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USGS2007

Coastal systems and low-lying areas

Since the IPCC Third Assessment Report (TAR), our understanding of the implications of climate change for coastal systems and low-lying areas (henceforth referred to as ‘coasts’) has increased substantially and six important policy-relevant messages have emerged. Coasts are experiencing the adverse consequences of hazards related to climate and sea level (very high confidence). Coasts are highly vulnerable to extreme events, such as storms, which impose substantial costs on coastal societies [6.2.1, 6.2.2, 6.5.2]. Annually, about 120 million people are exposed to tropical cyclone hazards, which killed 250,000 people from 1980 to 2000 [6.5.2]. Through the 20th century, global rise of sea level contributed to increased coastal inundation, erosion and ecosystem losses, but with considerable local and regional variation due to other factors [6.2.5, 6.4.1]. Late 20th century effects of rising temperature include loss of sea ice, thawing of permafrost and associated coastal retreat, and more frequent coral bleaching and mortality [6.2.5]. Coasts will be exposed to increasing risks, including coastal erosion, over coming decades due to climate change and sea-level rise (very high confidence). Anticipated climate-related changes include: an accelerated rise in sea level of up to 0.6 m or more by 2100; a further rise in sea surface temperatures by up to 3°C; an intensification of tropical and extra-tropical cyclones; larger extreme waves and storm surges; altered precipitation/run-off; and ocean acidification [6.3.2]. These phenomena will vary considerably at regional and local scales, but the impacts are virtually certain to be overwhelmingly negative [6.4, 6.5.3]. Corals are vulnerable to thermal stress and have low adaptive capacity. Increases in sea surface temperature of about 1 to 3°C are projected to result in more frequent coral bleaching events and widespread mortality, unless there is thermal adaptation or acclimatisation by corals [Box 6.1, 6.4]. Coastal wetland ecosystems, such as saltmarshes and mangroves, are especially threatened where they are sediment starved or constrained on their landward margin [6.4.1]. Degradation of coastal ecosystems, especially wetlands and coral reefs, has serious implications for the well-being of societies dependent on the coastal ecosystems for goods and services [6.4.2, 6.5.3]. ncreased flooding and the degradation of freshwater, fisheries and other resources could impact hundreds of millions of people, and socio-economic costs on coasts will escalate as a result of climate change [6.4.2, 6.5.3]. The impact of climate change on coasts is exacerbated by increasing human-induced pressures (very high confidence). Utilisation of the coast increased dramatically during the 20th century and this trend is virtually certain to continue through the 21st century. Under the SRES scenarios, the coastal population could grow from 1.2 billion people (in 1990) to 1.8 to 5.2 billion people by the 2080s, depending on assumptions about migration [6.3.1]. Increasing numbers of people and assets at risk at the coast are subject to additional stresses due to land-use and hydrological changes in catchments, including dams that reduce sediment supply to the coast [6.3.2]. Populated deltas (especially Asian megadeltas), low-lying coastal urban areas and atolls are key societal hotspots of coastal vulnerability, occurring where the stresses on natural systems coincide with low human adaptive capacity and high exposure [6.4.3]. Regionally, South, South- East and East Asia, Africa and small islands are most vulnerable [6.4.2]. Climate change therefore reinforces the desirability of managing coasts in an integrated manner [6.6.1.3]. Adaptation for the coasts of developing countries will be more challenging than for coasts of developed countries, due to constraints on adaptive capacity (high confidence). While physical exposure can significantly influence vulnerability for both human populations and natural systems, a lack of adaptive capacity is often the most important factor that creates a hotspot of human vulnerability. Adaptive capacity is largely dependent upon development status. Developing nations may have the political or societal will to protect or relocate people who live in low-lying coastal zones, but without the necessary financial and other resources/capacities, their vulnerability is much greater than that of a developed nation in an identical coastal setting. Vulnerability will also vary between developing countries, while developed countries are not insulated from the adverse consequences of extreme events [6.4.3, 6.5.2]. Adaptation costs for vulnerable coasts are much less than the costs of inaction (high confidence). Adaptation costs for climate change are much lower than damage costs without adaptation for most developed coasts, even considering only property losses and human deaths [6.6.2, 6.6.3]. As post-event impacts on coastal businesses, people, housing, public and private social institutions, natural resources, and the environment generally go unrecognised in disaster cost accounting, the full benefits of adaptation are even larger [6.5.2, 6.6.2]. Without adaptation, the high-end sea-level rise scenarios, combined with other climate changes (e.g., increased storm intensity), are as likely as not to render some islands and lowlying areas unviable by 2100, so effective adaptation is urgently required [6.6.3]. The unavoidability of sea-level rise, even in the longer-term, frequently conflicts with present-day human development patterns and trends (high confidence). Sea-level rise has substantial inertia and will continue beyond 2100 for many centuries. Irreversible breakdown of the West Antarctica and/or Greenland ice sheets, if triggered by rising temperatures, would make this long-term rise significantly larger, ultimately questioning the viability of many coastal settlements across the globe. The issue is reinforced by the increasing human use of the coastal zone. Settlement patterns also have substantial inertia, and this issue presents a challenge for long-term coastal spatial planning. Stabilisation of climate could reduce the risks of ice sheet breakdown, and reduce but Chapter 6 Coastal systems and low-lying areas 317 not stop sea-level rise due to thermal expansion [Box 6.6]. Hence, it is now more apparent than it was in the TAR that the most appropriate response to sea-level rise for coastal areas is a combination of adaptation to deal with the inevitable rise, and mitigation to limit the long-term rise to a manageable level [6.6.5, 6.7].

