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At least 1,081 records · Page 60Linked to original sources
USGS2006

Profile of microflora of the posterior intestine of Chinook salmon before, during, and after administration of rations with and without erythromycin

We describe the resident heterotrophic aerobic microflora of the salmonid posterior intestine before, during, and after the administration of rations with erythromycin in a hatchery raceway environment. We compare the profiles of medicated Chinook salmon Oncorhynchus tshawytscha with those of control fish that were not fed erythromycin. The combined counts of bacteria and yeasts per gram of fish intestine originating from four upstream raceways ranged from 3.0 ?? 102 to 9.6 ?? 105 colony-forming units (CFU) over the study period. Yeasts were commonly identified in the gut, and abundances ranged from 0% to more than 80% of the CFU. Erythromycin therapy decreased the total microbial population and altered the bacterial diversity in the gut during treatment. The intestinal microbial populations in fish medicated with erythromycin increased rapidly after treatment ceased, and by 25 d after treatment the CFU were similar in samples from both medicated and control fish populations. Of 325 isolates from fish selected for biochemical profiles, we identified a total of eight gram-positive and eight gram-negative genera. Bacillus spp. were common throughout sampling and were identified in samples of fish feed. Erythromycin-resistant, gram-positive bacteria were observed throughout the sampling in medicated and control fish. We identified seven gram-positive and two gram-negative genera in 74 selected isolates from control and erythromycin feeds. Our studies suggest that the aerobic microflora of the posterior intestine varies over time, and it is likely that few resistant genera of concern to human health are present.

Conference Paper↗
USGS2003

Status and interconnections of selected environmental issues in the global coastal zones

This study focuses on assessing the state of population distribution, land cover distribution, biodiversity hotspots, and protected areas in global coastal zones. The coastal zone is defined as land within 100 km of the coastline. This study attempts to answer such questions as: how crowded are the coastal zones, what is the pattern of land cover distribution in these areas, how much of these areas are designated as protected areas, what is the state of the biodiversity hotspots, and what are the interconnections between people and coastal environment. This study uses globally consistent and comprehensive geospatial datasets based on remote sensing and other sources. The application of Geographic Information System (GIS) layering methods and consistent datasets has made it possible to identify and quantify selected coastal zones environmental issues and their interconnections. It is expected that such information provide a scientific basis for global coastal zones management and assist in policy formulations at the national and international levels.

Ambio↗
USGS1994

Geologic studies in Alaska by the U.S. Geological Survey, 1993

This collection of 19 papers continues the annual series of U.S. Geological Survey reports on geologic investigations in Alaska. Contributions include 14 Articles and 5 shorter Geologic Notes that report results from all corners of the State. USGS activities in Alaska cover a broad spectrum of earth science topics, including the environment, hazards, resources, and geologic framework studies. Three articles focus on the environmental geochemistry of parts of south-central, west-central, and southwestern Alaska. An article on methane released from permafrost near Fairbanks and a note on paleowind direction indicators on the Arctic coastal plain contribute to ongoing climate and paleoclimate investigations. Landslide hazards in the Talkeetna Mountains and Wrangell-St. Elias National Park are discussed in two notes. Possible active fault traces near Alaska's main population center are described in an article on the Castle Mountain fault. An article on Aniakchak volcano presents evidence for a previously unrecognized catastrophic flooding event. Resources and resource assessment on gold, base metals, and coal are discussed in several articles and a note. Geologic framework studies cover tectonics, paleontology, stratigraphy, and metamorphic petrology. One contribution involves field methods; it evaluates the relative accuracy of global positioning systems and topographic map-based methods for deriving location data for field stations. Two bibliographies at the end of the volume list reports about Alaska in USGS publications released in 1993 and reports about Alaska by USGS authors in non-USGS publications in 1993.

