Sea otter health: challenging a pet hypothesis
Kevin D. Lafferty
2015, International Journal for Parasitology: Parasites and Wildlife (4) 291-294
A recent series of studies on tagged sea otters (Enhydra lutris nereis) challenges the hypothesis that sea otters are sentinels of a dirty ocean, in particular, that pet cats are the main source of exposure to Toxoplasma gondii in central California. Counter to expectations, sea otters from unpopulated stretches of...
Social living mitigates the costs of a chronic illness in a cooperative carnivore
Emily S. Almberg, Paul C. Cross, Andrew P. Dobson, Douglas W. Smith, Matthew C Metz, Daniel R. Stahler, Peter J. Hudson
2015, Ecology Letters (18) 660-667
Infection risk is assumed to increase with social group size, and thus be a cost of group living. We assess infection risk and costs with respect to group size using data from an epidemic of sarcoptic mange (Sarcoptes scabiei) among grey wolves (Canis lupus). We demonstrate that group size does...
Southern San Andreas Fault seismicity is consistent with the Gutenberg-Richter magnitude-frequency distribution
Morgan T. Page, Karen Felzer
2015, Bulletin of the Seismological Society of America (105) 2070-2080
The magnitudes of any collection of earthquakes nucleating in a region are generally observed to follow the Gutenberg-Richter (G-R) distribution. On some major faults, however, paleoseismic rates are higher than a G-R extrapolation from the modern rate of small earthquakes would predict. This, along with other observations, led to formulation...
MMI: Multimodel inference or models with management implications?
J. Fieberg, Douglas H. Johnson
2015, Journal of Wildlife Management (79) 708-718
We consider a variety of regression modeling strategies for analyzing observational data associated with typical wildlife studies, including all subsets and stepwise regression, a single full model, and Akaike's Information Criterion (AIC)-based multimodel inference. Although there are advantages and disadvantages to each approach, we suggest that there is no unique...
Genetic effects of habitat restoration in the Laurentian Great Lakes: an assessment of lake sturgeon origin and genetic diversity
Jamie Marie Marranca, Amy Welsh, Edward F. Roseman
2015, Restoration Ecology (23) 455-464
Lake sturgeon (Acipenser fulvescens) have experienced significant habitat loss, resulting in reduced population sizes. Three artificial reefs were built in the Huron-Erie corridor in the Great Lakes to replace lost spawning habitat. Genetic data were collected to determine the source and numbers of adult lake sturgeon spawning on the reefs...
Training conservation practitioners to be better decision makers
Fred A. Johnson, Mitchell J. Eaton, James H. Williams, Gitte H. Jensen, Jesper Madsen
2015, Sustainability (7) 8354-8373
Traditional conservation curricula and training typically emphasizes only one part of systematic decision making (i.e., the science), at the expense of preparing conservation practitioners with critical skills in values-setting, working with decision makers and stakeholders, and effective problem framing. In this article we describe how the application of decision science...
Slope activity in Gale crater, Mars
Colin M. Dundas, Alfred S. McEwen
2015, Icarus (254) 213-218
High-resolution repeat imaging of Aeolis Mons, the central mound in Gale crater, reveals active slope processes within tens of kilometers of the Curiosity rover. At one location near the base of northeastern Aeolis Mons, dozens of transient narrow lineae were observed, resembling features (Recurring Slope Lineae) that are potentially due...
Monitoring population status of sea otters (Enhydra lutris) in Glacier Bay National Park and Preserve, Alaska: options and considerations
George G. Esslinger, Daniel Esler, S. Howlin, L.A. Starcevich
2015, Open-File Report 2015-1119
After many decades of absence from southeast Alaska, sea otters (Enhydra lutris) are recolonizing parts of their former range, including Glacier Bay, Alaska. Sea otters are well known for structuring nearshore ecosystems and causing community-level changes such as increases in kelp abundance and changes in the size and number of...
Summer declines in activity and body temperature offer polar bears limited energy savings
J.P. Whiteman, H.J. Harlow, George M. Durner, R. Anderson-Sprecher, Shannon E. Albeke, Eric V. Regehr, Steven C. Amstrup, M. Ben-David
2015, Science (349) 295-298
Polar bears (Ursus maritimus) summer on the sea ice or, where it melts, on shore. Although the physiology of “ice” bears in summer is unknown, “shore” bears purportedly minimize energy losses by entering a hibernation-like state when deprived of food. Such a strategy could partially compensate for the loss of...