Book chapter↗

USGS2017

Water guns affect abundance and behavior of bigheaded carp and native fish differently

Water guns have shown the potential to repel nuisance aquatic organisms. This study examines the effects of exposure to a 1966.4 cm 3 seismic water gun array (two guns) on the abundance and behavior of Bighead Carp Hypophthalmichthys nobilis , Silver Carp H. molitrix (collectively referred to as bigheaded carp) and native fishes (e.g., Smallmouth Buffalo Ictiobus bubalus ). Water guns were deployed in a channel that connects the Illinois River to backwater quarry pits that contained a large transient population of bigheaded carp. To evaluate the effect of water guns, mobile side-looking split-beam hydroacoustic surveys were conducted before, during and between replicated water gun firing periods. Water guns did not affect abundance of bigheaded carp, but abundance of native fish detected during the firing treatment was 43 and 34% lower than the control and water guns off treatments, respectively. The proximity of bigheaded carp to the water gun array was similar between the water guns on and water guns off treatments. In contrast, the closest detected native fish were detected farther from the water guns during the water guns on treatment (mean ± SE, 32.38 ± 3.32 m) than during the water guns off treatment (15.04 ± 1.59 m). The water gun array had a greater impact on native fish species than on bigheaded carp. Caution should be taken to the extrapolation of these results to other fish species and to fish exposed to water guns in different environments (e.g., reduced shoreline interaction) or exposure to a larger array of water guns, or for use of water guns for purposes other than a barrier.

Illinois↗

USGS2024

Increased mercury concentrations in walleye and yellow perch in lakes invaded by zebra mussels

