Article
Environmental Sciences
Alice Peiying Wang, Jason Conder, Bart Chadwick, Gunther Rosen
Summary: This study demonstrates the effectiveness of activated carbon-based amendments in reducing the availability of sediment-associated organic compounds, such as polychlorinated biphenyls (PCBs). The long-term monitoring results show a significant reduction in PCB availability and no negative impacts on the benthic community. The study also explores the use of carbon petrography and black carbon chemical oxidation methods for quantifying activated carbon content.
ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY
(2022)
Article
Green & Sustainable Science & Technology
Jessica L. Copertino, Katherine Harris, Lyndsey Chute, Linda J. Walters
Summary: The restoration of oyster reefs in Mosquito Lagoon has successfully restored benthic invertebrate populations and bird communities to levels similar to natural reefs.
Article
Ecology
Daniel P. Malone, Kathryn Davis, Steve I. Lonhart, Avrey Parsons-Field, Jennifer E. Caselle, Mark H. Carr
Summary: Kelp forests are highly productive ecosystems that provide a wide range of ecosystem services. Recognizing their importance, the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO) conducted a large-scale, long-term monitoring study of kelp forest ecosystems along the coast of California and Oregon. By surveying the ecological community and geomorphological attributes annually, the study aimed to understand the spatial and temporal patterns of kelp forests and evaluate the contributions of biological and environmental variables. The data from this study have been used to inform fisheries management, design marine protected areas, and assess the ecological consequences of climate change.
Article
Ecology
David E. Rundio, Roberto Rivera, Peter S. Weiss-Penzias
Summary: Marine fog has been identified as a source of methylmercury (MeHg) in some terrestrial food webs in coastal California. Terrestrial invertebrates may have higher mercury concentrations than aquatic invertebrates, leading to higher mercury exposure in fish that consume terrestrial subsidies.
Article
Ecology
Veronica Padilla Vriesman, Sandra J. Carlson, Tessa M. Hill
Summary: This study analyzed the shells of California mussel and identified three mineralogical layers within the shell, with California mussel being the only Mytilus species to precipitate a secondary calcite layer. The research found that the light bands within the inner calcite layer are strongly correlated with winter collection months, indicating periods with moderate, stable temperatures and minimal upwelling. Additionally, the study showed that modern shells have thinner inner calcite layers and less well-defined growth bands compared to archival shells, suggesting a difference in calcification rate over the past 20 years.
Article
Ecology
Krysta H. Rogers, David Arranz-Solis, Jeroen P. J. Saeij, Stephany Lewis, Asli Mete
Summary: The study identified Cooper's hawks and red-tailed hawks in North America as potential definitive hosts of Sarcocystis calchasi, expanding the known host range of the parasite in the region.
INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE
(2022)
Article
Environmental Sciences
Joseph J. Kim, Kelsey Delisle, Tanya M. Brown, Peter S. Ross, Marie Noel
Summary: At-risk resident killer whale populations and their main prey, Chinook Salmon, in the northeastern Pacific, Canada, are exposed to various contaminants, including chemical elements from natural and anthropogenic sources, which may hinder their recovery. This study analyzed the concentrations of 36 chemical elements in subtidal surface sediments collected from 98 sites along the British Columbia coast. The findings showed that metals such as mercury, cadmium, arsenic, nickel, copper, and lead were present in higher concentrations in certain areas, indicating local sources of contamination. The assessment of marine habitat quality based on metal concentrations and guidelines revealed potential threats to both Chinook Salmon and resident killer whale populations.
ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Shannon Klotsko, Jillian Maloney, Janet Watt
Summary: In this study, new high-resolution chirp subbottom data is used to map and characterize the shallow expression of the Kirby Hills fault in the Sacramento-San Joaquin Delta. The results show a broad zone of deformation associated with the eastern strand of the fault, changing along the river channel. Radiocarbon dates provide minimum age constraints for the deformation. The study also highlights the difficulties of conducting paleoseismic studies in a fluvial environment.
Correction
Ecology
James J. Willacker, Collin A. Eagles-Smith, Vicki S. Blazer
Summary: A correction notice has been published for this paper, please refer to the link for details.
Article
Ecology
Allyson K. Jackson, Collin A. Eagles-Smith, W. Douglas Robinson
Summary: Cross-ecosystem subsidies play a crucial role in transferring nutrients between ecosystems. This study focuses on the reliance of riparian predators on aquatic prey sources and the correlation between aquatic prey sources and mercury concentrations in arachnids and songbirds. Results show that arachnid families and songbird species vary in their dependency on aquatic prey sources, with a positive correlation between the amount of aquatic prey in their diet and their mercury concentrations. The higher reliance on aquatic prey sources early in the season for songbirds may lead to elevated mercury exposure, potentially impacting their breeding and development.
