Insights into controls on hexavalent chromium in groundwater provided by environmental tracers, Sacramento Valley, California, USA
Andrew H. Manning, Christopher T. Mills, Jean M. Morrison, Lyndsay B. Ball
2015, Applied Geochemistry (62) 186-199
Environmental tracers are useful for determining groundwater age and recharge source, yet their application in studies of geogenic Cr(VI) in groundwater has been limited. Environmental tracer data from 166 wells located in the Sacramento Valley, northern California, were interpreted and compared to Cr concentrations to...
Detecting sea-level hazards: Simple regression-based methods for calculating the acceleration of sea level
Kara S. Doran, Peter A. Howd, Sallenger Jr.
2015, Open-File Report 2015-1187
This report documents the development of statistical tools used to quantify the hazard presented by the response of sea-level elevation to natural or anthropogenic changes in climate and ocean circulation. A hazard is a physical process (or processes) that, when combined with vulnerability (or susceptibility to the hazard), results in...
Statistical summaries of selected Iowa streamflow data through September 2013
David A. Eash, Padraic S. O'Shea, Jared R. Weber, Kevin T. Nguyen, Nicholas L. Montgomery, Adrian J. Simonson
2015, Open-File Report 2015-1214
Statistical summaries of streamflow data collected at 184 streamgages in Iowa are presented in this report. All streamgages included for analysis have at least 10 years of continuous record collected before or through September 2013. This report is an update to two previously published reports that presented statistical summaries of...
Smartphones reveal angler behavior: A case study of a popular mobile fishing application in Alberta, Canada
Jason T. Papenfuss, Nicholas Phelps, David C. Fulton, Paul A. Venturelli
2015, Fisheries (40) 318-327
Successfully managing fisheries and controlling the spread of invasive species depends on the ability to describe and predict angler behavior. However, finite resources restrict conventional survey approaches and tend to produce retrospective data that are limited in time or space and rely on intentions or attitudes rather than actual behavior....
Distributional changes in the western Burrowing Owl (Athene cunicularia hypugaea) in North America from 1967 to 2008
Alberto Macias-Duarte, Courtney J. Conway
2015, Journal of Raptor Research (49) 75-83
The quantification of shifts in bird distributions in response to climate change provides an opportunity to gain a deeper understanding of the processes that influence species persistence. We used data from the North American Breeding Bird Survey (BBS) to document changes in the distributional limits of the western Burrowing Owl...
An evaluation of the relations between flow regime components, stream characteristics, species traits and meta-demographic rates of warmwater stream fishes: Implications for aquatic resource management
James T. Peterson, C.P. Shea
2015, River Research and Applications (31) 1227-1241
Fishery biologists are increasingly recognizing the importance of considering the dynamic nature of streams when developing streamflow policies. Such approaches require information on how flow regimes influence the physical environment and how those factors, in turn, affect species-specific demographic rates. A more cost-effective alternative could be the use of dynamic...
Guidelines for evaluating performance of oyster habitat restoration
Lesley P. Baggett, Sean P. Powers, Robert D. Brumbaugh, Loren D. Coen, Bryan M. DeAngelis, Jennifer K. Greene, Boze T. Hancock, Summer M. Morlock, Brian L. Allen, Denise L. Breitburg, David Bushek, Jonathan H. Grabowski, Raymond E. Grizzle, Edwin D. Grosholz, Megan K. LaPeyre, Mark W. Luckenbach, Kay A. McGraw, Michael F. Piehler, Stephanie R. Westby, Philine S. E. zu Ermgassen
2015, Restoration Ecology (23) 737-745
Restoration of degraded ecosystems is an important societal goal, yet inadequate monitoring and the absence of clear performance metrics are common criticisms of many habitat restoration projects. Funding limitations can prevent adequate monitoring, but we suggest that the lack of accepted metrics to address the diversity of restoration objectives also...
Evidence from data storage tags for the presence of lunar and semilunar behavioral cycles in spawning Atlantic cod
Timothy B. Grabowski, Bruce J. McAdam, Vilhjalmur Thorsteinsson, Gudrun Marteinsdottir
2015, Environmental Biology of Fishes (98) 1767-1776
Understanding the environmental processes determining the timing and success of reproduction is of critical importance to developing effective management strategies of marine fishes. Unfortunately it has proven difficult to comprehensively study the reproductive behavior of broadcast-spawning fishes. The use of electronic data storage tags (DSTs) has the potential to provide...
