Southern sea otter (Enhydra lutris nereis) population biology at Big Sur and Monterey, California --Investigating the consequences of resource abundance and anthropogenic stressors for sea otter recovery
M. Tim Tinker, Joseph A. Tomoleoni, Benjamin P. Weitzman, Michelle Staedler, Dave Jessup, Michael J. Murray, Melissa Miller, Tristan Burgess, Lizabeth Bowen, A. Keith Miles, Nicole Thometz, Lily Tarjan, Emily Golson, Francesca Batac, Erin Dodd, Eva Berberich, Jessica Kunz, Gena Bentall, Jessica Fujii, Teri Nicholson, Seth Newsome, Ann Melli, Nicole LaRoche, Holly MacCormick, Andy Johnson, Laird Henkel, Chris Kreuder-Johnson, Pat Conrad
2019, Open-File Report 2019-1022
The range of the southern sea otter (Enhydra lutris nereis) spans most of the central California coast from Half Moon Bay to Gaviota. Some coastal areas within this range are heavily developed and highly impacted by humans, while other areas are wild and largely pristine. Determining the relative importance of...
Snowmelt-triggered earthquake swarms at the margin of Long Valley Caldera, California
Emily K. Montgomery-Brown, David R. Shelly, Paul A. Hsieh
2019, Geophysical Research Letters (46) 3698-3705
Fluids are well known to influence earthquakes, yet rarely are earthquakes convincingly linked to precipitation. Weak modulation or limited data often leads to ambiguous interpretations. In contrast, here we find that shallow seismicity in the Sierra Nevada range near Long Valley Caldera is strongly modulated by snowmelt....
Stream metabolism increases with drainage area and peaks asynchronously across a stream network
Francine H. Mejia, Alexander K. Fremier, Joseph R. Benjamin, J. Ryan Bellmore, Adrianne Z. Grimm, Grace A. Watson, Michael Newsom
2019, Aquatic Sciences (81) 1-17
Quantifying the spatial and temporal dynamics of stream metabolism across stream networks is key to understanding carbon cycling and stream food web ecology. To better understand intra-annual temporal patterns of gross primary production (GPP) and ecosystem respiration (ER) and their variability across space, we continuously measured dissolved oxygen and modeled...
Evidence for non-steady-state carbon emissions from snow-scoured alpine tundra
John F. Knowles, Peter D. Blanken, Corey Lawrence, Mark W. Williams
2019, Nature Communications (10)
High-latitude warming is capable of accelerating permafrost degradation and the decomposition of previously frozen carbon. The existence of an analogous high-altitude feedback, however, has yet to be directly evaluated. We address this knowledge gap by coupling a radiocarbon-based model to 7 years (2008–2014) of continuous eddy covariance data from a...
A cautionary tale of topography and tilt from Kilauea Caldera
Jessica A. Johnson, Michael P. Poland, Kyle R. Anderson, Juliet Biggs
2019, Geophysical Research Letters (46) 4221-4229
We conduct finite element analysis to investigate the effect of sharp topography on surface ground deformation caused by pressure changes in a magma reservoir. Tilt data express the horizontal gradient of vertical displacement and therefore can emphasize small variations in deformation that go unnoticed using other methods. We find that...
Cryptosporidium incidence and surface water influence of groundwater supplying public water systems in Minnesota, USA
Joel P. Stokdyk, Susan K. Spencer, James F. Walsh, Jane R. de Lambert, Aaron D. Fimstahl, Anita C. Anderson, Lih-in W. Rezania, Mark A. Borchardt
2019, Environmental Science & Technology (23) 3391-3398
Regulations for public water systems (PWS) in the U.S. consider Cryptosporidium a microbial contaminant of surface water supplies. Ground- water is assumed free of Cryptosporidium unless surface water is entering supply wells. We determined the incidence of Cryptosporidium in PWS wells varying in surface water influence. Community and noncommunity PWS...
Comparison of methods to examine diet of feral horses from non-invasively collected fecal samples
Sarah R.B. King, Kathryn A. Schoenecker
2019, Rangeland Ecology and Management (72) 661-666
Feral horses (Equus ferus caballus) have become abundant on public lands in the American West, particularly over the past 10 yr. In areas where they are overabundant, there is risk of habitat degradation. Most previous studies on diet and habitat use of feral horses were conducted more than 20 yr ago; rangelands have changed considerably in...
