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At least 235 records · Page 13Linked to original sources
USGS2021

Nest microclimate and limits to egg viability explain avian life-history variation across latitudinal gradients

Variation in life-history strategies is central to our understanding of population dynamics and how organisms adapt to their environments. Yet, we lack consensus regarding the ecological processes that drive variation in traits related to reproduction and survival. For example, we still do not understand the cause of two widespread inter- and intraspecific patterns: 1) the ubiquitous positive association between avian clutch size and latitude, and 2) variation in the extent of asynchronous hatching of eggs within a single clutch. Well-known hypotheses to explain each pattern have largely focused on biotic processes related to food availability and predation risk. However, local adaptation to maintain egg viability could explain both patterns with a single abiotic mechanism. The egg viability hypothesis was proposed to explain the cause of asynchronous hatching and suggests that asynchronous hatching results from early incubation onset in response to unfavorable nest microclimatic conditions, which otherwise reduce egg viability, and that early incubation onset may energetically constrain clutch size. We measured intraspecific variation in five functionally-linked life-history traits of Burrowing Owls at five study sites spanning a 1400-km latitudinal transect in western North America: clutch size, the timing of incubation onset, the degree of hatching asynchrony, the probability of hatching failure, and nestling survival. We found that most traits varied clinally with latitude, but all the traits were more strongly associated with individual nest microclimates than with latitude, and all varied with nest microclimate in the direction predicted by the egg viability hypothesis. Furthermore, incubation began earlier, hatching asynchrony increased, and clutch size declined across the breeding season. These results suggest that nest microclimate drives an important life-history tradeoff and that thermal gradients are often sufficient to account for observed biogeographic and seasonal patterns in life-history strategies. Furthermore, our results reveal a potentially important indirect mechanism by which reproductive success and recruitment could be affected by climate change.

Ecology↗
USGS2024

Egg mercury concentration and egg size varies with position in the laying sequence in two songbird species

In birds, mercury embryotoxicity can occur through the transfer of mercury from the female to her eggs. Maternal transfer of mercury can vary by egg position in the laying sequence, with first-laid eggs often exhibiting greater mercury concentrations than subsequently laid eggs. We studied egg mercury concentration, mercury burden (total amount of mercury in the egg), and egg morphometrics by egg position in the laying sequence for two songbirds: tree swallows ( Tachycineta bicolor ) and house wrens ( Troglodytes aedon ). Egg mercury concentration in the second egg laid was 14% lower for tree swallows and 6% lower for house wrens in comparison with the first egg laid. These results indicate that in both species, after an initial relatively high transfer of mercury into the first egg laid, a smaller amount of mercury was transferred to the second egg laid. This lower mercury concentration persisted among all subsequently laid eggs (eggs three to eight) in tree swallows (all were 14%–16% lower than egg 1), but mercury concentrations in subsequently laid house wren eggs (eggs three to seven) returned to levels observed in the first egg laid (all were 1% lower to 3% greater than egg 1). Egg size increased with position in the laying sequence in both species; the predicted volume of egg 7 was 5% and 6% greater than that of egg 1 in tree swallows and house wrens, respectively. This change was caused by a significant increase in egg width, but not egg length, with position in the laying sequence. The percentage of decline in mercury concentration with position in the laying sequence was considerably lower in tree swallows and house wrens compared with other bird taxonomic groups, suggesting that there are key differences in the maternal transfer of mercury into songbird eggs compared with other birds. Finally, we performed simulations to evaluate how within-clutch variation in egg mercury concentrations affected estimates of mean mercury concentrations in each clutch and the overall sampled population, which has direct implications for sampling designs. Environ Toxicol Chem 2024;00:1–11. Published 2024. This article is a U.S. Government work and is in the public domain in the USA.

Environmental Toxicology and Chemistry↗
USGS2013

Environmental impact of the landslides caused by the 12 May 2008, Wenchuan, China earthquake

