Reverse weathering in marine sediments and the geochemical cycle of potassium in seawater: Insights from the K isotopic composition (41K/39K) of deep-sea pore-fluids
Danielle P. Santiago Ramos, Leah E. Morgan, Nicholas S. Lloyd, John A. Higgins
2018, Geochimica et Cosmochimica Acta (236) 99-120
In situ Al-silicate formation, also known as “reverse weathering,” is an important sink of many of the major and minor cations in seawater (e.g. Mg, K, and Li). However, the importance of this sink in global geochemical cycles and isotopic budgets of these elements remains poorly constrained. Here, we report on the...
Evolution of the 2015 Cotopaxi eruption revealed by combined geochemical & seismic observations
Silvana Hidalgo, Jean Battaglia, Santiago Arellano, Daniel Sierra, Benjamin Bernard, Rene Parra, Peter J. Kelly, Florian Dinger, Charlotte Barrington, Pablo Samaniego
2018, Geochemistry, Geophysics, Geosystems (19) 2087-2108
Through integration of multiple data streams to monitor volcanic unrest scientists are able to make more robust eruption forecast and to obtain a more holistic interpretation of volcanic systems. We examined gas emission and gas geochemistry, seismic and petrologic data recorded during the 2015 unrest of Cotopaxi (Ecuador) in order...
A method to value nature-related webcam viewing: The value of virtual use with application to brown bear webcam viewing
John B. Loomis, Leslie Richardson, Christopher Huber, Jeffrey Skibins, Ryan Sharp
2018, Journal of Environmental Economics and Policy (7) 452-462
There are an estimated 16,000 nature related remote web cameras that provide users around the world with an opportunity to view wildlife. Because there is no monetary price to view the webcams, we utilise variations in the viewers’ opportunity cost of time to estimate consumer surplus. We apply this model...
Exposure to synthetic hydraulic fracturing waste influences the mucosal bacterial community structure of the brook trout (Salvelinus fontinalis) epidermis
Heather S. Galbraith, Deborah D. Iwanowicz, Daniel E. Spooner, Luke R. Iwanowicz, David Keller, Paula M. Zelanko, Cynthia R. Adams
2018, AIMS Microbiology (4) 413-427
Production of natural gas using unconventional technologies has risen as demand for alternative fuels has increased. Impacts on the environment from waste generated from these processes are largely unexplored. In particular, the outcomes of organismal exposure to hydraulic fracturing waste have not been rigorously evaluated. We evaluated the effects of...
A framework for identifying and characterising coral reef “oases” against a backdrop of degradation
James R. Guest, Peter J. Edmunds, Ruth D. Gates, Ilsa B. Kuffner, Andreas J Andersson, Brian B. Barnes, Iliana Chollett, Travis A. Courtney, Robin Elahi, Kevin Gross, Elizabeth A. Lenz, Satoshi Mitarai, Peter J. Mumby, Hannah R. Nelson, Britt A. Parker, Hollie M. Putnam, Caroline S. Rogers, Lauren Toth
2018, Journal of Applied Ecology (55) 2865-2875
Human activities have led to widespread ecological decline; however, the severity of degradation is spatially heterogeneous due to some locations resisting, escaping, or rebounding from disturbances.We developed a framework for identifying oases within coral reef regions using long‐term monitoring data. We calculated standardised estimates of coral cover (z‐scores) to...
Book review: A new view on the species abundance distribution Stochastic communities: A mathematical theory of biodiversity
Donald L. DeAngelis
2018, Trends in Ecology and Evolution (33) 572-574
The sampled relative abundances of species of a taxonomic group, whether birds, trees, or moths, in a natural community at a particular place vary in a way that suggests a consistent underlying pattern, referred to as the species abundance distribution (SAD). Preston [1] conjectured that the numbers of species, plotted...
Adaptation with climate uncertainty: An examination of agricultural land use in the United States
Jianhong E. Mu, Bruce A. McCarl, Benjamin M. Sleeter, John T. Abatzoglou, Hongliang Zhang
2018, Land Use Policy (77) 392-401
This paper examines adaptation responses to climate change through adjustment of agricultural land use. The climate drivers we examine are changes in long-term climate normals (e.g., 10-year moving averages) and changes in inter-annual climate variability. Using US county level data over 1982 to 2012 from Census of Agriculture, we find...
Characterizing the sponge grounds of Grays Canyon, Washington, USA
Abby N. Powell, M. Elizabeth Clarke, Erica Fruh, Jason Chaytor, Henry M. Reiswig, Curt E. Whitmire
2018, Deep Sea Research Part II: Topical Studies in Oceanography (150) 146-155
Deep-sea sponge grounds are relatively understudied ecosystems that may provide key habitats for a large number of fish and invertebrates including commercial species. Glass sponge grounds have been discovered from the tropics to polar regions but there are only a few places with high densities of dictyonine sponges. Dictyonine glass...