Factors affecting defensive strike behavior in Brown Treesnakes (Boiga irregularis) provoked by humans
McKayka M. Spencer, Bjorn Lardner, M.J. Mazurek, Robert N. Reed
2015, Herpetological Conservation and Biology (10) 703-710
Striking is a typical antipredator defense exhibited by many species of snakes. While trapping Brown Treesnakes (Boiga irregularis) on Guam, we observed that snakes most frequently struck at an approaching person at a site where snakes had been trapped, marked, and handled in the past. Using a combination of between-sites...
Interactive access to LP DAAC satellite data archives through a combination of open-source and custom middleware web services
Brian N. Davis, Jason Werpy, Aaron M. Friesz, Kevin Impecoven, Robert Quenzer, Tom Maiersperger, David J. Meyer
2015, IEEE Geoscience and Remote Sensing Letters (3) 8-20
Current methods of searching for and retrieving data from satellite land remote sensing archives do not allow for interactive information extraction. Instead, Earth science data users are required to download files over low-bandwidth networks to local workstations and process data before science questions can be addressed. New methods of extracting...
GOES-derived fog and low cloud indices for coastal north and central California ecological analyses
Alicia A. Torregrosa, Cindy Combs, Jeff Peters
2015, Earth and Space Science (3) 46-67
Fog and low cloud cover (FLCC) changes the water, energy, and nutrient flux of coastal ecosystems. Easy-to-use FLCC data are needed to quantify the impacts of FLC on ecosystem dynamics during hot, dry Mediterranean climate summers. FLCC indices were generated from 26,000 hourly night and day FLCC maps derived from...
Influence of ecological factors on prevalence of meningeal worm (Parelaphostrongylus tenuis infection in South Dakota, USA
Christopher N. Jacques, Jonathan A. Jenks, Troy W. Grovenburg, Robert W. Klaver, Shelli A. Dubay
2015, Journal of Wildlife Diseases (51) 332-340
The meningeal worm (Parelaphostrongylus tenuis) is a nematode parasite that commonly infects white-tailed deer (Odocoileus virginianus; WTD) throughout the deciduous forest biome and deciduous-coniferous ecotone of eastern and central North America; the species is not known to occur west of the grassland biome of central North America. We used county-specific...
A guide to Bayesian model selection for ecologists
Mevin Hooten, N.T. Hobbs
2015, Ecological Monographs (85) 3-28
The steady upward trend in the use of model selection and Bayesian methods in ecological research has made it clear that both approaches to inference are important for modern analysis of models and data. However, in teaching Bayesian methods and in working with our research colleagues, we have noticed a...
On the existence of maximum likelihood estimates for presence-only data
Trevor J. Hefley, Mevin Hooten
2015, Methods in Ecology and Evolution (6) 648-655
Presence-only data can be used to determine resource selection and estimate a species’ distribution. Maximum likelihood is a common parameter estimation method used for species distribution models. Maximum likelihood estimates, however, do not always exist for a commonly used species distribution model – the Poisson point process. We...
A 2-D process-based model for suspended sediment dynamics: A first step towards ecological modeling
F. M. Achete, M. van der Wegen, D. Roelvink, B. Jaffe
2015, Hydrology and Earth System Sciences (19) 2837-2857
In estuaries suspended sediment concentration (SSC) is one of the most important contributors to turbidity, which influences habitat conditions and ecological functions of the system. Sediment dynamics differs depending on sediment supply and hydrodynamic forcing conditions that vary over space and over time. A robust sediment transport model is a...
Cr(VI) occurrence and geochemistry in water from public-supply wells in California
John A. Izbicki, Michael Wright, Whitney A. Seymour, R. Blaine McCleskey, Miranda S. Fram, Kenneth Belitz, Bradley K. Esser
2015, Applied Geochemistry (63) 203-217
Hexavalent chromium, Cr(VI), in 918 wells sampled throughout California between 2004 and 2012 by the Groundwater Ambient Monitoring and Assessment-Priority Basin Project (GAMA-PBP) ranged from less than the study reporting limit of 1 microgram per liter (μg/L) to 32 μg/L. Statewide, Cr(VI) was reported in 31 percent of wells and equaled...
New insight into California’s drought through open data
Emily K. Read, Mary Bucknell, Megan Hines, James M. Kreft, Jessica M. Lucido, Jordan S. Read, Carl Schroedl, David M. Sibley, Shirley Stephan, Ivan Suftin, Phethala Thongsavanh, Jamon Van Den Hoek, Jordan I. Walker, Martin R Wernimont, Luke A. Winslow, Andrew N. Yan
2015, BayGEO Journal (8)
Historically unprecedented drought in California has brought water issues to the forefront of the nation’s attention. Crucial investigations that concern water policy, management, and research, in turn, require extensive information about the quality and quantity of California’s water. Unfortunately, key sources of pertinent data are unevenly distributed and frequently hard...