The magnitude 7.9 (M w ) Wenchuan, China, earthquake of May 12, 2008 caused at least 88,000 deaths of which one third are estimated to be due to the more than 56,000 earthquake-induced landslides. The affected area is mountainous, featuring densely-vegetated, steep slopes through which narrowly confined rivers and streams flow. Numerous types of landslides occurred in the area, including rock avalanches, rock falls, translational and rotational slides, lateral spreads and debris flows. Some landslides mobilized hundreds of million cubic meters of material, often resulting in the damming of rivers and streams, impacting river ecosystems and morphology. Through an extensive search of both Chinese- and English-language publications we provide a summary of pertinent research on environmental effects, emphasizing key findings. Environmental effects caused by landslides include the alteration of agriculture, changes to natural ecosystems, changes in river morphology due to landslide dams and other effects such as sedimentation and flooding. Damage by landslides to the giant panda reserve infrastructure and habitat, was severe, threatening the survival of one of the world’s rarest species. The Panda reserves are of national significance to China, and to the vital tourism economy of the region. One of the major impacts to both the natural and built environment is the complete relocation of some human populations and infrastructure to new areas, resulting in the abandonment of towns and other areas that were damaged by the earthquake and landslides. The landslide effects have affected the biodiversity of the affected area, and it has been hypothesized that strict forest preservation measures taken in the years preceding the earthquake resulted in a reduction of the environmental damage to the area.

Wenchuan↗
USGS1990

Small mammal populations at hazardous waste disposal sites near Houston, Texas, USA

Small mammals were trapped, tagged and recaptured in 0?45 ha plots at six hazardous industrial waste disposal sites to determine if populations, body mass and age structures were different from paired control site plots. Low numbers of six species of small mammals were captured on industrial waste sites or control sites. Only populations of hispid cotton rats at industrial waste sites and control sites were large enough for comparisons. Overall population numbers, age structure, and body mass of adult male and female cotton rats were similar at industrial waste sites and control sites. Populations of small mammals (particularly hispid cotton rats) may not suffice as indicators of environments with hazardous industrial waste contamination.

Environmental Pollution↗
USGS2014

Influence of fuels, weather and the built environment on the exposure of property to wildfire

Wildfires can pose a significant risk to people and property. Billions of dollars are spent investing in fire management actions in an attempt to reduce the risk of loss. One of the key areas where money is spent is through fuel treatment – either fuel reduction (prescribed fire) or fuel removal (fuel breaks). Individual treatments can influence fire size and the maximum distance travelled from the ignition and presumably risk, but few studies have examined the landscape level effectiveness of these treatments. Here we use a Bayesian Network model to examine the relative influence of the built and natural environment, weather, fuel and fuel treatments in determining the risk posed from wildfire to the wildland-urban interface. Fire size and distance travelled was influenced most strongly by weather, with exposure to fires most sensitive to changes in the built environment and fire parameters. Natural environment variables and fuel load all had minor influences on fire size, distance travelled and exposure of assets. These results suggest that management of fuels provided minimal reductions in risk to assets and adequate planning of the changes in the built environment to cope with the expansion of human populations is going to be vital for managing risk from fire under future climates.

PLoS ONE↗
USGS2023

Integrated science strategy for assessing and monitoring water availability and migratory birds for terminal lakes across the Great Basin, United States