Potential spread of cheatgrass (Bromus tectorum) by feral horses (Equus ferus caballus) in Western Colorado
Sarah R.B. King, Kathryn A. Schoenecker, Daniel J. Manier
2019, Rangeland Ecology and Management (72) 706-710
The invasive grass cheatgrass (Bromus tectorum L.) presents major challenges for land management and habitat conservation in the western United States. Feral horses (Equus ferus caballus) have become overabundant in some areas of the West and can impact fragile semiarid ecosystems. Amid ongoing efforts to control cheatgrass in the Great Basin, we conducted a study...
Relative abundance and molecular evolution of Lake Sinai Virus (Sinaivirus) clades
Robert S. Cornman
2019, PeerJ (7)
Lake Sinai Viruses (Sinaivirus) are commonly detected in honey bees (Apis mellifera) but no disease phenotypes or fitness consequences have yet been demonstrated. This viral group is genetically diverse, lacks obvious geographic structure, and multiple lineages can co-infect individual bees. While phylogenetic analyses have been performed, the molecular evolution...
A supervolcano and its sidekicks: A 100 ka eruptive chronology of the Fish Canyon Tuff and associated units of the La Garita magmatic system
Leah E. Morgan, Samuel Johnstone, Amy K. Gilmer, Michael A. Cosca, Ren A. Thompson
2019, Geology (47) 453-456
Establishing temporal constrains on major volcanic eruptions is limited by the precision of existing geochronometers. Prior work on the La Garita caldera, created by the eruption of the Fish Canyon Tuff, failed to resolve temporal differences between pre-, syn-, and post-collapse eruptive units. Here, we report 40Ar/39Ar geochronologic data supporting...
Validating the performance of occupancy models for estimating habitat use and predicting the distribution of highly-mobile species: A case study using the American black bear
Matthew J. Gould, William R. Gould, James W. Cain III, Gary W. Roemer
2019, Biological Conservation (234) 28-36
Occupancy models have become a valuable tool for estimating wildlife-habitat relationships and for predicting species distributions. Highly-mobile species often violate the assumption that sampling units are geographically closed shifting the probability of occupancy to be interpreted as the probability of use. We used occupancy models, in conjunction with noninvasive sampling,...
Hydraulic conductivity estimates from slug tests in the Big Sioux aquifer near Sioux Falls, South Dakota
William G. Eldridge, Colton J. Medler
2019, Scientific Investigations Report 2019-5013
Hydraulic conductivity estimates were made for 15 observation wells using slug-out (rising-head) tests in the Big Sioux aquifer near Sioux Falls, South Dakota, as part of a cooperative study with the City of Sioux Falls to characterize the hydrogeology and the extent of the Big Sioux aquifer north of the...
Extreme reduction in nutritional value of a key forage fish during the Pacific marine heatwave of 2014–2016
Vanessa R. von Biela, Mayumi L. Arimitsu, John F. Piatt, Brielle Heflin, Sarah K. Schoen, Jannelle Trowbridge, Chelsea Clawson
2019, Marine Ecology Progress Series (613) 171-182
Pacific sand lance Ammodytes personatus are a key forage fish in the North Pacific for many species of salmon, groundfish, seabirds, and marine mammals and have historically been important to predators in relatively warm years. However, extreme declines in the nutritional value of sand lance in Prince William Sound, Alaska, USA,...
Quantitative coseismic and precipitation-induced landslide risk mapping for the country of Lebanon
William Pollock, Joseph Wartman, Grace Abou-Jaoude, Alex R. Grant
2019, Conference Paper, Geo-Congress 2019
Quantitative landslide risk assessment is a key step in creating appropriate land use policies. The forced migration of those displaced by recent events in Syria has highlighted the need for studies to guide humanitarian aid and resettlement policies. In 2011, armed...
Relatedness within and among Myotis septentrionalis colonies at a local scale
W. Mark Ford, Miluska Olivera-Hyde, Alexander Silvis, Eric M. Hallerman, Eric R. Britzke
2019, Canadian Journal of Zoology
Abstract: We assessed parentage within and among maternity colonies of the northern long-eared bat (Myotis septentrionalis Troessart 1897) in north-central Kentucky from 2011–2013 to better understand colony social structure, formation, and membership dynamics. We intensively sampled colonies in close and remote (> 10 km) spatial proximity both before and...
Downstream‐propagating channel responses to decadal‐scale climate variability in a glaciated river basin
Scott W. Anderson, Christopher P. Konrad
2019, Journal of Geophysical Research: Earth Surface (124) 902-919
Regional climate is an important control on the rate of coarse sediment mobilization and transport in alpine river systems. Changes in climate are then expected to cause a cascade of geomorphic responses, including adjustments in downstream channel morphology. However, the mechanics and sensitivity of channel response to short‐term climate variability...