Alaska↗
USGS2018

Public-supply water use and self-supplied industrial water use in Tennessee, 2010

The U.S. Geological Survey (USGS), in cooperation with the Tennessee Department of Environment and Conservation, Division of Water Resources, prepared this report and displayed and analyzed water use by self-supplied industrial and public-supply water systems in Tennessee for 2010. Public-supply water systems in Tennessee provide water for domestic, industrial, and commercial uses and for municipal services. In 2010, 474 public-supply water systems distributed 917 million gallons per day (Mgal/d) of surface water (67 percent, 617 Mgal/d) and groundwater (33 percent, 300 Mgal/d) to a population of 5.7 million in Tennessee. Gross per capita water use in Tennessee during 2010 was 162 gallons per day. Since 1950, water withdrawals by public-supply water systems in Tennessee have increased from 160 Mgal/d to 917 Mgal/d in 2010. Each of the 95 counties in Tennessee was served by at least 1 public-supply water system in 2010. Tennessee public-supply water systems withdraw less groundwater than surface water, and surface-water use has increased at a faster rate than groundwater use. Since 2005, surface-water withdrawals have increased by 26 Mgal/d, and groundwater withdrawals have decreased by 29 Mgal/d, which is the first decrease in groundwater withdrawals since 1950; however, 29 systems reported increased groundwater withdrawals during 2010, and 12 of these 29 systems reported increases of 1 Mgal/d or more. Davidson County had the largest surface-water withdrawal rate (136 Mgal/d) in 2010. The largest groundwater withdrawal rate (151 Mgal/d) by a single public-supply water system was reported by Memphis Light, Gas and Water, which served more than 669,000 people in Shelby County in 2010. Self-supplied industrial water use includes water for such purposes as fabrication, processing, washing, diluting, cooling, or transporting a product; incorporating water into a product; or for sanitation needs in facilities that manufacture various products. Water withdrawals for self-supplied industrial water use during 2010 were about 776 Mgal/d. This quantity represented a decrease of 7 Mgal/d since 2005. In Tennessee, self-supplied industrial water withdrawals were primarily for chemical and allied products (555 Mgal/d), paper and allied products (107 Mgal/d), aeronautical products (71.5 Mgal/d), concrete and glass products (9.74 Mgal/d), and primary metal products (4.49 Mgal/d); and these products accounted for 96 percent (747 Mgal/d) of the self-supplied industrial water withdrawals in 2010. Surface water supplied 94 percent of the water (728 Mgal/d) for self-supplied industrial purposes, and groundwater supplied 6 percent (47.6 Mgal/d). Self-supplied industrial water withdrawals in Sullivan County were 488 Mgal/d and accounted for 61 percent of the self-supplied industrial water withdrawals. The largest groundwater withdrawal, 14.9 Mgal/d, by a single self-supplied industry was in Memphis, Tennessee, for the production of chemicals and allied products.

Tennessee↗
USGS1995

Sidescan-sonar surveys of critical habitats in Long Island Sound, Connecticut

The Long Island Sound estuary is located in the most densely populated region of the U.S.. Due to the enormous surrounding population, large inputs of anthropogenic wastes and toxic chemicals, benthic habitats were degraded. To address this environmental problem, sidescan-sonar mosaics are being developed within specific areas of critical concern. Detailed bathymetric and high-resolution seismic-reflection data assist in interpretations of relief, to relate bottom features to the underlying stratigraphy, and to estimate thicknesses of surficial sediments. To date, several continuous-coverage sidescan-sonar surveys have been completed. These surveys show that the sedimentary environments and benthic habitats in Long Island Sound vary spatially over short distances.