ECOLOGY AND EVOLUTION
(2021)
Article
Chemistry, Multidisciplinary
Brett A. Poulin, Sarah E. Janssen, Tylor J. Rosera, David P. Krabbenhoft, Collin A. Eagles-Smith, Joshua T. Ackerman, A. Robin Stewart, Eunhee Kim, Zofia Baumann, Jeong-Hoon Kim, Alain Manceau
Summary: The study indicates that in waterbirds, a portion of methylmercury is demethylated to inorganic mercury, primarily in the form of mercury tetraselenolate. The isotopic ratios of mercury in tissues correlate linearly with the abundance of mercury tetraselenolate, suggesting a kinetic isotope effect during in vivo methylmercury demethylation. The findings demonstrate a selenium-dependent demethylation reaction in birds and provide new insights into the internal transformations and cycling of methylmercury and mercury tetraselenolate.
ACS EARTH AND SPACE CHEMISTRY
(2021)
Article
Geochemistry & Geophysics
Barbara Kleine, Andri Stefansson, Robert A. Zierenberg, Heejin Jeon, Martin J. Whitehouse, Kristjan Jonasson, Gudmundur O. Fridleifsson, Tobias B. Weisenberger
Summary: The study of natural anhydrite and pyrite from Mid-Atlantic ridge near Iceland reveals that key variables controlling anhydrite formation and sulfate recycling in the oceanic crust are influenced by the isotope composition of the source fluid, extent of water-rock interaction, temperature, and redox conditions. Hydrothermal anhydrite and pyrite exhibit specific delta S-34 and delta O-18 values, which indicate the processes of anhydrite formation and sulfur recycling in the oceanic crust.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geosciences, Multidisciplinary
Nestor Ramirez-Zerpa, Ronald M. Spelz, Ismael Yarbuh, Raquel Negrete-Aranda, Juan Contreras, David A. Clague, Florian Neumann, David W. Caress, Robert Zierenberg, Antonio Gonzalez-Fernandez
Summary: The study established the architecture of the Pescadero Basin Complex by utilizing multibeam bathymetric data and interpretation of seismic reflection profiles. It was found that fundamental elements controlling basin architecture and evolution are the geometry of the initial configuration of the master strike-slip fault step-over and fault dynamics.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2022)
Article
Engineering, Environmental
Ryan F. Lepak, Jacob M. Ogorek, Krista K. Bartz, Sarah E. Janssen, Michael T. Tate, Yin Runsheng, James P. Hurley, Daniel B. Young, Collin A. Eagles-Smith, David P. Krabbenhoft
Summary: This study assessed the importance of migrating oceanic salmon, volcanic activity, and atmospheric deposition to fish mercury burden by analyzing lake trout in 13 remote lakes in southwestern Alaska. The results showed that volcanic activity is a significant additional source of mercury in proximate lakes, while migratory salmon contribute little methylmercury directly to lake trout. The study also found niche partitioning and a complex suite of ecological interactions in lake trout populations.
ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS
(2022)
Article
Engineering, Environmental
Austin K. Baldwin, Collin A. Eagles-Smith, James J. Willacker, Brett A. Poulin, David P. Krabbenhoft, Jesse Naymik, Michael T. Tate, Dain Bates, Nick Gastelecutto, Charles Hoovestol, Chris Larsen, Alysa M. Yoder, James Chandler, Ralph Myers
Summary: Anoxic conditions within reservoirs lead to the production of methylmercury (MeHg), which plays a key role in the uptake of mercury in aquatic food webs. However, the timing, magnitude, and relative importance of MeHg uptake and export in water versus biological compartments within reservoirs remain poorly understood. This study examined the relationships between reservoir stratification, anoxia, and MeHg concentrations and export loads in aqueous and biological compartments in two reservoirs of the Hells Canyon Complex. The results suggest that destratification of the reservoirs leads to an increase in MeHg concentrations in filter-passing water, zooplankton, suspended particles, and detritus. The export of MeHg appears to be strongly influenced by reservoir anoxia, and only a small percentage of MeHg is exported through biological compartments.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Geosciences, Multidisciplinary
David A. Clague, Robert A. Zierenberg, Jennifer B. Paduan, David W. Caress, Brian L. Cousens, Brian M. Dreyer, Alice S. Davis, James McClain, Stephanie L. Ross
Summary: The Escanaba segment has thick sediment deposits with complex surface deformation and debris avalanche landslides. The uplifted hills are associated with hydrothermal chimneys, pockmarks, and deposits of oil and sulfide on the seafloor.