Zebra mussels ( Dreissena polymorpha ) are invasive species that alter ecosystems and food webs with the potential to affect aquatic mercury cycling and bioaccumulation in fishes, although the effect of zebra mussels on fish tissue mercury has not been tested in inland lakes. We assessed differences in fish tissue mercury concentrations and food webs in Minnesota lakes with and without zebra mussels while controlling for other lake and watershed characteristics. Mercury concentrations in adult walleye ( Sander vitreus ) and yellow perch ( Perca flavescens ) were 72 % and 157 % higher, respectively, in lakes containing zebra mussels compared to uninvaded lakes. Mercury in young of year (age-0) fish was also elevated, with mercury concentrations 97 % and 82 % higher in age-0 walleye and yellow perch, respectively, in zebra mussel lakes. Walleye mercury concentrations exceeded 0.22 ppm — a threshold triggering more restrictive human consumption advisories for sensitive populations — at a 23 % smaller size, and average-sized walleye (420 mm) exceeded this threshold at a rate of 77 % in invaded lakes, compared to 35 % in uninvaded lakes. Walleye and yellow perch relied more on littoral resources in lakes with zebra mussels but did not feed at meaningfully higher trophic levels. Increased fish tissue mercury in lakes invaded by zebra mussels have consequential implications for fisheries and human health.

Minnesota↗

USGS2004

The nearshore benthic invertebrate community of southern Lake Michigan and its response to beach nourishment

The nearshore benthic environment of Lake Michigan represents a dynamic and little studied habitat. To explore the biology and response of this community to beach nourishment, Ponar samples were taken at 1.5, 3, and 6 m depths at 10 transects along the southern shore of Lake Michigan before and after beach nourishment. Forty taxa were identified, and two of these, Chaetogaster diastrophus and Nematoda, made up over 81% of all organisms collected. Shallow sites (≤ 3 m) were generally dominated by C. diastrophus and Nematoda, and these sites represent communities adapted to constant wave induced sediment disturbance. Deep (6 m) sites were generally dominated by Nematoda, but fair numbers of C. diastrophus , Amphichaeta leydigi, Paracladopelma spp., and other less abundant taxa were identified. Greater diversity at deeper sites may be related to the stability resulting from reduced wave disturbance. A notable decrease in mean invertebrate density (P < 0.01) from 2001 to 2002 downdrift from the site of beach nourishment suggests that sand placement affected invertebrate populations, although a more thorough understanding of this community's response to environmental variables is required to further support this conclusion.

Journal of Great Lakes Research↗

USGS2002

Water-quality data analysis of the upper Gunnison River watershed, Colorado, 1989-99