Executive Summary In 2022, the U.S. Geological Survey (USGS) established the Saline Lake Ecosystems Integrated Water Availability Assessment (IWAAs) to monitor and assess the hydrology of terminal lakes in the Great Basin and the migratory birds and other wildlife dependent on those habitats. Scientists from across the USGS (with specialties in water quantity, water quality, limnology, avian biology, data science, landscape ecology, and science communication) formed the Saline Lake Ecosystems IWAAs Team. The team has developed this regional strategic science plan to guide data collection and assessment activities at terminal lakes in the Great Basin. The U.S. Congress requested the USGS to establish the Saline Lake Ecosystems IWAAs in response to historically low water levels at terminal lakes and associated wetlands across the Great Basin. Not all Great Basin terminal lakes have high salinity; however, all terminal lakes occur in endorheic, closed, basins with no surface-water outflow. Low lake levels across the Great Basin are the result of increased water use for agriculture and municipalities, drought conditions, and a warming climate. Great Basin terminal lake water extents have decreased by as much as 90 percent over the last 150 years, and terminal lake wetlands have decreased in area by as much as 47 percent since 1984. Lake elevations and wetland areas are primarily supported by freshwater inputs from snowmelt feeding upgradient rivers, streams, and springs. These freshwater inputs have been severely reduced because of continued and increased surface-water diversions and surface-water capture through groundwater pumping for agriculture, mining, and public supply as well as unprecedented drought conditions and warming temperatures related to climate change. Water quality, specifically salinity, is highly variable for terminal lakes of the Great Basin, and this variability is a result of the balance between freshwater inflow and evaporation. Variability of salinity at each of the terminal lakes can be affected by lake morphology, hydrogeologic features of the basin, annual variability in weather patterns, and changes in upgradient water use. Hypersaline terminal lakes provide abundant food resources such as brine shrimp and brine flies that support nesting and migrating birds. The density and composition of invertebrates are closely tied to lake salinity. Increased salinity can exceed the tolerance of invertebrates, severely limiting their biomass. In contrast, decreased salinity can lead to altered invertebrate community composition, reducing the abundance of optimal avian prey resources. Great Basin terminal lake ecosystems, including open-water and adjacent aquatic and terrestrial environments, provide resources necessary to sustain many animal populations throughout the year. Although a variety of taxa use terminal lakes, these ecosystems are of acute importance for the millions of migratory waterbirds (for example, shorebirds, wading birds, and waterfowl) dependent on the network of terminal lakes and their associated wetlands. Migratory birds transiting the Pacific and Central Flyways use Great Basin terminal lake ecosystems throughout the year to feed, nest, and transit between wintering and breeding ranges. As such, successful conservation of birds and their habitats requires coordinated management of water and habitats across the Great Basin network of terminal lakes and wetlands. The linkages between water availability and ecosystem vulnerability of terminal lakes in the Great Basin are not well understood. The vulnerability of terminal lakes is related to the factors driving change and adaptive capacity of the lake ecosystem. Saline lake ecosystems are vulnerable when changes in water quantity affect ecosystem function. Water quantity affects salinity, which affects food webs and habitat; these linkages can be investigated with water-quality and food web monitoring. Water quantity also affects inundated habitat, which can be quantified through remote sensing. It is necessary to quantify hydroclimatic and water use controls on water availability to terminal lakes to assess the response of the ecosystems. Remotely sensed data can provide a broad-scale and long-term synoptic view of terminal lake hydrologic characteristics, but ground observations are required to interpret changes in water quality and ecological functions. Some terminal lake basins have ongoing monitoring and modeling efforts within the Great Basin (for example, Great Salt Lake, Carson River Basin), yet most monitoring locations are hydrologically upgradient and too far away from lake inflows to provide an accurate assessment of hydrological trends for the lake ecosystems. Other terminal lakes have no long-term hydrological monitoring in their respective watersheds (for example, Lake Abert). Ecological data collection in the Great Basin is also insufficient to understand how many birds exist on the landscape, how birds use the mosaic of terminal-lake habitats as an interconnected system, and how Great Basin terminal lakes are linked to the larger continental system of the Pacific and Central Flyways. Across agencies and organizations, tracking bird movement, abundance, and diversity is inconsistent, with some lakes having once- or twice-a-year bird survey efforts and a few locations having more intensive ecological data-gathering efforts (for example, Great Salt Lake, Lake Abert). Bridging hydrological and ecological information gaps will improve understanding of the trends in water supply and water quality, habitat availability and usage, and impacts on vulnerable waterbird species, all of which would be used by managers in coordinated conservation of this unique network of terminal-lake habitats. The terminal lakes of the Great Basin are part of the Basin and Range physiographic province that extends from the Colorado Plateau on the east to the Sierra Nevada on the west, and from the Snake River Plain on the north to the Garlock fault and the Mojave block on the south. The Great Basin is larger than 650,000 square kilometers and encompasses most of the State of Nevada but also extends to western Utah, eastern California, southeastern Idaho, southwestern Wyoming, and southeastern Oregon. The climate is arid to semiarid with a hydrologic regime that is snowmelt dominated, providing as much as 75 percent of total annual runoff for the region. Terminal lakes of the Great Basin occupy the lowest areas of closed (endorheic) drainage basins, such that lake levels and water quality respond rapidly to surface-water inflow. Terminal lakes provide local and regional economic value to the States in the Great Basin, including mineral extraction, aquaculture, public works, and recreational uses. As an example, assessments of Great Salt Lake’s ecological health and economic impact find hemispheric importance for the former and regional importance for the latter. Great Salt Lake creates about 7,000 jobs and $2 billion of economic output per year, most of which would be lost with further declines in lake level. The objectives of this Science Strategy are threefold: (1) to identify how changing water availability affects the quality, diversity, and abundance of habitats supporting continental waterbird populations; (2) to highlight the scientific monitoring and assessment needs of Great Basin terminal lakes; and (3) to support coordinated management and conservation actions to benefit those ecosystems, migratory birds, and other wildlife. There are long-term hydrological, ecological, and societal challenges associated with terminal lakes ecosystems in the Great Basin. This Science Strategy benefits partners by providing a conceptual model, nested at different spatial extents, that identifies key scientific information needs to inform coordinated implementation of management and conservation plans within and among hydrologic basins to address these complex challenges.