Conference Paper↗
USGS2013

The conservation status of the world’s reptiles

Effective and targeted conservation action requires detailed information about species, their distribution, systematics and ecology as well as the distribution of threat processes which affect them. Knowledge of reptilian diversity remains surprisingly disparate, and innovative means of gaining rapid insight into the status of reptiles are needed in order to highlight urgent conservation cases and inform environmental policy with appropriate biodiversity information in a timely manner. We present the first ever global analysis of extinction risk in reptiles, based on a random representative sample of 1500 species (16% of all currently known species). To our knowledge, our results provide the first analysis of the global conservation status and distribution patterns of reptiles and the threats affecting them, highlighting conservation priorities and knowledge gaps which need to be addressed urgently to ensure the continued survival of the world’s reptiles. Nearly one in five reptilian species are threatened with extinction, with another one in five species classed as Data Deficient. The proportion of threatened reptile species is highest in freshwater environments, tropical regions and on oceanic islands, while data deficiency was highest in tropical areas, such as Central Africa and Southeast Asia, and among fossorial reptiles. Our results emphasise the need for research attention to be focussed on tropical areas which are experiencing the most dramatic rates of habitat loss, on fossorial reptiles for which there is a chronic lack of data, and on certain taxa such as snakes for which extinction risk may currently be underestimated due to lack of population information. Conservation actions specifically need to mitigate the effects of human-induced habitat loss and harvesting, which are the predominant threats to reptiles.

Biological Conservation↗
USGS1976

The environment of South Florida; a summary report

Man has altered the original south Florida ecosystem to a new three-part ecosystem which incorporates an agricultural component, an urban component, and a component of the original ecosystem that is largely unchanged but still has been affected by man. These components are interrelated through the flow of energy and material. The ecosystem of south Florida has undergone extensive alteration for 70 years. About 35 percent (3 ,000 square miles) of the original habitat of the ecosystem has been replaced by agriculture or urbanization. The remaining natural habitat is stressed by exotic plants and animal, changes in water levels and flows, severe fires, pollution, loss of animal and plant populations, and by further growth and development. Man 's most dramatic and long-term effects on the ecosystem have resulted from drainage. Wetlands originally occupied about 75 percent of south Florida; through the years large areas of this land have been drained. In parts of southeast Florida, drainage has lowered water levels 5 to 6 feet below the 1900 level and stressed natural systems. (Woodard-USGS)

Professional Paper↗
USGS2022

Similar environmental conditions are associated with Walleye and Yellow Perch recruitment success in Wisconsin lakes

Since the mid-2000s, recruitment of Walleye Sander vitreus in some northern Wisconsin lakes has declined, potentially because of climate-induced changes in lake environments. Yellow Perch Perca flavescens is also an ecologically and culturally important fish species in this region, but mechanisms driving Yellow Perch recruitment are unclear because of a lack of targeted sampling. Previous studies have suggested that recruitment of these two species may be regulated by similar factors, and observed declines in Walleye recruitment may be cause for concern about Yellow Perch recruitment. Our objectives were to determine if abiotic factors related to recruitment success were similar between Walleye and Yellow Perch populations in northern Wisconsin lakes and if the probability of successful Walleye recruitment was related to estimates of juvenile Yellow Perch abundance before Walleye recruitment declines were observed. We addressed these objectives using historical data from Wisconsin lakes. Random forest analysis incorporating lake-specific averages of predictor variables indicated that winter conditions (duration or severity), growing degree days, variation in spring temperatures, peak summer temperature, and Secchi depth were important predictors of recruitment success for both species. Logistic regression indicated that before Walleye recruitment declines were observed on some lakes (2000–2006), Walleye recruitment success was related to relative abundance of juvenile Yellow Perch in mini-fyke-net sampling. Our results indicate that landscape-level patterns in recruitment success for the two species are likely similar and additional research to understand Yellow Perch recruitment trends is warranted. Better information on Yellow Perch recruitment could contribute to a better understanding of Walleye recruitment trends as declines in Yellow Perch could influence prey availability and survival of age-0 Walleye. Furthermore, potential declines in Yellow Perch could lead to changes in the numbers and size of Yellow Perch caught by anglers, which may have implications for harvest management.