Estimating lag to peak between rainfall and peak streamflow with a mixed-effects model
Pamela J. Lombard, David Holtschlag
2018, Journal of the American Water Resources Association (JAWRA) (54) 949-961
We test the use of a mixed-effects model for estimating lag to peak for small basins in Maine (drainage areas from 0.8 to 78 km2). Lag to peak is defined as the time between the center of volume of the excess rainfall during a storm event and the resulting peak...
Suspended-sediment concentrations and loads in the lower Mississippi and Atchafalaya rivers decreased by half between 1980 and 2015
Scott Mize, Jennifer C. Murphy, Timothy H. Diehl, Dennis K. Demcheck
2018, Journal of Hydrology (564) 1-11
The Weighted Regressions on Time, Discharge, and Season (WRTDS) model was used to derive estimates of suspended-sediment concentration (SSC) and suspended-sediment load (SSL), their dependence on discharge, and their trends with confidence intervals, for one site each on the lowermost Mississippi...
Combined effects of temperature and salinity on the physiology of two geographically-distant eastern oyster populations
S. M. Casas, R. Filgueira, R. Lavaud, L. A. Comeau, Megan La Peyre, J. F. La Peyre
2018, Journal of Experimental Marine Biology and Ecology (506) 82-90
Understanding why a species occupies a certain geographic range and predicting how they will be affected by climate change require characterizing physiological traits in geographically-distant populations. The objective of this study was to perform a direct comparison of two eastern oyster (Crassostrea virginica) populations that occupy contrasting temperature and salinity...
Variation in home range size and patterns in adult female American crocodiles Crocodylus acutus
Kristen M. Hart, Jeffrey S. Beauchamp, Michael S. Cherkiss, Frank Mazzotti
2018, Endangered Species Research (36) 161-171
The American crocodile Crocodylus acutus is a threatened species that uses relatively deep, open-water habitats with low salinity. Adult female American crocodiles nest on sandy coastal beaches, islands or human-made berms, assist in the hatching process, and can travel long distances to nesting habitat. We satellite-tracked 15 adult female American crocodiles in...
Insular biogeographic origins and high phylogenetic distinctiveness for a recently depleted lizard fauna from Christmas Island, Australia
Paul M. Oliver, Mozes P. K. Blom, Harold G. Cogger, Robert N. Fisher, Jonathan Q. Richmond, John C. Z. Woinarski
2018, Biology Letters (14) 1-5
Striking faunal turnover across Asia and Australasia, most famously along the eastern edge of the Sunda Shelf or ‘Wallace's Line’, has been a focus of biogeographic research for over 150 years. Here, we investigate the origins of a highly threatened endemic lizard fauna (four species) on Christmas Island. Despite occurring...
Reductive dechlorination rates of 4,4′-DDE (1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethenyl]benzene) in sediments of the Palos Verdes Shelf, CA
Robert P. Eganhouse, Christopher R. Sherwood, James Pontolillo, Brian Edwards, Patrick J. Dickhudt
2018, Marine Chemistry (203) 10-21
Wastes from the world's largest manufacturer of DDT (1-chloro-4-[2,2,2-trichloro-1-(4-chlorophenyl)ethyl]benzene) were released into the Los Angeles County municipal sewer system from 1947 to 1971. Following primary treatment, the effluent was discharged through a submarine outfall system whereupon a portion of the DDT and associated degradation products were deposited in sediments of...
DDT and related compounds in pore water of shallow sediments on the Palos Verdes Shelf, California, USA
Robert P. Eganhouse, Erica L. DiFilippo, James Pontolillo, William H. Orem, Paul C. Hackley, Brian Edwards
2018, Marine Chemistry (203) 78-90
For nearly two and a half decades following World War II, production wastes from the world's largest manufacturer of technical DDT (1-chloro-4-[2,2,2-trichloro-1-(4-chlorophenyl)ethyl]benzene) were discharged into sewers of Los Angeles County. Following treatment, the wastes were released via a submarine outfall system to nearshore coastal waters where a portion accumulated in...
Integrating animal movement with habitat suitability for estimating dynamic migratory connectivity
Marielle L. van Toor, Bart Kranstauber, Scott H. Newman, Diann J. Prosser, John Y. Takekawa, Georgios Technitis, Robert Weibel, Martin Wikelski, Kamran Safi
2018, Landscape Ecology (33) 879-893
ContextHigh-resolution animal movement data are becoming increasingly available, yet having a multitude of empirical trajectories alone does not allow us to easily predict animal movement. To answer ecological and evolutionary questions at a population level, quantitative estimates of a species’ potential to link patches or populations are of...