California, Idaho, Nevada, Oregon, Utah, Wyoming↗
USGS2007

Investigation of wind and water level for the Giacomini Wetland Restoration Project, Point Reyes National Seashore

Point Reyes National Seashore (PRNS), comprising unique elements of geological, biological, and historical interest, is located on the central California coast approximately 60 km northwest of San Francisco. The National Seashore contains nearly 130 km of exposed and protected shorelines, spectacular coastal cliffs and headlands, lagoons, open grasslands, bushy hillsides, and forested ridges. Approximately 30 km of the shoreline are coastal-dune habitat that supports 11 federally listed species, including the threatened western snowy plover and the endangered plants Tidestrom's lupine ( Lupinus tidestromii ) and beach layia ( Layia carnosa ). The San Andreas Fault, a right-lateral strike-slip fault, trends northwest along the northeastern side of the park. Tomales Bay, which is straight, long, narrow, and shallow, runs along the northeastern boundary of PRNS. The Bay, which fills the northwestern end of a rift valley at the intersection of the San Andreas Fault with the coastline, is approximately 20 km long, 2 km wide, and 6 m deep with mountainous terrain to the southwest and rolling hills to the northeast. Tomales Bay is one of the cleanest estuaries on the West Coast. In winter, approximately 17,000 to 20,000 shorebirds inhabit Tomales Bay and Bodega Bay, which lies directly to the north. At the head of Tomales Bay, the Giacomini Ranch comprises 563 acres of pastureland currently being used for grazing dairy cattle. After more than 50 years of operation as a dairy, the National Park Service acquired the Giacomini property with the intention to restore most of it and the nearby Olema Marsh to tidal wetland. Restoration will add approximately 4% to the existing coastal wetlands in California. The project will return the headwaters of Tomales Bay and two major stream intersections to an intertidal marsh environment, enhancing habitat for both wildlife and fish populations and contributing to the long-term health of Tomales Bay. Prior to the establishment of the ranch, the area was primarily salt marsh that formed as the delta of Lagunitas Creek expanded into Tomales Bay. In converting the salt marsh to dairy land, levees and tide gates were constructed to prevent tidal incursion and stream flooding. Those levees have significantly altered the patterns of estuarine circulation and sediment deposition. To restore natural hydrologic processes within the area and to promote the return of ecological functions and processes, the levees will have to be breached or removed. Developing a successful restoration strategy requires knowledge of elevations within the pastureland and the range of water depths that can be expected from tidal, river, and wind action. In support of the restoration program, the USGS provides technical assistance to PRNS in the form of a scientific study focusing on understanding the physical processes that could affect the Giacomini wetland restoration. The study will yield scientific products that NPS resource managers can use in designing and implementing the restoration project. Research elements include: - Develop a Geodetic Control Network (GCN) throughout PRNS that meets the standards specified National Geodetic Survey data base (the NGS "Bluebook"). The grid will allow this and future studies to be conducted to a precision commensurate with the expressed goals of PRNS. The survey will consist of three steps: (1) verify existing GPS control monuments in the area; (2) tie control monuments in the study areas to the GPS control monuments; and (3) establish NAVD88 elevations using a digital electronic level. - Conduct a detailed survey of the Giacomini site to produce an accurate topographic map of the property. The site survey can be coupled with on-site water-level measurements to produce an empirical flooding model. - Measure water level and wind regime at the Giacomini site. The water-level range is critical to determining the wetland types based on the elevation of the dairy land. Water level at Sacramento Landing, in central Tomales Bay, will also be measured for comparison. As of November 2005, we have created a GCN, produced a detailed topographic map of the Giacomini site, and collected approximately three years of water-level and wind data at the Giacomini site and over one year of usable water-level data at the Sacramento Landing pier.

California↗
USGS2018

Prioritization framework for ranking riverine ecosystem stressors using example sites from the Tualatin River Basin, Oregon