Wisconsin↗
USGS2010

North American osprey populations and contaminants: Historic and contemporary perspectives

Osprey ( Pandion haliaetus ) populations were adversely affected by DDT and perhaps other contaminants in the United States and elsewhere. Reduced productivity, eggshell thinning, and high DDE concentrations in eggs were the signs associated with declining osprey populations in the 1950s, 1960s, and 1970s. The species was one of the first studied on a large scale to bring contaminant issues into focus. Although few quantitative population data were available prior to the 1960s, many osprey populations in North America were studied during the 1960s and 1970s with much learned about basic life history and biology. This article reviews the historical and current effects of contaminants on regional osprey populations. Breeding populations in many regions of North America showed post-DDT-era (1972) population increases of varying magnitudes, with many populations now appearing to stabilize at much higher numbers than initially reported in the 1970s and 1980s. However, the magnitude of regional population increases in the United States between 1981 (first Nationwide Survey, ∼8,000 pairs), when some recovery had already occurred, 1994 (second survey, ∼14,200), and 2001 (third survey, ∼16,000–19,000), or any other years, is likely not a simple response to the release from earlier contaminant effects, but a response to multi-factorial effects. This indirect “contaminant effects” measurement comparing changes (i.e., recovery) in post-DDT-era population numbers over time is probably confounded by changing human attitudes toward birds of prey (shooting, destroying nests, etc.), changing habitats, changing fish populations, and perhaps competition from other species. The species' adaptation to newly created reservoirs and its increasing use of artificial nesting structures (power poles, nesting platforms, cell towers, channel markers, offshore duck blinds, etc.) are two important factors. The timing of the initial use of artificial nesting structures, which replaced declining numbers of suitable trees at many locations, varied regionally (much later in the western United States and Mexico). Because of the increasing use of artificial nesting structures, there may be more ospreys nesting in North America now than ever before. Now, with the impact of most legacy organic contaminants (DDT, other organochlorine [OC] pesticides, polychlorinated biphenyls [PCB], polychlorinated dibenzo- p -dioxins [PCDD], polychlorinated dibenzofurans (PCDF]) greatly reduced or eliminated, and some osprey populations showing evidence of stabilizing, the species was proposed as a Worldwide Sentinel Species for evaluating emerging contaminants. Several emerging contaminants are already being studied, such as polybrominated diphenyl ethers (PBDE) and perfluorinated acids and sulfonate compounds (PFC). The many advantages for continued contaminant investigations using the osprey include a good understanding of its biology and ecology, its known distribution and abundance, and its ability to habituate to humans and their activities, which permits nesting in some of the potentially most contaminated environments. It is a top predator in most ecosystems, and its nests are relatively easy to locate and study with little researcher impact on reproductive success.

Journal of Toxicology and Environmental Health, Pa↗
USGS2016

Ungulate reproductive parameters track satellite observations of plant phenology across latitude and climatological regimes

The effect of climatically-driven plant phenology on mammalian reproduction is one key to predicting species-specific demographic responses to climate change. Large ungulates face their greatest energetic demands from the later stages of pregnancy through weaning, and so in seasonal environments parturition dates should match periods of high primary productivity. Interannual variation in weather influences the quality and timing of forage availability, which can influence neonatal survival. Here, we evaluated macro-scale patterns in reproductive performance of a widely distributed ungulate (mule deer, Odocoileus hemionus ) across contrasting climatological regimes using satellite-derived indices of primary productivity and plant phenology over eight degrees of latitude (890 km) in the American Southwest. The dataset comprised > 180,000 animal observations taken from 54 populations over eight years (2004–2011). Regionally, both the start and peak of growing season (“Start” and “Peak”, respectively) are negatively and significantly correlated with latitude, an unusual pattern stemming from a change in the dominance of spring snowmelt in the north to the influence of the North American Monsoon in the south. Corresponding to the timing and variation in both the Start and Peak, mule deer reproduction was latest, lowest, and most variable at lower latitudes where plant phenology is timed to the onset of monsoonal moisture. Parturition dates closely tracked the growing season across space, lagging behind the Start and preceding the Peak by 27 and 23 days, respectively. Mean juvenile production increased, and variation decreased, with increasing latitude. Temporally, juvenile production was best predicted by primary productivity during summer, which encompassed late pregnancy, parturition, and early lactation. Our findings offer a parsimonious explanation of two key reproductive parameters in ungulate demography, timing of parturition and mean annual production, across latitude and changing climatological regimes. Practically, this demonstrates the potential for broad-scale modeling of couplings between climate, plant phenology, and animal populations using space-borne observations.