Quantifying anthropogenic contributions to century-scale groundwater salinity changes, San Joaquin Valley, California, USA
Jeffrey A. Hansen, Bryant Jurgens, Miranda S. Fram
2018, Science of the Total Environment (642) 125-136
Total dissolved solids (TDS) concentrations in groundwater tapped for beneficial uses (drinking water, irrigation, freshwater industrial) have increased on average by about 100 mg/L over the last 100 years in the San Joaquin Valley, California (SJV). During this period land use in the SJV changed from natural vegetation and dryland...
Harnessing big data to rethink land heterogeneity in Earth system models
Nathaniel W. Chaney, Marjolein H. J. Van Huijgevoort, Elena Shevliakova, Sergey Malyshev, Paul C. D. Milly, Paul P. G. Gauthier, Benjamin N. Sulman
2018, Hydrology and Earth System Sciences (22) 3311-3330
The continual growth in the availability, detail, and wealth of environmental data provides an invaluable asset to improve the characterization of land heterogeneity in Earth system models – a persistent challenge in macroscale models. However, due to the nature of these data (volume and complexity) and computational constraints, these data...
Thresholds and hotspots for shrub restoration following a heterogeneous megafire
Matthew Germino, David Barnard, Bill Davidson, Robert Arkle, David S. Pilliod, Matthew Fisk, Cara Applestein
2018, Landscape Ecology (33) 1177-1194
ContextReestablishing foundational plant species through aerial seeding is an essential yet challenging step for restoring the vast semiarid landscapes impacted by plant invasions and wildfire-regime shifts. A key component of the challenge stems from landscape variability and its effects on plant recovery.ObjectivesWe assessed landscape correlates, thresholds,...
Exposure to human-associated chemical markers of fecal contamination and self-reported illness among swimmers at recreational beaches
Melanie D Napier, Charles Poole, Jill R Stewart, David J Weber, Susan T. Glassmeyer, Dana W. Kolpin, Edward Furlong, Alfred P Dufour, Timothy J. Wade
2018, Environmental Science & Technology (52) 7513-7523
Anthropogenic chemicals have been proposed as potential markers of human fecal contamination in recreational water. However, to date, there are no published studies describing their relationships with illness risks. Using a cohort of swimmers at seven U.S. beaches, we examined potential...
Rapid crop cover mapping for the conterminous United States
Devendra Dahal, Bruce K. Wylie, Daniel Howard
2018, Scientific Reports (8)
Timely crop cover maps with sufficient resolution are important components to various environmental planning and research applications. Through the modification and use of a previously developed crop classification model (CCM), which was originally developed to generate historical annual crop cover maps, we hypothesized that such crop cover maps could be...
Dryland photoautotrophic soil surface communities endangered by global change
Emilio Rodriguez-Caballero, Jayne Belnap, Burkhard Budel, Paul J. Crutzen, Meinrat O. Andreae, Ulrich Poschl, Bettina Weber
2018, Nature Geoscience (11) 185-189
Photoautotrophic surface communities forming biological soil crusts (biocrusts) are crucial for soil stability as well as water, nutrient and trace gas cycling at regional and global scales. Quantitative information on their global coverage and the environmental factors driving their distribution patterns, however, are not readily available. We use observations and...
Seagrass impact on sediment exchange between tidal flats and salt Marsh, and the sediment budget of shallow bays
Carmine Donatelli, Neil Kamal Ganju, Sergio Fagherazzi, Nicoletta Leonardi
2018, Geophysical Research Letters (45) 4933-4943
Seagrasses are marine flowering plants that strongly impact their physical and biological surroundings and are therefore frequently referred to as ecological engineers. The effect of seagrasses on coastal bay resilience and sediment transport dynamics is understudied. Here we use six historical maps of seagrass distribution in Barnegat Bay, USA, to investigate...
A guide to processing bat acoustic data for the North American Bat Monitoring Program (NABat)
Brian Reichert, Cori Lausen, Susan Loeb, Ted Weller, Ryan Allen, Eric Britzke, Tara Hohoff, Jeremy Siemers, Braden Burkholder, Carl Herzog, Michelle Verant
2018, Open-File Report 2018-1068
The North American Bat Monitoring Program (NABat) aims to improve the state of conservation science for all species of bats shared by the United States, Canada, and Mexico. To accomplish this goal, NABat offers guidance and standardized protocols for acoustic monitoring of bats. In this document, “A Guide to Processing...
Diurnal patterns of methane flux from a seasonal wetland: mechanisms and methodology
Sheel Bansal, Brian Tangen, Raymond Finocchiaro
2018, Wetlands (45) 4933-4943
Methane emissions from wetlands are temporally dynamic. Few chamber-based studies have explored diurnal variation in methane flux with high temporal replication. Using an automated sampling system, we measured methane flux every 2.5 to 4 h for 205 diel cycles during three growing seasons (2013–2015) from a seasonal wetland in the Prairie...
