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Executive SummaryOn June 24, 2019, Congressman Raul Grijalva of Arizona, Chair of the House Committee on Natural Resources, sent a letter to the directors of the U.S. Fish and Wildlife Service and the U.S. Geological Survey to request their assistance in answering questions regarding coastal sediment resource management within the...

Decreased availability of forage, as well as increased pesticide exposure, are important factors in the decline of honey bee health. Here, we isolate land cover transitions and their effect on honey production at 160 commercial apiaries in the Northern Great Plains. We found that land cover changes from 2008 to...

Understanding groundwater flow and pumping effects near pending mining operations requires accurate subsurface hydraulic characterization. To improve conceptual models of groundwater flow and development in the complex hydrogeologic system near Long Canyon Mine, in northwestern Goshute Valley, northeastern Nevada, the U.S. Geological Survey characterized the hydraulic properties of carbonate...

Water radiolysis continuously produces H2 and oxidized chemicals in wet sediment and rock. Radiolytic H2 has been identified as the primary electron donor (food) for microorganisms in continental aquifers kilometers below Earth’s surface. Radiolytic products may also be significant for sustaining life in subseafloor sediment and subsurface environments...

Many questions relevant to conservation decision making are characterized by extreme uncertainty due to lack of empirical data and complexity of the underlying ecological processes, leading to a rapid increase in the use of structured protocols to elicit expert knowledge. Published ecological applications often employ a modified Delphi method, where...

Carbon dioxide (CO2) mixed into water is being explored as a possible management strategy to deter the upstream movements of invasive carps through navigation locks and other migratory pinch-points. This study used two-dimensional acoustic telemetry to assess the effectiveness of dissolved CO2 as a chemosensory deterrent to two carp species in...

In the U.S., 525,000 horseshoe crabs (Limulus polyphemus) per year have been captured during 2013–2017, brought to biomedical facilities, and bled to produce Limulus amebocyte lysate (LAL), then mostly released to the area of capture. The Atlantic States Marine Fisheries Commission estimates short-term bleeding-induced mortality to be 15% (4% to...

Many at-risk species lack standardized surveys across their range or quantitative data capable of detecting demographic trends. As a result, extinction risk assessments often rely on ordinal categories of risk based on explicit criteria or expert elicitation. This study demonstrates a...

Carbon dioxide (CO2) has been approved by the US Environmental Protection Agency as a new aquatic pesticide to control invasive Asian carps and other aquatic nuisance species in the United States. However, limited CO2 toxicity data could make it challenging for resource managers to characterize the potential risk to nontarget species...

This report documents methodology and results of a study that estimated groundwater discharge by evapotranspiration (GWET) from phreatophytic vegetation in two desert riparian areas with ephemeral spring discharge in Clark County, southern Nevada. The phreatophytes consisted primarily of western honey mesquite [Prosopis glandulosa var. torreyana (L.D. Benson) M.C. Johnst.] at Stump Spring and...

Native freshwater mussels are a guild of benthic, filter feeding invertebrates that perform important ecological functions in rivers. Because of their long lifespans (30–50 years or longer), mussels are slow to respond to human‐induced alterations. Thus, development of sensitive indicators of mussel population responses to river conditions and management would...

No abstract available....

A potentiometric-surface map for spring 2018 was created for the Mississippi River Valley alluvial (MRVA) aquifer using available groundwater-altitude data from 1,126 wells completed in the MRVA aquifer and from the altitude of the top of the water surface in area rivers from 66 streamgages. Personnel from Arkansas Natural Resources...

No abstract available....

No abstract available....

Decision structuring, also known as decision framing, provides the foundation and roadmap for analyzing a decision. For decisions that warrant a systematic approach, structuring begins with identifying the problem for analysis, which sounds simple but can be deceptively difficult because decision problems are often ill-formed at the start....

Predicting the consequences of alternative actions in terms of the objectives is central to decision making. Modeling in the broadest sense, from simple to complex and based on data or expert judgment, comprises the essential toolkit for making decision-relevant predictions. Gaps in knowledge and the resulting uncertainty can...

To be effective, managers of imperiled species must face the unavoidable tradeoff between conservation benefits and constrained budgets and must not be paralyzed by scientific uncertainty. Decision analysis can help meet these challenges when used to develop cost-effective strategies to recover or improve the status of species. The U.S. Fish...

The success of wildlife reintroduction efforts rests on the demographic performance of released animals. Whooping Cranes in the eastern migratory population—reintroduced beginning in 2001—demonstrate adequate survival but poor reproduction. Managers and scientists have used an iterative process of learning and management to respond to this management challenge, but by 2015,...

Conserving species requires managing threats, including habitat loss. One approach to managing habitat loss is to identify and protect habitat in networks of reserves. Reserve network design is a type of resource allocation problem: how can we choose the most effective reserve network design given available resources? We undertook development...

The collective set of decisions involved with the restoration of degraded wetlands is often more complex than considering only ecological responses and outcomes. Restoration is commonly driven by a complex interaction of social, economic, and ecological factors representing the mandate of resource stewards and the values of stakeholders. The authors...

American horseshoe crabs (Limulus polyphemus) have varied migration patterns and harvesting pressure throughout their range, potentially leading to regional differences in population dynamics. Here, a multi-state mark–recapture model was used to estimate annual survival and exchange rates of adult horseshoe crabs across three geographic regions in Long Island, NY (South...

The Sahara in North Africa and the Gobi and Taklamakan deserts in Asia are the primary sources of mobilized dust in the atmosphere, with regional or global airborne transport estimated at 2 to 5 billion tonnes per year. Annual Asian dust plumes take about 7 to 10 d to cross the...

Culturable eubacterial isolates were collected at various altitudes in Earth’s atmosphere to include ~1.5 m above ground in Tallahassee, Florida, USA, ~10.0 m above sea level over the mid-Atlantic ridge (~15oN), ~ 20 km above ground over the continental United States, ~20 km above sea level over the Pacific Ocean...

Between 2007 and 2013, the U.S. Geological Survey conducted a low-density (1 site per 1,600 square kilometers, 4,857 sites) geochemical and mineralogical survey of soils in the conterminous United States. The sampling protocol for the national-scale survey included, at each site, a sample from a depth of 0 to 5...