Arizona, Colorado, Utah↗
USGS1990

National Coastal Geology Program: a plan of geologic research on coastal erosion, coastal wetlands, polluted sediments, and coastal hard-mineral resources

More than 50 percent of the U.S. population currently live within 50 miles of an ocean, Great Lake, or major estuary. According to forecasts, the concentration of people along our coastlines will continue to increase into the 21st century. In addition to residential and commercial buildings and facilities worth tens of billions of dollars, the coasts and associated wetlands are natural resources of tremendous value, with estimates in excess of $13 billion per year for commercial and recreational fisheries alone. Human activities and natural processes are stressing the coastal environment. * Each of the coastal states and island territories is suffering problems related to coastal erosion. * Deterioration of wetlands is widespread and of great public concern. * Pollutants carried by rivers or runoff are discharged directly into coastal waters and accumulate in the sediments on the sea floor, in some areas causing damage to living resources and presenting a threat to public health. * Onshore sources for hard-mineral resources, such as sand and gravel used for construction purposes, are becoming increasingly difficult to find. New sources are being sought in coastal waters. Coastal issues will become even more important into the next century if sea level is significantly influenced by climate change and other factors.

Monograph↗
USGS2002

Preliminary hydrogeologic assessment and study plan for a regional ground-water resource investigation of the Blue Ridge and Piedmont provinces of North Carolina

Prolonged drought, allocation of surface-water flow, and increased demands on ground-water supplies resulting from population growth are focuses for the need to evaluate ground-water resources in the Blue Ridge and Piedmont Provinces of North Carolina. Urbanization and certain aspects of agricultural production also have caused increased concerns about protecting the quality of ground water in this region. More than 75 percent of the State's population resides in the Blue Ridge and Piedmont Provinces in an area that covers 30,544 square miles and 65 counties. Between 1940 and 2000, the population in the Piedmont and Blue Ridge Provinces increased from 2.66 to 6.11 million; most of this increase occurred in the Piedmont. Of the total population, an estimated 1.97 million people, or 32.3 percent (based on the 1990 census), relied on ground water for a variety of uses, including commercial, industrial, and most importantly, potable supplies. Ground water in the Blue Ridge and Piedmont traditionally has not been considered as a source for large supplies, primarily because of readily available and seemingly limitless surface-water supplies, and the perception that ground water in the Blue Ridge and Piedmont Provinces occurs in a complex, generally heterogeneous geologic environment. Some reluctance to use ground water for large supplies derives from the reputation of aquifers in these provinces for producing low yields to wells, and the few high-yield wells that are drilled seem to be scattered in areas distant from where they are needed. Because the aquifers in these provinces are shallow, they also are susceptible to contamination by activities on the land surface. In response to these issues, the North Carolina Legislature supported the creation of a Resource Evaluation Program to ensure the long-term availability, sustainability, and quality of ground water in the State. As part of the Resource Evaluation Program, the North Carolina Division of Water Quality, Groundwater Section, in cooperation with the U.S. Geological Survey, initiated a multiyear study of ground water in the Blue Ridge and Piedmont Provinces. The study began in 1999. Most of the study area is underlain by a complex, two-part, regolith-fractured crystalline rock aquifer system. Thickness of the regolith throughout the study area is highly variable and ranges from 0 to more than 150 feet. The regolith consists of an unconsolidated or semiconsolidated mixture of clay and fragmental material ranging in grain size from silt to boulders. Because porosities range from 35 to 55 percent, the regolith provides the bulk of the water storage within the Blue Ridge and Piedmont ground-water system. At the base of the regolith is the transition zone where saprolite grades into unweathered bedrock. The transition zone has been identified as a potential conduit for rapid ground-water flow. If this is the case, the transition zone also may serve as a conduit for rapid movement of contaminants to nearby wells or to streams with channels that cut into 1 U.S. Geological Survey, Raleigh, North Carolina. 2 North Carolina Department of Environment and Natural Resources, Division of Water Quality, Groundwater Section. or through the transition zone. How rapidly a contaminant moves through the system largely may be a function of the characteristics of the transition zone. The transition zone is one of several topics identified during the literature review and data synthesis, for which there is a deficiency in data and understanding of the processes involved in the movement of ground water to surface water. Because the Blue Ridge and Piedmont study area is so large, and the hydrogeology diverse, it is not feasible to study all of the area in detail. A more feasible approach is to select areas that are most representative of the land use, geology, and hydrology to obtain an understanding of the hydrologic processes in the selected areas, and transfer the knowledge from these local "type areas" to similar regional hydrogeologic areas. For the purpose of this study, the term "type area" applies to a 10- to 100-square mile area within a hydrogeologic terrane where information is sufficient to develop and test a concept of ground-water flow by using analytical or numerical methods that can be validated by field measurements. Ideally, these type areas are selected to be representative of the flow system that is present wherever a particular hydrogeologic terrane is present. This report consists of two basic parts. The first part describes the results of a comprehensive review and synthesis of information and literature that provides the basic background for the study. This includes current (2002) knowledge regarding general geology and the hydrogeologic framework of the fractured-rock aquifer system that underlies the Blue Ridge and Piedmont Provinces. In spite of the quantity of information identified during the literature review and the amount of past work that has been documented, there are still research needs to be met. The second part of the report describes State ground-water issues and problems, available data, and data deficiencies. It also describes the design and implementation of efforts to characterize ground-water quality and to quantify factors that influence the movement and availability of ground water in the hydrogeologic terranes characterized by (1) massive or foliated crystalline rocks overlain by thick regolith and (2) massive or foliated crystalline rocks overlain by thin regolith. As of September 2001, seven sites had been identified as potential study sites to be used to characterize the hydrogeology and water quality of ype areas considered representative of the larger terranes. Detailed geologic mapping, core drilling, well installation, and surface and borehole geophysical surveys are in progress at four of the sites.

