecological interactions among stakeholders often complicate natural-resource conservation and management of riverscapes. The management challenges posed by the conservation and restoration of wild salmonid populations in the Columbia River Basin (CRB) of western North America are one such example. Because of their ecological, cultural, and socioeconomic importance, salmonids present a complex management landscape due to interacting environmental factors (eg climate change, invasive species) as well as socioeconomic and political factors (eg dams, hatcheries, land-use change, transboundary agreements). Many of the problems in the CRB can be linked to social–ecological interactions occurring within integrated ecological, human–social, and regional–climatic spheres. Future management and conservation of salmonid populations therefore depends on how well the issues are understood and whether they can be resolved through effective communication and collaboration among ecologists, social scientists, stakeholders, and policy makers.

Columbia River Basin↗

Minnesota landowners’ trust in their department of natural resources, salient values similarity and wildlife value orientations

Due to extensive land conversion over the last century, much of the native prairie pothole ecosystem has been converted to agricultural or other human uses. The prairie pothole ecosystem is found in the northern plains of Iowa, Minnesota, South Dakota, North Dakota, and Montana. Because most of the land in this region is privately owned and used for agricultural production, most impacts to wildlife habitat are the result of decisions by individual landowners. Landowner trust in natural resource management agencies is important for agencies to effectively accomplish their mission. We measured the nature (competence and fairness) and level of trust that western Minnesota landowners have in the Minnesota Department of Natural Resources (MnDNR) and landowners’ wildlife value orientations (WVO). Landowners rated MnDNR slightly higher in competence than fairness; however, these two dimensions were strongly correlated. We developed a MnDNR trust scale (six items) and a three-cluster model dividing landowners along the MnDNR trust scale, which we named Negative (28%), Neutral (43%), and Positive (29%). We provide evidence supporting the salient values similarity (SVS) model that states people have trust in agencies holding similar values; landowners reporting greater importance for wildlife consideration when making land-use decisions also reported greater trust in the MnDNR. In addition, mutualist landowners had the highest trust in the MnDNR and utilitarian landowners the lowest level of trust, which is opposite of the trust relationship reported for the general public with state wildlife agencies. Based on the SVS model, our results suggest that mutualist landowners perceive greater congruence with MnDNR goals related to wildlife habitat compared to utilitarian landowners.

Minnesota↗

Ground-water levels and direction of ground-water flow in the central part of Bernalillo County, New Mexico, summer 1983

In 1980, toxic chemicals were detected in water samples from wells in and near Albuquerque 's San Jose well field. At the request of the Environmental Improvement Division of the New Mexico Health and Environment Department, the U.S. Geological Survey conducted a study to determine groundwater levels and flow direction. Water levels were measured in 44 wells in a 64 sq mi area along the Rio Grande and adjacent areas during a period of near maximum municipal pumpage. Based on the altitude of screened interval, wells were grouped into shallow (screened internal above an altitude of 4,800 ft) or deep (screened internal below an altitude of 4,800 ft) zones. Groundwater in the shallow zone generally moves from north to south parallel to flow in the Rio Grande. Groundwater in the deep zone generally moves from the northwest to the east and southeast. A poorly developed cone of depression within the deep zone was present in the northeast. Water levels in wells were as much as 18 feet higher in the shallow zone than in the deep zone in the vicinity of the San Jose well field, indicating a downward gradient. (Author 's abstract)

Water-Resources Investigations Report↗