Evaluating multi-level models to test occupancy state responses of Plethodontid salamanders
Andrew J. Kroll, Tiffany S. Garcia, Jay E. Jones, Katie M. Dugger, Blake Murden, Josh Johnson, Summer Peerman, Ben Brintz, Michael Rochelle
2015, PLoS ONE (10)
Plethodontid salamanders are diverse and widely distributed taxa and play critical roles in ecosystem processes. Due to salamander use of structurally complex habitats, and because only a portion of a population is available for sampling, evaluation of sampling designs and estimators is critical to provide strong inference about Plethodontid ecology...
Rapid damage mapping for the 2015 M7.8 Gorkha earthquake using synthetic aperture radar data from COSMO-SkyMed and ALOS-2 satellites
Sang-Ho Yun, Kenneth W. Hudnut, Susan Owen, Frank Webb, Mark Simons, Patrizia Sacco, Eric Gurrola, Gerald Manipon, Cunren Liang, Eric Fielding, Pietro Milillo, Hook Hua, Alessandro Coletta
2015, Seismological Research Letters (86) 1549-1557
The 25 April 2015 Mw 7.8 Gorkha earthquake caused more than 8000 fatalities and widespread building damage in central Nepal. The Italian Space Agency’s COSMO–SkyMed Synthetic Aperture Radar (SAR) satellite acquired data over Kathmandu area four days after the earthquake and the Japan Aerospace Exploration Agency’s Advanced Land Observing Satellite-2 SAR satellite...
Breeding habitat associations and predicted distribution of an obligate tundra-breeding bird, Smith's Longspur
Teri C. Wild, Steven J. Kendall, Nikki Guldager, Abby N. Powell
2015, The Condor (117) 3-17
Smith's Longspur (Calcarius pictus) is a species of conservation concern which breeds in Arctic habitats that are expected to be especially vulnerable to climate change. We used bird presence and habitat data from point-transect surveys conducted at 12 sites across the Brooks Range, Alaska, 2003–2009, to identify breeding areas, describe...
Developing in situ non-destructive estimates of crop biomass to address issues of scale in remote sensing
Michael T. Marshall, Prasad S. Thenkabail
2015, Remote Sensing (7) 808-835
Ground-based estimates of aboveground wet (fresh) biomass (AWB) are an important input for crop growth models. In this study, we developed empirical equations of AWB for rice, maize, cotton, and alfalfa, by combining several in situ non-spectral and spectral predictors. The non-spectral predictors included: crop height (H), fraction of absorbed...
In-situ arsenic removal during groundwater recharge through unsaturated alluvium
David O’Leary, John A. Izbicki, T.J. Kim, Clark Ajawani, Donald Suarez, Thomas Barnes, Thomas Kulp, Matthew K. Burgess, Iwen Tseng
2015, Report
OBJECTIVES The purpose of this study was to determine the feasibility and sustainability of in-situ removal of arsenic from water infiltrated through unsaturated alluvium. BACKGROUND Arsenic is naturally present in aquifers throughout the southwestern United States and elsewhere. In January 2006, the U.S. Environmental Protection Agency (EPA) lowered the Maximum...
Using spatiotemporal statistical models to estimate animal abundance and infer ecological dynamics from survey counts
Paul B. Conn, Devin S. Johnson, Jay M. Ver Hoef, Mevin Hooten, Joshua M. London, Peter L. Boveng
2015, Ecological Monographs (85) 235-252
Ecologists often fit models to survey data to estimate and explain variation in animal abundance. Such models typically require that animal density remains constant across the landscape where sampling is being conducted, a potentially problematic assumption for animals inhabiting dynamic landscapes or otherwise exhibiting considerable spatiotemporal variation in density. We...
Towards forecasting the retreat of California’s coastal cliffs during the 21st century
Patrick W. Limber, Patrick L. Barnard, Cheryl Hapke
2015, Conference Paper, The proceedings of the coastal sediments 2015
In California, sea-level rise during the 21st century threatens to accelerate coastal cliff recession rates. To forecast such changes for managers and policymakers, models must play a key role. In this paper, we extend a ~70-year long dataset of measured historic sea cliff retreat rates in Southern California into the 21st century...
Adapting the U.S. National Hydrography Dataset to linked open data
Dalia E. Varanka, E. Lynn Usery, David M. Mattli
2015, Conference Paper, Cartography -- maps connecting the world: 27th International Cartographic Conference 2015 - ICC2015
A controlled vocabulary for the National Hydrography Dataset (NHD) of the United States was developed as Linked Open Data (LOD). The vocabulary has two main parts: a glossary and a set of triples reflecting the NHD data model as it is organized in geographic information systems (GIS). The glossary consists...