North Carolina↗
USGS2022

An integrated approach for physical, economic, and demographic evaluation of coastal flood hazard adaptation in Santa Monica Bay, California

The increased risk of coastal flooding associated with climate-change driven sea level rise threatens to displace communities and cause substantial damage to infrastructure. Site-specific adaptation planning is necessary to mitigate the negative impacts of flooding on coastal residents and the built environment. Cost-benefit analyses used to evaluate coastal adaption strategies have traditionally focused on economic considerations, often overlooking potential demographic impacts that can directly influence vulnerability in coastal communities. Here, we present a transferable framework that couples hydrodynamic modeling of flooding driven by sea level rise and storm scenarios with site-specific building stock and census block-level demographic data. We assess the efficacy of multiple coastal adaptation strategies at reducing flooding, economic damages, and impacts to the local population. We apply this framework to evaluate a range of engineered, nature-based, and hybrid adaptation strategies for a portion of Santa Monica Bay, California. Overall, we find that dual approaches that provide protection along beaches using dunes or seawalls and along inlets using sluice gates perform best at reducing or eliminating flooding, damages, and population impacts. Adaptation strategies that include a sluice gate and partial or no protection along the beach are effective at reducing flooding around inlets but can exacerbate flooding elsewhere, leading to unintended impacts on residents. Our results also indicate trade-offs between economic and social risk-reduction priorities. The proposed framework allows for a comprehensive evaluation of coastal protection strategies across multiple objectives. Understanding how coastal adaptation strategies affect hydrodynamic, economic, and social factors at a local scale can enable more effective and equitable planning approaches.