As human populations increase, so does their influence over the environment. Altered terrain, degraded water quality, and threatened or endangered species are all-too-common consequences of a growing anthropogenic influence on the landscape. To help manage these effects, researchers have developed new ways to characterize current environmental conditions and help resource managers seek solutions to bring affected areas back to their best attainable health. Before an ecosystem can be improved, however, its current level of ecological stress must be determined. Characterizing environmental conditions at many sites across a landscape helps managers understand the range of current conditions and prioritize where they might focus restoration and protection efforts. This report details the development of a prioritization framework to score riverine ecosystem stressors in a watershed based on example sites from the Tualatin River Basin in northwestern Oregon. The framework incorporated the most influential site-specific stressors throughout the basin built on a long history of data collection. These stressors were characterized with 13 metrics that were organized into 4 groups: hydrologic, water quality, physical habitat, and biological. Each stressor metric used readily accessible data and was translated to a score between 0 and 10. The higher the score, the healthier the site. This initial application of the framework used field observations and measurements to rank site conditions at two Tualatin River sites and four Tualatin River tributary sites. Given the versatility of this framework, it easily could be expanded to include more sites or new metrics, if necessary. Because stressors varied by season, all metrics for the tributary sites were scored separately during the wet season (November through April) and dry season (May through October). Water-quality data were available over a prolonged period; therefore, water-quality metrics were assessed by season and by decade (1990–99 compared to 2000–12) to evaluate long-term stressor trends. Results for the Tualatin River Basin prioritization framework indicated that the urban tributaries demonstrated the greatest stress throughout the year, especially during the dry summer months. Spatially, the upper Tualatin River was healthier than the lower reaches of the river. Water-quality has improved in the last 10 years, mostly due to improvements in the dry period contaminant scores, but challenges remain with high water temperatures and low dissolved-oxygen conditions. The biggest challenge with this type of research derived from inconsistencies within the available data. Both spatial and temporal data gaps must be addressed to improve the prioritization. Incorporating both discrete and continuous datasets into the prioritization framework remains a challenge because the datasets have slightly different information and criteria and are not always comparable. Regardless, this report provides guidelines for developing a prioritization framework that ranks the ecological health of sites in a watershed and provides guidance on management actions for improving conditions by targeting factors that greatly affect the health of river ecosystems.

Oregon↗
USGS2022

The mysterious case of the missing razor clams

Oceans are changing and these changes are affecting animals that live there. Animals respond differently to changes in water temperature, food availability, or contaminants. Those responses can be seen in their genes. Gene transcription is a tool that allows scientists to see the response of an animal’s genes to its environment. We used gene transcription to compare two populations of Pacific razor clams in Alaska: one that has lots of clams and one that used to have lots but doesn’t anymore. We were surprised when we didn't find any differences in their gene responses! So, we had to think about what else might be influencing the number of clams in these two populations. As we “dug” for answers, we found out that there are differences between the populations that don‘t influence their genes but may impact their numbers, such as predation.

Frontiers for Young Minds↗
USGS2019

Estimating connectivity of hard clam (Mercenaria mercenaria) and eastern oyster (Crassostrea virginica) larvae in Barnegat Bay

Many marine organisms have a well-known adult sessile stage. Unfortunately, our lack of knowledge regarding their larval transient stage hinders our understanding of their basic ecology and connectivity. Larvae can have swimming behavior that influences their transport within the marine environment. Understanding the larval stage provides insight into population connectivity that can help strategically identify areas for restoration. Current techniques for understanding the larval stage include modeling that combines particle attributes (e.g., larval behavior) with physical processes of water movement to contribute to our understanding of connectivity trends. This study builds on those methods by using a previously developed retention clock matrix (RCM) to illustrate time dependent connectivity of two species of shellfish between areas and over a range of larval durations. The RCM was previously used on physical parameters but we expand the concept by applying it to biology. A new metric, difference RCM (DRCM), is introduced to quantify changes in connectivity under different scenarios. Broad spatial trends were similar for all behavior types with a general south to north progression of particles. The DRCMs illustrate differences between neutral particles and those with behavior in northern regions where stratification was higher, indicating that larval behavior influenced transport. Based on these findings, particle behavior led to small differences (north to south movement) in transport patterns in areas with higher salinity gradients (the northern part of the system) compared to neutral particles. Overall, the dominant direction for particle movement was from south to north, which at times was enhanced by winds from the south. Clam and oyster restoration in the southern portion of Barnegat Bay could serve as a larval supply for populations in the north. These model results show that coupled hydrodynamic and particle tracking models have implications for fisheries management and restoration activities.

New Jersey↗
USGS2019

An introduced breeding population of Chrysemys picta marginata in the Kaibab National Forest, northern Arizona

The painted turtle ( Chrysemys picta ) is widely distributed from coast to coast in North America with each of four subspecies generally occupying different regions. In the southwestern USA and northern Mexico, where C. p. bellii is the expected native race, populations are small and widelyscattered. Introduced populations of other painted turtle subspecies are reported from various locations in the USA. We discovered a small but dense introduced population of C. p. marginata on the Colorado Plateau in northern Arizona, a region with few, if any, turtles due to aridity and an elevated topography with little surface water. The turtles were in a remote pond constructed to provide cattle with water. Chrysemys p. marginata occur naturally east of the Mississippi River, over 2,000 km away. The nearest native population of C. p. bellii in Arizona is over 160 km away. We observed nesting females, juveniles, and the presence of shelled eggs in females via Xradiography confirming a self-sustaining population. The body sizes and nesting season we observed were consistent with data for those variables from native populations of the taxon. It is unknown exactly how the turtles came to be established in such a remote location, but it is unlikely that they will spread due to the scarcity of perennial water sources in the semi-arid region. Due to increasing drought frequency and duration in the region, small populations like this one, introduced into a novel environment, may be bellwethers for monitoring the effects of climate change.