Age-specific vibrissae growth rates: a tool for determining the timing of ecologically important events in Steller sea lions
L.D. Rea, A.M. Christ, A.B. Hayden, V.K. Stegall, S.D. Farley, Craig A. Stricker, J.E. Mellish, John M. Maniscalco, J.N. Waite, V.N. Burkanov, K.W. Pitcher
2015, Marine Mammal Science (31) 1213-1233
Steller sea lions (SSL; Eumetopias jubatus) grow their vibrissae continually, providing a multiyear record suitable for ecological and physiological studies based on stable isotopes. An accurate age-specific vibrissae growth rate is essential for registering a chronology along the length of the record, and for interpreting the timing of ecologically important events....
Scale dependence of disease impacts on quaking aspen (Populus tremuloides) mortality in the southwestern United States
David M. Bell, John B. Bradford, William K. Lauenroth
2015, Ecology, Evolution, and Systematics (96) 1835-1845
Depending on how disease impacts tree exposure to risk, both the prevalence of disease and disease effects on survival may contribute to patterns of mortality risk across a species' range. Disease may accelerate tree species' declines in response to global change factors, such as drought, biotic interactions, such as...
Marine foraging ecology influences mercury bioaccumulation in deep-diving northern elephant seals
Sarah H. Peterson, Joshua T. Ackerman, Daniel P. Costa
2015, Proceedings of the Royal Society B: Biological Sciences (282)
Mercury contamination of oceans is prevalent worldwide and methylmercury concentrations in the mesopelagic zone (200–1000 m) are increasing more rapidly than in surface waters. Yet mercury bioaccumulation in mesopelagic predators has been understudied. Northern elephant seals (Mirounga angustirostris) biannually travel thousands of kilometres to forage within coastal and open-ocean regions...
Self-similar rupture implied by scaling properties of volcanic earthquakes occurring during the 2004-2008 eruption of Mount St. Helens, Washington
Rebecca M. Harrington, Grzegorz Kwiatek, Seth C. Moran
2015, Journal of Geophysical Research B: Solid Earth (120) 1966-1982
We analyze a group of 6073 low-frequency earthquakes recorded during a week-long temporary deployment of broadband seismometers at distances of less than 3 km from the crater at Mount St. Helens in September of 2006. We estimate the seismic moment (M0) and spectral corner frequency (f0) using a spectral ratio approach...
Climate-water quality relationships in Texas reservoirs
Rodica Gelca, Katharine Hayhoe, Ian Scott-Fleming, Caleb Crow, D. Dawson, Reynaldo Patino
2015, Hydrological Processes (30) 12-29
Water temperature, dissolved oxygen, and concentrations of salts in surface water bodies can be affected by the natural environment, local human activities such as surface and ground water withdrawals, land use, and energy extraction, and variability and long-term trends in atmospheric conditions including temperature and precipitation. Here, we quantify the...
A landsat data tiling and compositing approach optimized for change detection in the conterminous United States
Kurtis Nelson, Daniel R. Steinwand
2015, Photogrammetric Engineering and Remote Sensing (81) 573-586
Annual disturbance maps are produced by the LANDFIRE program across the conterminous United States (CONUS). Existing LANDFIRE disturbance data from 1999 to 2010 are available and current efforts will produce disturbance data through 2012. A tiling and compositing approach was developed to produce bi-annual images optimized for change detection. A...
Organic contaminant transport and fate in the subsurface: evolution of knowledge and understanding
Hedeff I. Essaid, Barbara A. Bekins, Isabelle M. Cozzarelli
2015, Water Resources Research (51) 4861-4902
Toxic organic contaminants may enter the subsurface as slightly soluble and volatile nonaqueous phase liquids (NAPLs) or as dissolved solutes resulting in contaminant plumes emanating from the source zone. A large body of research published in Water Resources Research has been devoted to characterizing and understanding processes controlling the transport and fate...
Reproductive traits of shovelnose sturgeon Scaphirhynchus platorynchus (Rafinesque, 1820) in the lower Platte River, Nebraska
M. J. Hamel, M.L. Rugg, M.A. Pegg, Reynaldo Patino, J.J. Hammen
2015, Journal of Applied Ichthyology (31) 592-602
We assessed reproductive status, fecundity, egg size, and spawning dynamics of shovelnose sturgeon Scaphirhynchus platorynchus in the lower Platte River. Shovelnose sturgeon were captured throughout each year during 2011 and 2012 using a multi-gear approach designed to collect a variety of fish of varying sizes and ages. Fish were collected monthly for...
