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New geochemical, U-Pb geochronology, and Sr-Nd-Hf isotope data provide evidence for the tectonic evolution of the Seventymile terrane in interior Alaska, USA. Ultramafic and mafic rocks of the Seventymile terrane are thought to represent components of a dismembered ophiolite and provide unique constraints on regional terrane evolution and accretion. The...

Mining-related contaminants such as selenium (Se) and mercury (Hg) accumulate in aquatic organisms and transfer through aquatic food webs, where they can exert toxic effect undermining the ecological health of aquatic resources. Yet, how Se and Hg co-distribute within food webs and within individual organisms remains poorly understood. We compiled...

Extensive mortalities of adult coho salmon (Oncorhynchus kisutch), often called “Urban Runoff Mortality Syndrome” (URMS), have been documented during the fall in creeks where water quality has been degraded by roadway runoff. The primary cause of mortality is 6PPD-quinone (6PPDQ; N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine quinone)–an ozone transformation product that forms on...

Distinguishing stream metal loading caused by mine features from that caused by natural background sources remains challenging, yet this distinction is essential for making effective remedial decisions at many legacy mine sites. We combine a stream tracer injection and synoptic sampling study with data from shallow near-stream groundwater wells to...

Thousands of Lesser Scaup (Aythya affinis) die annually in the Upper Mississippi River System, USA, from intestinal infections after birds consume exotic faucet snails, Bithynia tentaculata, infected with introduced parasites, Cyathocotyle bushiensis and Sphaeridiotrema pseudoglobulus. To date, the low frequency (biannual) and magnitude of mortality events from intestinal infections likely prevents trematode mortalities from...

This research focusses on three satellite-derived bathymetry methods and optical satellite instruments: (1) a stereo photogrammetry bathymetry module (SaTSeaD) developed for the NASA Ames stereo pipeline open-source software (version 3.6.0) using stereo WorldView data; (2) physics-based radiative transfer equations (PBSDB) using Landsat data; and (3) a modified...

There has been a growing interest in integrating geological and ecological processes for sustainable river management and restoration. Lotic systems are shaped by diverse physical processes, including geology, geomorphology, hydrology, and interactions with terrestrial processes. However, restoration practices often prioritize specific habitats or river forms without fully considering the underlying...

The U.S. Great Lakes Areas of Concern (AOCs) have been designated due to significant environmental degradation, with multiple Beneficial Use Impairments (BUIs) requiring remediation before delisting. The “fish tumors or other deformities” BUI remains at the Sheboygan River and the Lower Green Bay and Fox River AOCs,...

The 29 July 2025 Mw 8.8 Kamchatka, Russia, earthquake was the sixth largest instrumentally recorded earthquake. This event was seismically well observed at regional and teleseismic distances, but publicly available near‐source data were sparse at the time of the event, presenting unique challenges for rapid source and impact characterization. The U.S....

With frequent wildfires, powerful rainstorms, steep terrain, and dense population, California is particularly vulnerable to postfire hazards like flooding and debris flow. Major postfire flooding and debris-flow events can be more costly than the fire itself, causing dozens of fatalities and widespread damage (Chawner, 1934; Lancaster et al., 2021). Smaller...

The National Park of American Samoa (NPSA), which protects some of the most intact tropical rainforest in the South Pacific, is exposed to recurring, intense tropical cyclones, including Tropical Cyclone Gita in 2018. In combination with other anthropogenic pressures, cyclones represent a potential source of disturbance to landbird populations, particularly...

We examined ‘ōpe‘ape‘a, or Hawaiian hoary bat (Lasiurus semotus; Chiroptera: Vespertilionidae), acoustic activity and surveyed potential roost trees at the Ford Island Chief Petty Officer’s (CPO) Bungalows Neighborhood of Pearl Harbor National Memorial (PERL) on the island of O‘ahu. We established four acoustic monitoring stations (PERL1–PERL4) that operated nightly to...

The management of acid mine drainage (AMD) impacted catchments, such as the Odiel River basin, in southwestern Spain, prioritizes reclamation to meet water resources needs. Assessing water composition across its watercourses is needed to identify major AMD contributors and potentially guide remediation efforts. An equilibrium-based mixing model...

The rate of earthquakes in a region is a fundamental input to Probabilistic Seismic Hazard Analysis. We present a Monte Carlo method for computing that rate from seismicity catalogs while including a range of data and analysis uncertainties. This method is applied to regions for which the b value is assumed to...

At many petroleum hydrocarbon spill sites, residual spilled product forms a long-term source of groundwater contamination. The phrase source zone natural depletion is used to refer to the mass loss rates. Overall mass lost under environmental conditions was analyzed using conservative biomarker concentrations for a 1979 oil spill in northern...

ObjectiveThe Santa Ana Sucker Pantosteus santaanae is endemic to southern California and is listed as threatened under the U.S. Endangered Species Act. Seasonal limitations on conventional sampling and inconsistencies in survey methodologies have led to an incomplete understanding of population dynamics. Alternative sampling methods have the potential to...

Agricultural conservation practices are often used to protect stream health while continuing food production. However, recovery of stream health is often not as rapid or extensive as planned. The efficacy of practices may be improved by promoting their continued use by landowners (i.e., persistence) after cost-share contracts...

Remote sensing can provide reliable information on river depths and this approach might be particularly valuable in areas that are difficult to survey via conventional field methods. In this study, we assessed the potential to map the bathymetry of an inaccessible proglacial river in Alaska from both aerial orthophotos and...

Solar energy development is increasing in warm deserts of the southwestern United States, and ecovoltaics has emerged as an approach to maintain ecosystem function within solar facilities while meeting increasing regional energy demands. The Solar Gemini Project, located in the northeastern Mojave Desert, USA, is one of largest photovoltaic facilities...

Wildfires can have complex effects on aquatic communities, which can be either beneficial or adverse depending on the setting. In California, USA, the size, frequency, and severity of wildfires has greatly increased over the last few decades. Understanding the effects of fire on aquatic ecosystem health and human land use...

Chronic wasting disease (CWD) is a widespread and incurable cervid disease. Despite continuing investments, the logistical challenges of CWD have required wildlife managers and researchers to navigate changing priorities with conflicting public perceptions. When overcoming difficult management problems, leveraging exploratory methods may identify previously unrecognized hypotheses. In this study, we...

Increasing levels of chloride in surface water are associated with detrimental effects on water quality, aquatic ecosystems, infrastructure, and human health. Numerous mass-balance studies have inferred watershed transport processes by interpreting chloride inputs and outputs, but few represent internal dynamics explicitly. We constructed a coupled water/chloride mass balance model to...

Floating photovoltaics (floating solar panels; FPV) can reduce the negative impacts of solar energy development in terrestrial environments, but their effects on freshwater ecosystems remain poorly understood. We examined potential FPV interactions with avian biodiversity, using previously modeled technical potential of FPV in the northeastern United States. We developed a...

Many salamander populations are declining, and methods to determine how best to allocate limited resources to slow or reverse these declines could support land managers in their decision‐making processes. Multiple types of uncertainty may delay management decisions, including when (1) knowledge of a species' ecology is incomplete,...

San Francisco Bay, California, typically has chlorophyll a (chl-a) concentrations below 10 µg L−1, despite nutrient loadings exceeding those in many estuaries with recurring harmful algal blooms (HABs). However, in August 2022 there was a Heterosigma akashiwo (raphidophyte) bloom with chl-a concentrations exceeding 450 µg L−1, resulting in widespread hypoxia and fish die-off. We used protist community...