Arizona↗
USGS2018

Effects of climate change on ecological disturbance in the Northern Rockies Region [Chapter 8]

This chapter describes the ecology of important disturbance regimes in the Forest Service, U.S. Department of Agriculture (USFS) Northern Region and the Greater Yellowstone Area, hereafter called the Northern Rockies region, and potential shifts in these regimes as a consequence of observed and projected climate change. The term disturbance regime describes the general temporal and spatial characteristics of a disturbance agent - insect, disease, fire, weather, even human activity - and the effects of that agent on the landscape (table 8.1). More specifically, a disturbance regime is the cumulative effect of multiple disturbance events over space and time (Keane 2013). Disturbances disrupt an ecosystem, community, or population structure and change elements of the biological environment, physical environment, or both (White and Pickett 1985). The resulting shifting mosaic of diverse ecological patterns and structures in turn affects future patterns of disturbance, in a reciprocal, linked relationship that shapes the fundamental character of landscapes and ecosystems. Disturbance creates and maintains biological diversity in the form of shifting, heterogeneous mosaics of diverse communities and habitats across a landscape (McKinney and Drake 1998), and biodiversity is generally highest when disturbance is neither too rare nor too frequent on the landscape (Grime 1973).

General Technical Report↗
USGS2022

Management of diseases in free-ranging wildlife populations

Diseases are increasingly threatening the conservation of wildlife species. Spillover of pathogens into humans and domestic animals may negatively impact public health and the economy, requiring increased proactive management actions. The North American Wildlife Management Model provides the philosophical basis for managing wildlife and underpins all management options. Diseases in wildlife populations may be managed by manipulation of the environment, manipulation of the host, manipulation of the agent, and modification of human behavior. Important considerations include setting management goals, and metrics to assess success. Future strategies include using systems and One Health approaches to develop interventions that optimize outcomes for humans, animals, and the environment.

Book chapter↗
USGS2022

Applying consequence-driven scenario selection to lifelines

We present a new consequence-driven framework for earthquake scenario selection. For emergency managers, utility operators, policy makers, and other stakeholders, a scenario-based seismic risk assessment is often necessary for the purpose of emergency management and planning. In developing a scientifically defensible scenario, stakeholders can simulate a realistic event in order to pre-identify vulnerabilities in the system and support action to address these vulnerabilities. Selecting scenarios is particularly challenging for important population centers and critical infrastructure in stable tectonic environments, such as in the central and eastern United States, where uncertain long-term seismicity and unknown faults offer inadequate constraints. Notably, significant events in these so-called stable regions do occur (e.g., Nahanni, Canada, 1985, M6.9; Tennant Creek, Australia, 1998, M6.7). In regions of low seismicity, even moderate events can be consequential due to the higher vulnerability of buildings typical of such regions when compared to regions of higher seismicity. Furthermore, communicating seismic risk to stakeholders and the general public in these regions can be especially challenging due to the complexities of characterizing the hazard level. This framework has been developed to address these challenges for scenario selection in low seismic hazard regions. In this new approach, the analysis begins instead with the explicit definition of a consequence of concern to the specific stakeholder. This can range from a definition of loss (in lives, dollars, or another metric of interest), or a performance metric for critical infrastructure. The framework leverages United States Geological Survey software to run the hazard and consequence analysis. Driven by this stakeholder-defined consequence, an inversion analysis generates a complete event set of candidate scenarios that could breach this consequence. The final selection of a scenario, or family of scenarios, is then scientifically informed, but not limited by our lack of constraints in characterizing the hazard.

Conference Paper↗
USGS2021

Understanding genetics for successful conservation and restoration of resilient Chesapeake Bay brook trout populations

Traditionally, fisheries management has focused on the abundance, distribution, and size structure of populations. Although these factors remain key aspects of management, a large and growing body of evidence highlights the importance of genetics in conserving wild populations, especially when populations are small and isolated (Frankham et al. 2017). Local adaptations are very common among fishes and help populations cope with specific conditions in their local environment (Fraser et al. 2011). The field of conservation genetics and genomics is highly technical and has advanced rapidly in recent years, offering a wealth of information to support brook trout conservation and restoration. A major impediment to successfully incorporating these advances into conservation outcomes is that most fisheries managers have only a basic understanding of fish genetics and its relevance to their management decisions.