Defining the limits of spectrally based bathymetric mapping on a large river
Carl J. Legleiter, Ryan L. Fosness
2019, Remote Sensing (11) 1-29
Remote sensing has emerged as a powerful method of characterizing river systems but is subject to several important limitations. This study focused on defining the limits of spectrally based mapping in a large river. We used multibeam echosounder (MBES) surveys and hyperspectral images from a deep, clear-flowing channel to develop...
Regression models for estimating sediment and nutrient concentrations and loads at the Kankakee River, Shelby, Indiana, December 2015 through May 2018
Timothy R. Lathrop, Aubrey R. Bunch, Myles S. Downhour
2019, Scientific Investigations Report 2019-5005
The Kankakee River in northern Indiana flows through the area once known as the Grand Marsh. Beginning in the 1860s, anthropogenic changes to the river within Indiana resulted in downstream flooding and additional transport of sediment and nutrients. In 2015, the U.S. Geological Survey, in cooperation with the Indiana Department...
State-space analysis of power to detect regional brook trout population trends over time
Kasey C. Pregler, R. Daniel Hanks, Evan S. Childress, Nathaniel P. Hitt, Daniel J. Hocking, Benjamin H. Letcher, Yoichiro Kanno
2019, Canadian Journal of Fisheries and Aquatic Sciences (76) 2145-2155
Threats to aquatic biodiversity are expressed at broad spatial scales, but identifying regional trends in abundance is challenging owing to variable sampling designs, and temporal and spatial variation in abundance. We compiled a regional dataset of brook trout Salvelinus fontinalis counts across their southern range representing 326 sites from eight...
Better approaches to managing drought in the American Southwest
Patrick Lambert, Timothy N. Titus, Andrea Ostroff
2019, Eos, Transactions, American Geophysical Union (100)
The second in a series of USGS Southwest Region (SWR) “Science Exchange” annual workshops, focused on USGS drought science. The participants considered how extreme drought conditions are evolving in much of the American southwest, with an emphasis on integrated drought science planning at the USGS bureau and program levels. The...
User’s manual for the Draper climate-distribution software suite with data‑evaluation tools
John M. Donovan, Kathryn M. Koczot
2019, Techniques and Methods 7-C22
Development of a time series of spatially distributed climate data is an important step in the process of developing physically based environmental models requiring distributed inputs of climate data beyond what is available from observations collected at climate stations. To prepare inputs required for model-mapping units across the study area,...
100-kyr paced climate change in the Pliocene warm period, Southwest Pacific
Rocio Caballero-Gill, Timothy D. Herbert, Harry Dowsett
2019, Paleoceanography and Paleoclimatology (34) 524-525
The mid to late Pliocene (~4.2-2.8 Ma.) represents an experiment in climate sensitivity to orbital pacing in which nearly all continental ice was confined to the Southern Hemisphere. Most studies have emphasized the dominant role of obliquity in determining changes in ice volume and temperature at this time, although most records come from the...
Environmental regulation of sex determination in fishes: Insights from Atheriniformes
Y. Yamamoto, R. S. Hattori, Reynaldo Patino, C. A. Strüssmann
2019, Book chapter
Sex determination is the first step toward the establishment of phenotypic sex in most vertebrates. Aquatic poikilotherms such as teleost fishes exhibit a high diversity of sex-determination mechanisms and gonadal phenotypes that are remarkably plastic and responsive to a variety of environmental factors (e.g., water temperature, pH, salinity, photoperiod, population density)....
Growth disparity in sympatric kokanee breeding groups
Zachary B. Klein, Michael C. Quist, Andrew M. Dux, Matthew P. Corsi
2019, North American Journal of Aquaculture (81) 169-177
Growth is arguably the most important dynamic rate function due to its interaction with survival and recruitment. As such, understanding the mechanisms underlying growth is a primary focus of fisheries research. Kokanee Oncorhynchus nerka in Lake Pend Oreille, Idaho, provide an interesting case study for investigating the factors that influence growth. Early‐run...
Estimating the energy expenditure of free‐ranging polar bears using tri‐axial accelerometers: A validation with doubly labeled water
Anthony M. Pagano, Terrie M. Williams
2019, Ecology and Evolution (9) 4210-4219
Measures of energy expenditure can be used to inform animal conservation and management, but methods for measuring the energy expenditure of free‐ranging animals have a variety of limitations. Advancements in biologging technologies have enabled the use of dynamic body acceleration derived from accelerometers as a proxy for energy expenditure. Although...