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
(2022)
Article
Engineering, Environmental
Freya E. Rowland, Erin Muths, Collin A. Eagles-Smith, Craig A. Stricker, Johanna M. Kraus, Rachel A. Harrington, David M. Walters
Summary: Measuring total mercury (THg), methylmercury (MeHg), and isotopic compositions (delta C- 13, delta N-15) in boreal chorus frogs (Pseudacris maculata) across five life stages, significant differences were found in concentrations and percent MeHg among the stages. Frog MeHg concentrations peaked during metamorphosis and hibernation, which are energetically demanding stages. The endogenous processes of metamorphosis and hibernation resulted in MeHg bioamplification, decoupling it from dietary and trophic position indicators.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Environmental Sciences
Garth Herring, Collin A. Eagles-Smith, Jeremy A. Buck
Summary: Anticoagulant rodenticides (AR) have been widely used for rodent control globally for decades, but they have also caused poisoning in wildlife. This study evaluated AR exposure and physiological responses in common ravens and turkey vultures in Oregon between 2013 and 2019. The results showed widespread AR exposure in these avian scavengers, with potential implications for the newly established California condor population in northern California.
ENVIRONMENTAL POLLUTION
(2023)
Article
Environmental Sciences
Vicki S. Blazer, Heather L. Walsh, Adam J. Sperry, Brenna Raines, James J. Willacker, Collin A. Eagles-Smith
Summary: Total mercury (THg) levels in smallmouth bass were correlated with visible abnormalities, macrophage aggregates, and tissue parasite burdens. In males, THg was positively associated with plasma vitellogenin, estrogen receptor 81, and androgen receptor alpha, while there was a negative association with estrogen receptors alpha and 82 and androgen receptors 8. In females, THg showed a negative correlation with plasma vitellogenin, vitellogenin, choriogenin, estrogen receptor 82, and 178 hydroxysteroid dehydrogenase. These associations suggest that mercury may be an important environmental stressor contributing to adverse effects in smallmouth bass populations.
ENVIRONMENTAL POLLUTION
(2023)
Article
Environmental Sciences
Krista K. Bartz, Michael P. Hannam, Tammy L. Wilson, Ryan F. Lepak, Jacob M. Ogorek, Daniel B. Young, Collin A. Eagles -Smith, David P. Krabbenhoft
Summary: Mercury is a harmful pollutant in its organic form that poses risks to fish, wildlife, and humans. This study assessed mercury concentrations in lake trout collected from 14 lakes in southwest Alaska and identified factors associated with the variation in fish mercury concentrations. The results showed that mercury concentrations in water were consistently low, while mercury concentrations in lake trout varied greatly and were influenced by fish age and body condition.
ENVIRONMENTAL POLLUTION
(2023)
Article
Engineering, Environmental
Brian J. Tornabene, Blake R. Hossack, Brian J. Halstead, Collin A. Eagles-Smith, Michael J. Adams, Adam R. Backlin, Adrianne B. Brand, Colleen S. Emery, Robert N. Fisher, Jill Fleming, Brad M. Glorioso, Daniel A. Grear, Evan H. Campbell Grant, Patrick M. Kleeman, David A. W. Miller, Erin Muths, Christopher A. Pearl, Jennifer C. Rowe, Caitlin T. Rumrill, J. Hardin Waddle, Megan E. Winzeler, Kelly L. Smalling
Summary: This study conducted a sampling survey on 26 amphibian populations across multiple states in the United States and found that methylmercury contamination is widespread, with significant variation in concentrations among different sites. The accumulation of methylmercury in amphibians is strongly associated with life history traits such as size, sex, and species type. The study also revealed that the concentration of total mercury in dragonflies can serve as a reliable indicator of methylmercury bioaccumulation in amphibians, while the concentration in sediment is not a good predictor.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Environmental
Sarah E. Janssen, Christopher J. Kotalik, Collin A. Eagles-Smith, Gale B. Beaubien, Joel C. Hoffman, Greg Peterson, Marc A. Mills, David M. Walters
Summary: The transfer of aquatic contaminants, specifically mercury, to terrestrial animals through shoreline spiders has been studied, but there are still uncertainties regarding the estimation of mercury sources. This study collected spiders and aquatic insect larvae from different habitats to examine the transfer of mercury. The results showed a connection between benthic mercury sources and the aquatic food web, and highlighted the importance of selecting appropriate spider taxa for mercury monitoring efforts.
ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS
(2023)
Article
Engineering, Environmental
James J. Willacker, Collin A. Eagles-Smith, James A. Chandler, Jesse Naymik, Ralph Myers, David P. Krabbenhoft
Summary: Impoundment is a common hydrologic alteration that affects aquatic ecosystems, including mercury (Hg) cycling. Our study found that reservoirs and tailraces in the Snake River had higher total Hg concentrations in Smallmouth Bass compared to free-flowing segments. The presence of inconsistent stratification patterns in reservoirs and tailraces also resulted in higher Hg concentrations and increased fish and human health risk.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)