Maryland, Virginia↗
USGS1979

Conservation of marine birds of northern North America: Papers from the international symposium held at the Seattle Hyatt House, Seattle, Washington, 13-15 May 1975

The international symposium "Conservation of Marine Birds of Northern North America" was convened because of a growing awareness that not all was well with our marine birds. The symposium provided a forum for scientists, governmental administrators, conservationists, and laypeople to discuss the diverse topics and issues that we must all understand if we are to act both responsively and responsibly to assure that marine birds will not be lost through our neglect. The symposium was cosponsored by the Natural Resources Council of America, National Audubon Society, National Wildlife Federation, and the U.S. Department of the Interior, Fish and Wildlife Service; additional support was provided by the Canadian Wildlife Service, the International Association of Game, Fish, and Conservation Commissioners, the Pacific Seabird Group, the Sierra Club, the Smithsonian Institution, the Wildlife Management Institute, and the Wildlife Society. Persons interested and knowledgeable in the many and varied aspects of marine bird conservation were invited to participate in this symposium. There were 139 registered and several score of unregistered participants in attendance. Major topics treated were: (1) socioeconomic considerations and conservation of marine birds; (2) the marine environment of birds; (3) status of marine bird populations on land and sea; (4) the biology and ecology of marine birds in the North; (5) conflicts between the conservation of marine birds and uses of other resources; (6) programs and authorities related to the conservation of marine birds; and (7) conservation of marine birds in other lands.

Wildlife Research Report↗
USGS2004

Shifting shoals and shattered rocks: How man has transformed the floor of west-central San Francisco Bay

San Francisco Bay, one of the world's finest natural harbors and a major center for maritime trade, is referred to as the 'Gateway to the Pacific Rim.' The bay is an urbanized estuary that is considered by many to be the major estuary in the United States most modified by man's activities. The population around the estuary has grown rapidly since the 1850's and now exceeds 7 million people. The San Francisco Bay area's economy ranks as one of the largest in the world, larger even than that of many countries. More than 10 million tourists are estimated to visit the bay region each year. The bay area's population and associated development have increasingly changed the estuary and its environment. San Francisco Bay and the contiguous Sacramento-San Joaquin Delta encompass roughly 1,600 square miles (4,100 km2) and are the outlet of a major watershed that drains more than 40 percent of the land area of the State of California. This watershed provides drinking water for 20 million people (two thirds of the State's population) and irrigates 4.5 million acres of farmland and ranchland. During the past several decades, much has been done to clean up the environment and waters of San Francisco Bay. Conservationist groups have even bought many areas on the margins of the bay with the intention of restoring them to a condition more like the natural marshes they once were. However, many of the major manmade changes to the bay's environment occurred so long ago that the nature of them has been forgotten. In addition, many changes continue to occur today, such as the introduction of exotic species and the loss of commercial and sport fisheries because of declining fish populations. The economy and population of the nine counties that surround the bay continue to grow and put increasing pressure on the bay, both direct and indirect. Therefore, there are mixed signals for the future health and welfare of San Francisco Bay. The San Francisco Bay estuary consists of three subembayments--north bay (San Pablo and Suisun Bays), central bay, and south bay--each characterized by a central area of open water surrounded by intertidal mudflats and marshes. Central bay includes Alcatraz and Angel Islands and also a number of submerged bedrock knobs that protrude through the sediment of the bay floor and rise to within about 40 feet (12 m) of the water surface. The most prominent of these are Harding, Shag, Arch, and Blossom Rocks. These rocks have been lowered by blasting several times in the past, but they remain a potential hazard to shipping because newer cargo vessels are designed with increasingly deeper drafts. Central bay's location adjacent to two major population and commerce centers, San Francisco and Oakland, subjects it to greater human influences than less developed parts of the estuary. The western part of central San Francisco Bay is adjacent to the Golden Gate, the estuary's outlet to the Pacific Ocean. The changing submarine topography of the west-central bay, as well as its geology, form the main focus of this book.