Shear Wave Velocity and Site Amplification Factors for 25 Strong-Motion Instrument Stations Affected by the M5.8 Mineral, Virginia, Earthquake of August 23, 2011
Robert E. Kayen, Brad A. Carkin, Skye C. Corbett, Aliza Zangwill, Ivan Estevez, Lena Lai
2015, Open-File Report 2015-1099
Vertical one-dimensional shear wave velocity (Vs) profiles are presented for 25 strong-motion instrument sites along the Mid-Atlantic eastern seaboard, Piedmont region, and Appalachian region, which surround the epicenter of the M5.8 Mineral, Virginia, Earthquake of August 23, 2011. Testing was performed at sites in Pennsylvania, Maryland, West Virginia, Virginia, the...
Temperature profile around a basaltic sill intruded into wet sediments
Leslie Baker, Andrew Bernard, William C. Rember, Moses P. Milazzo, Colin M. Dundas, Oleg Abramov, Laszlo P. Keszthelyi
2015, Journal of Volcanology and Geothermal Research (302) 81-86
The transfer of heat into wet sediments from magmatic intrusions or lava flows is not well constrained from field data. Such field constraints on numerical models of heat transfer could significantly improve our understanding of water–lava interactions. We use experimentally calibrated pollen darkening to measure the temperature profile around a...
The mysterious wolves of Belarus
Shannon Barber-Meyer
2015, International Wolf 22-24
It was just after 3 a.m. as we very quietly exited the van, making sure our water-resistant clothes didn’t make too much noise. A wolf researcher howled into the cold and murky mist. We waited in darkness, hoping for an answer. A single wolf howl from about 300 meters in...
Observational data on the effects of infection by the copepod Salmincola californiensis on the short- and long-term viability of juvenile Chinook salmon (Oncorhynchus tshawytscha) implanted with telemetry tags
John W. Beeman, Amy C. Hansen, Jamie M. Sprando
2015, Animal Biotelemetry (3) 1-7
Background Fish movements are often studied using radio or acoustic tags assuming the handling and tagging procedures have little effect on the behavior of the animal. Indeed, many studies provide guidelines for acceptable methods. However, these studies generally assume the fish are otherwise healthy but this may not...
Novel associations between contaminant body burdens and biomarkers of reproductive condition in male Common Carp along multiple gradients of contaminant exposure in Lake Mead National Recreation Area, USA
Reynaldo Patino, Matthew M. VanLandeghem, Steven L. Goodbred, Erik Orsak, Jill A. Jenkins, Kathy R. Echols, Michael R. Rosen, Leticia Torres
2015, General and Comparative Endocrinology (219) 112-124
Adult male Common Carp were sampled in 2007/08 over a full reproductive cycle at Lake Mead National Recreation Area. Sites sampled included a stream dominated by treated wastewater effluent, a lake basin receiving the streamflow, an upstream lake basin (reference), and a site below Hoover Dam. Individual body burdens for...
Similarities and differences in 13C and 15N stable isotope ratios in two non-lethal tissue types from shovelnose sturgeon Scaphirhynchus platorynchus (Rafinesque, 1820)
R. J. DeVries, Harold L. Schramm Jr.
2015, Journal of Applied Ichthyology (31) 474-478
We tested the hypothesis that δ13C and δ15N signatures of pectoral spines would provide measures of δ13C and δ15N similar to those obtained from fin clips for adult shovelnose sturgeon Scaphirhynchus platorynchus. Thirty-two shovelnose sturgeon (fork length [FL] = 500–724 mm) were sampled from the lower Mississippi River, USA on 23 February 2013. Isotopic...
Genetic diversity is related to climatic variation and vulnerability in threatened bull trout
Ryan Kovach, Clint C. Muhlfeld, Alisa A. Wade, Brian K. Hand, Diane C. Whited, Patrick W. DeHaan, Robert K. Al-Chokhachy, Gordon Luikart
2015, Global Change Biology (21) 2510-2524
Understanding how climatic variation influences ecological and evolutionary processes is crucial for informed conservation decision-making. Nevertheless, few studies have measured how climatic variation influences genetic diversity within populations or how genetic diversity is distributed across space relative to future climatic stress. Here, we tested whether patterns of genetic diversity (allelic...
The Effect of modeled recharge distribution on simulated groundwater availability and capture
Fred D. Tillman, Donald R. Pool, Stanley A. Leake
2015, Groundwater (53) 378-388
Simulating groundwater flow in basin-fill aquifers of the semiarid southwestern United States commonly requires decisions about how to distribute aquifer recharge. Precipitation can recharge basin-fill aquifers by direct infiltration and transport through faults and fractures in the high-elevation areas, by flowing overland through high-elevation areas to infiltrate at basin-fill margins...
