Science Explorer
Exploring: Monitoring
Monitoring the pulse of our Nation's rivers and streams—The U.S. Geological Survey streamgaging network
In the late 1800s, John Wesley Powell, second Director of the U.S. Geological Survey (USGS), proposed gaging the flow of rivers and streams in the Western United States to evaluate the potential for irrigation. Around the same time, several cities in the Eastern United States established primitive streamgages to help design water-supply systems....
Effects of antecedent streamflow and sample timing on trend assessments of fish, invertebrate, and diatom communities
Detecting trends in biological attributes is central to many stream monitoring programs; however, understanding how natural variability in environmental factors affects trend results is not well understood. We evaluated the influence of antecedent streamflow and sample timing (covariates) on trend estimates for fish, invertebrate, and diatom taxa...
Pathology and case definition of Severe Perkinsea Infections of frogs
Severe Perkinsea infection (SPI) is an emerging disease of frogs responsible for mass mortalities of tadpoles across the United States. It is caused by protozoa belonging to the phylum Perkinsozoa that form a distinct group referred to as the Pathogenic Perkinsea Clade of frogs. In this work, we provide detailed description of gross and histologic...
Evaluating restored tidal freshwater wetlands
As restoration of tidal freshwater wetlands has progressed in North America and Eurasia, research findings have continued to emerge on the postrestoration success of these ecosystems. The most common approaches used to restore tidal freshwater wetlands involve excavation or placement of dredged sediment to restore tidal ...
Using acoustic Doppler velocity meters to estimate suspended sediment along the lower Minnesota and Mississippi Rivers
Lake Pepin is the largest naturally formed lake on the Mississippi River and has complex management needs to satisfy economic, environmental, and cultural demands. Lake Pepin is filling in with sediment at a rapid rate compared to conditions before settlement by European immigrants and intense agricultural cultivation. Accordingly, the Minnesota...
Identifying natural and anthropogenic variability of uranium at the well scale, Homestake Superfund site, near Milan, New Mexico, USA
The San Mateo Creek Basin in New Mexico, USA is located within the Grants Mineral Belt-an area with numerous uranium (U) ore deposits, mines, and milling operations. Six monitoring wells set in an alluvial aquifer near the Homestake Mining Co. Superfund site in the lower San Mateo Creek Basin were logged with a suite of borehole geophysical tools...
Patterning emergent marsh vegetation assemblages in coastal Louisiana, USA, with unsupervised artificial neural networks
QuestionAre self‐organizing maps (SOMs) useful for patterning coastal wetland vegetation communities? Do SOMs provide robust alternatives to traditional classification methods, particularly when underlying species response functions are unknown or difficult to approximate, or when a need exists to continuously classify new samples obtained under...
Seasonality of nitrate sources and isotopic composition in the Upper Illinois River
To improve understanding of spatial, seasonal, and inter-annual variations in nitrate sources and in-stream processes in the Illinois River system, nitrate concentrations and isotopic compositions were measured in 445 water samples collected over a four-year period (2004–2008) from the Upper Illinois River Basin (UIRB). Samples included surface...
Space-based imaging radar studies of U.S. volcanoes
The arrival of space-based imaging radar as a revolutionary land-surface mapping and monitoring tool little more than a quarter century ago enabled a spate of innovative volcano research worldwide. Soon after launch of European Space Agency’s ERS-1 spacecraft in 1991, the U.S. Geological Survey began SAR and InSAR studies of volcanoes in the...
Potential toxicity of complex mixtures in surface waters from a nationwide survey of United States streams: Identifying in vitro bioactivities and causative chemicals
While chemical analysis of contaminant mixtures remains an essential component of environmental monitoring, bioactivity-based assessments using in vitro systems increasingly play a role in the detection of biological effects. Historically, in vitro assessments focused on a few biological pathways, e.g., aryl hydrocarbon receptor (AhR) or estrogen...
Allowable take of black vultures in the eastern United States
Black vultures (Coragyps atratus) have been increasing in density and expanding their range in the eastern United States since at least the 1960s. In many areas, their densities have increased to the level where they are causing damage to property and livestock and the number of requests for allowable take permits has increased throughout these...
Movements of female Sage Grouse Centrocercus urophasianus during incubation recess
We combined GPS data‐loggers, VHF transmitters, and DVR video‐monitoring to measure fine‐scale movement patterns during daily incubation recesses by female Sage Grouse Centrocercus urophasianus, a species with uniparental incubation that has experienced widespread population decline and distributional contraction. Most (69.6%) Sage Grouse...
Explaining harvests of wild-harvested herbaceous plants: American ginseng as a case study
Wild-harvested plants face increasing demand globally. As in many fisheries, monitoring the effect of harvesting on the size and trajectory of resource stocks presents many challenges given often limited data from disparate sources. Here we analyze American ginseng (Panax quinquefolius L.) harvests from 18 states in the...
Insights into the mechanisms of phreatic eruptions from continuous high frequency volcanic gas monitoring: Rincón de la Vieja volcano, Costa Rica
Understanding the trigger mechanisms of phreatic eruptions is key to mitigating the effects of these hazardous but poorly forecastable volcanic events. It has recently been established that high-rate volcanic gas observations are potentially very suitable to identifying the source processes driving phreatic eruptions, and to eventually detecting...
Linkages between hydrology and seasonal variations of nutrients and periphyton in a large oligotrophic subalpine lake
Periphyton is important to lake ecosystems, contributing to primary production, nutrient cycling, and benthic metabolism. Increases in periphyton growth in lakes can be indicative of changes in water quality, shifts in ecosystem structure, and increases in nutrient fluxes. In oligotrophic lakes, conservationists are interested in characterizing...
A bibliometric profile of the Remote Sensing Open Access Journal published by MDPI between 2009 and 2018
Remote Sensing Open Access Journal (RS OAJ) is an international leading journal in the field of remote sensing science and technology. It was first published in the year 2009 and is currently celebrating tenth year of publications. In this research, a bibliometric analysis of RS OAJ was conducted based on 5588 articles published during the 10-year...
The formation of gullies on Mars today
A decade of high-resolution monitoring has revealed extensive activity in fresh Martian gullies. Flows within the gullies are diverse: they can be relatively light, neutral or dark, colourful or bland, and range from superficial deposits to 10 m-scale topographic changes. We observed erosion and transport of material within gullies, new terraces,...