California↗
USGS2001

Green fluorescent protein is lighting up fungal biology

Prasher ( 42 ) cloned a cDNA for the green fluorescent protein (GFP) gene from the jellyfish Aequorea victoria in 1992. Shortly thereafter, to the amazement of many investigators, this gene or derivatives thereof were successfully expressed and conferred fluorescence to bacteria and Caenorhabditis elegans cells in culture ( 10 , 31 ), followed by yeast ( 24 , 39 ), mammals ( 40 ), Drosophila ( 66 ), Dictyostelium ( 23 , 30 ), plants ( 28 , 49 ), and filamentous fungi ( 54 ). The tremendous success of GFP as a reporter can be attributed to unique qualities of this 238-amino-acid, 27-kDa protein which absorbs light at maxima of 395 and 475 nm and emits light at a maximum of 508 nm. The fluorescence of GFP requires only UV or blue light and oxygen, and therefore, unlike the case with other reporters (β-glucuronidase, β-galacturonidase, chloramphenicol acetyltransferase, and firefly luciferase) that rely on cofactors or substrates for activity, in vivo observation of gfp expression is possible with individual cells, with cell populations, or in whole organisms interacting with symbionts or environments in real time. Complications caused by destructive sampling, cell permeablization for substrates, or leakage of products do not occur. Furthermore, the GFP protein is extremely stable in vivo and has been fused to the C or N terminus of many cellular and extracellular proteins without a loss of activity, thereby permitting the tagging of proteins for gene regulation analysis, protein localization, or specific organelle labeling. The mature protein resists many proteases and is stable up to 65°C and at pH 5 to 11, in 1% sodium dodecyl sulfate or 6 M guanidinium chloride (reviewed in references 17 and 67 ), and in tissue fixed with formaldehyde, methanol, or glutaraldehyde. However, GFP loses fluorescence in methanol-acetic acid (3:1) and can be masked by autofluorescent aldehyde groups in tissue fixed with glutaraldehyde. Fluorescence is optimal at pH 7.2 to 8.0 ( 67 ). Limitations on GFP as a reporter for some applications are its low turnover rate, 2-h lag time for autoactivation of its chromophore, improper folding at high temperatures (37°C), which results in nonfluorescent and insoluble forms of the protein, and requirement for oxygen, which is not present in equal concentrations in all subcellular locations or cell types (reviewed in references 17 and 67 ). These characteristics of GFP, however, have not posed a problem for many applications, and mutant forms of GFP that have an ability to fold properly at high temperatures, increased solubility and fluorescence, reduced photobleaching ( 16 , 17 , 51 ), and reduced half-lives ( 1 ) have been developed. Coupled with fluorescence-activated cell sorting, confocal microscopy or quantitative image analysis techniques, GFP technology can be used to isolate transformed cells or specific cell types from populations of cells ( 14 ), to quantify gene expression of individual cells within whole organisms ( 8 ), or to assess the dispersal and biomass of organisms in complex environments, such as in animal or plant hosts ( 38 , 59 ), in biofilms ( 55 ), in fermentors ( 41 ), on leaf surfaces ( 53 , 61 ), or in soils ( 2 ). The vast majority of studies utilizing GFP expression in fungi have been with yeast (reviewed in reference 13 ). Ustilago maydis was the first filamentous fungus for which successful expression of gfp was reported ( 54 ), followed closely by Aspergillus nidulans ( 22 , 57 ) and Aureobasidium pullulans ( 61 ). Presently, gfp expression has been reported for 16 species comprising 12 genera of filamentous fungi, including Colletotrichum ( 21 , 44 ), Mycosphaerella ( 52 ), Magnaporthe ( 32 , 35 ), Cochliobolus ( 38 ), Trichoderma ( 2 , 70 ), Podospora ( 5 ), Sclerotinia ( 63 ), Schizophyllum ( 37 ), Aspergillus ( 20 , 47 , 50 ) and Phytophthora ( 7 , 62 ). In this review we draw on published reports, with the goal of providing an overview of GFP technology as it applies to the biology of filamentous fungi. These reports are not exhaustive of potential applications of GFP technology, as examples of genomic approaches to utilizing GFP in bacterial and yeast systems attest ( 4 , 46 , 60 , 65 ). Expression of gfp in filamentous fungi requires a gfp variant that is efficiently translated in fungi, a transformation system, and a fungal promoter that satisfies the requirements of a given experimental objective. Transformation of fungi has recently been reviewed by Gold et al. ( 26 ). Robinson and Sharon ( 44 ) suggest that GFP can actually be used to optimize transformation protocols. In addition to reporting the construction of a new fungal transformation vector that expresses SGFP under the control of the ToxA gene promoter from Pyrenophora tritici-repentis ( 12 ) and demonstrating its use in plant pathogens belonging to eight different genera of filamentous fungi ( Fusarium, Botrytis, Pyrenophora, Alternaria, Cochliobolus, Sclerotinia, Colletotrichum , and Verticillium ), in this review we also enumerate and describe a comprehensive list of vectors for expressing GFP in fungi.

Applied and Environmental Microbiology↗