California↗
USGS1993

Geologic research in support of sustainable agriculture

The importance and role of the geosciences in studies of sustainable agriculture include such traditional research areas as, agromineral resource assessments, the mapping and classification of soils and soil amendments, and the evaluation of landscapes for their vulnerability to physical and chemical degradation. Less traditional areas of study, that are increasing in societal importance because of environmental concerns and research into sustainable systems in general, include regional geochemical studies of plant and animal trace element deficiencies and toxicities, broad-scale water quality investigations, agricultural chemicals and the hydrogeologic interface, and minimally processed and ion-exchange agrominerals. We discuss the importance and future of phosphate in the US and world based on human population growth, projected agromineral demands in general, and the unavailability of new, high-quality agricultural lands. We also present examples of studies that relate geochemistry and the hydrogeologic characteristics of a region to the bioavailability and cycling of trace elements important to sustainable agricultural systems.

Agriculture, Ecosystems and Environment↗
USGS2023

Parallel shifts in trout feeding morphology suggest rapid adaptation to alpine lake environments

Eco-evolutionary interactions following ecosystem change provide critical insight into the ability of organisms to adapt to shifting resource landscapes. Here we explore evidence for the rapid parallel evolution of trout feeding morphology following eco-evolutionary interactions with zooplankton in alpine lakes stocked at different points in time in the Wind River Range (Wyoming, USA). In this system, trout predation has altered the zooplankton species community and driven a decrease in average zooplankton size. In some lakes that were stocked decades ago, we find shifts in gill raker traits consistent with the hypothesis that trout have rapidly adapted to exploit available smaller-bodied zooplankton more effectively. We explore this morphological response in multiple lake populations across two species of trout (cutthroat trout, Oncorhynchus clarkii , and golden trout Oncorhynchus aguabonita ) and examine the impact of resource availability on morphological variation in gill raker number among lakes. Furthermore, we present genetic data to provide evidence that historically stocked cutthroat trout populations likely derive from multiple population sources, and incorporate variation from genomic relatedness in our exploration of environmental predictors of feeding morphology. These findings describe rapid adaptation and eco-evolutionary interactions in trout and document an evolutionary response to novel, contemporary ecosystem change.

Evolution↗
USGS2012

Differences in survival and growth in hatchery and stream environments, and in maturation of residuls in a stream, between progeny of hatchery and wild steelhead (Study sites: Brushy Fork Creek and Dworshak Hatchery; Stocks:Dworshak hatchery and Fish Creek wild; Year classes: 1992 and 1993)

Freshwater survival in hatchery and natural rearing environments was compared between progeny of hatchery (H) and wild (W) steelhead Oncorhynchus mykiss from the Clearwater River drainage in Idaho. Adults from Dworshak National Fish Hatchery and wild adults from Fish Creek fish were artificially spawned, and their progeny were genetically marked at the PEPA allozyme locus and released together as unfed fry in production facilities at the hatchery and in Brushy Fork Creek, also in the Clearwater River drainage, in a common garden design. Survival was higher for H than for W progeny at the hatchery but lower for H than for W progeny in Brushy Fork, indicating reduced fitness of the hatchery population for natural rearing and suggesting domestication as the cause. Survival at the hatchery was lower than is typical due to disease outbreaks. Survival of the first year-class of experimental fish to smolt release was only 18%. Survival of H fish was 3.8 times that of W fish under these poor survival conditions. All fish from the second year-class died halfway through the scheduled 10 month rearing period. Survival of H fish was 5.2 times that of W fish to when 1% of the initial fry were still alive indicating that W fish succumbed to the epizootic sooner than did H fish. Emigrants from the Brushy Fork study reach were sampled for three years and fish residing in the study reach were sampled for six years following fry release. Most emigrants were one or two years old and too small to be smolts (mean fork length at age-2 = 93 mm). Survival in Brushy Fork was lower for H than for W fish of the first year-class. Survival of the second year-class was higher for H than for W fish during the first two months in the stream but was lower for H than for W fish thereafter, and net survival from release to ages 3 and older was also lower for H than for W fish if our emigrant samples were representative (periods of inoperative emigrant traps prevented certainty about this). Differences between progeny groups were also found for growth (H>W) and condition (H>W) in the hatchery and downstream migration success of hatchery-reared fish after release (H>W), and for growth (H<W for one year-class; H>W for the other), condition (H>W), downstream dispersal (H>W for one year-class; H=W for the other), and maturation of residuals (ovaries weight was greater for H than for W females at ages 4 and 5; testes weight was less for H than for W age-3 males of one year-class) in Brushy Fork. A thunderstorm-induced power outage interrupted flow to the incubation trays at the hatchery and compromised a major tenet of the common garden design for the second year-class, possibly contributing to the inconsistency in relative survivals in Brushy Fork between year-classes. The storm caused the incubation environment to differ between the stocks as a result of reduced oxygen levels and substantially higher densities for H alevins. This difference was illustrated by a 55% loss for H fish during the event, about twice that for W fish.

Idaho↗
USGS2020

Gambel’s quail survey variability and implications for survey design in the Mohave Desert

Careful design of a wildlife population monitoring strategy is necessary to obtain accurate and precise results whether the purpose of the survey is development of habitat suitability models, to estimate abundance, or assess site occupancy. Important characteristics to consider in survey design are sources of elevated variability, particularly within‐subject variability, which increases the amount of data needed to achieve statistical certainty either in terms of population trend analysis, hypothesis testing, or statistical power. However, alternative objectives, such as associating counts with habitat characteristics, may benefit from increased variation among counts when differences covary with habitat measures. This difference can result in competing needs when developing survey protocols. We investigated the relative precision of differing gamebird monitoring protocols to identify methods with the greatest statistical efficiency. We assessed call‐count transects using standard Breeding Bird Survey protocols (Passive call‐counts) and modified by including longer survey periods and call playback (Active call‐counts), autonomous recording units with supervised call detection (ARU‐recorded calls), camera traps, and roadside covey‐counts for Gambel's quail ( Callipepla gambelii ) in the Mojave Desert (CA, USA) during the spring of 2016. Active call‐counts had the lowest within‐site variation relative to estimated population index values, but Passive call‐count transects may be more efficient for some purposes because more survey stations can be completed within a single survey timeframe. The ARU‐recorded calls may provide a suitable alternative despite larger sample size needs, especially for occupancy surveys because multiple units can be deployed concurrently. The ultimate sample size required will depend on specific study objectives and scope of interest, but camera traps and breeding‐season covey counts are not likely to meet objectives in desert environments.

California↗
USGS2014

The geochemistry of deep-sea coral skeletons: a review of vital effects and applications for palaeoceanography

Deep-sea corals were discovered over a century ago, but it is only over recent years that focused efforts have been made to explore the history of the oceans using the geochemistry of their skeletal remains. They offer a promising archive of past oceanic environments given their global distribution, layered growth patterns, longevity and preservation as well as our ability to date them using radiometric techniques. This paper provides an overview of the current state-of-the-art in terms of geochemical approaches to using deep-sea coral skeletons to explore the history of the ocean. Deep-sea coral skeletons have a wide array of morphologies (e.g. solitary cup corals, branching colonial corals) and materials (calcite, aragonite and proteins). As such their biomineralization strategies are diverse, leading to complex geochemistry within coral skeletons. Notwithstanding these complications, progress has been made on developing methods for reconstructing the oceanographic environment in the past using trace elements and isotopic methods. Promising approaches within certain coral groups include clumped isotopes and Mg/Li for temperature reconstructions, boron isotopes and radiocarbon for carbon cycling, εNd, and radiocarbon for circulation studies and δ 15 N, P/Ca and Ba/Ca for nutrient tracer studies. Likewise there is now a range of techniques for dating deep-sea corals skeletons (e.g. U-series, radiocarbon), and determining their growth rates (e.g. radiocarbon and 210 Pb). Dating studies on historic coral populations in the Atlantic, Southern Ocean and Pacific point to climate and environmental changes being dominant controls on coral populations over millennial and orbital timescales. This paper provides a review of a range of successes and promising approaches. It also highlights areas in which further research would likely provide new insights into biomineralization, palaeoceanography and distribution of past coral populations.

Deep-Sea Research Part II: Topical Studies in Ocea↗