Water-quality data from October 1969 to December 1999 for both surface water and ground water in the upper Gunnison River watershed were retrieved and compiled from the U.S. Geological Survey National Water Information System and the U.S. Environmental Protection Agency Storage and Retrieval databases. Analyses focused primarily on a subset of these data from October 1989 to December 1999. The upper Gunnison River watershed is located west of the Continental Divide in the Southern Rocky Mountains physiographic province. Surface-water-quality data were compiled for 482 sites in the upper Gunnison River watershed. Most values of surface-water temperature, dissolved oxygen, and pH were within Colorado Department of Public Health and Environment (CDPHE) in-stream standards. Calcium bicarbonate type water was the most spatially dominant water type in the basin. Nutrients were most commonly sampled along the Slate River and East River near Crested Butte and along the Gunnison River from the confluence of the East and Taylor Rivers to the western edge of the watershed. Median ammonia concentrations were low, with many concentrations less than laboratory reporting levels. All nitrate concentrations met the CDPHE in-stream standard of 10 milligrams per liter. More than 30 percent of stream sites with total phosphorus data (23 of 61 sites) had concentrations greater than the U.S. Environmental Protection Agency (USEPA) recommendation for controlling eutrophication. Ammonia concentrations at a site on the Slate River near Crested Butte had a statistically significant upward trend for the 1995–99 period. The Slate River near Crested Butte site is located immediately downstream from the towns of Crested Butte and Mount Crested Butte and may reflect recent population growth or other land-use changes. However, the rate of change of the trend is small (0.017 milligram per liter per year). Although a multiple comparison test showed nitrate concentrations were statistically different between agriculture and forest sites and between agriculture and urban land-use classified sites, median concentrations were low among all land-use settings. Median concentrations of total phosphorus were greatest in rangeland areas and least in urban areas. No significant differences were identified for median concentrations of total phosphorus in agriculture and forest land-use areas. Median concentrations of arsenic, lead, mercury, selenium, and silver were low or below reporting levels throughout the watershed. Aluminum, cadmium, copper, lead, manganese, and zinc concentrations were elevated near the town of Crested Butte and on Henson Creek upstream from Lake City, which may be explained by upstream areas of historical mining. Samples for six trace elements exceeded standards: cadmium, copper, lead, manganese, silver, and zinc. A downward trend (3 micrograms per liter per year) was identified for the dissolved iron concentration at a site on the Gunnison River at County Road 32 downstream from the city of Gunnison. Streambed-sediment samples from areas affected by historical mining also had elevated concentrations of some trace elements. Chlorophyll- a concentrations in samples from Blue Mesa Reservoir and streams in the Crested Butte and Gunnison areas were typical of unenriched to moderately enriched conditions. Median concentrations of 5-day biochemical oxygen demand concentrations for sites between Crested Butte and Blue Mesa Reservoir were less than 2 milligrams per liter. Occasional high (greater than 200 counts per 100 milliliters) concentrations for fecal coliform were determined at selected sites within the study area. However, median concentrations were less than 100 counts per 100 milliliters except for the Squaw Creek and Cimarron River areas in the western part of the watershed. Ground-water-quality data have been collected by the U.S. Geological Survey from 99 wells. Many wells were completed in aquifers composed of Holocene-age valley fill and alluvium. Most field properties were within the USEPA Secondary Drinking Water Regulations (SDWR) range for treated drinking water, except for 2 (of 40) pH samples. Calcium bicarbonate was the predominant water type in nearly all aquifers except for the aquifers composed of volcanic rock, which had more sodium and sulfate mixed water types. Wells with sulfate concentrations exceeding the SDWR of 250 milligrams per liter were completed in aquifers composed of volcanic rock near Lake City. Dissolution and oxidation of sulfide minerals in these aquifers may explain the elevated sulfate concentrations in ground water at these locations. Nutrient concentrations in ground water were generally low, and median concentrations for ammonia, nitrite, and dissolved phosphorus were below reporting levels. All nitrate concentrations in the samples were below the USEPA drinking-water maximum contaminant level of 10 mg/L. No statistical difference was found in nitrate concentrations among the four land-use classifications (agriculture, forest, rangeland, and urban). Trace elements in ground water were generally below the USEPA SDWR. Three iron samples exceeded the USEPA SDWR of 300 micrograms per liter at two wells located near the city of Gunnison and at a well south of the town of Powderhorn near the Cebolla River. Nine of 39 manganese samples exceeded the USEPA SDWR of 50 micrograms per liter and were collected from aquifers composed of Holocene-age valley fill and alluvium near Gunnison and Crested Butte and in one well near the Cebolla River. Radon gas is a natural radioactive decay product of uranium. All 39 radon samples collected from ground water in the watershed exceeded the proposed USEPA drinking-water maximum contaminant level of 300 picocuries per liter and ranged from 426 to 3,830 picocuries per liter.

Colorado↗

USGS2025

Sparse genetic data limit biodiversity assessments in protected areas globally

Global conservation targets include protecting genetic diversity within species. Yet few studies have assessed whether protected areas (PAs) include genetically diverse populations across species globally. A first step is understanding the availability of population genetic data that could be used in these assessments. We surveyed georeferenced population-level nuclear (as opposed to mitochondrial or plastid-based) genetic data across continents and marine biomes (36,354 populations, 2809 species) and found substantial geographic and taxonomic gaps. Most data were concentrated in Europe and North America, with major gaps in Africa and Asia. For most taxonomic groups, data were available for <1% of described species. Globally, 52.08% of the total areal extent of PAs lacked genetically sampled populations. These gaps in data availability highlight the need for targeted genetic data collection, harmonization, and sharing to improve genetic diversity monitoring and conservation planning. Combined with proxy-based genetic indicators, such data are needed to inform PA assessments, bolster area-based conservation initiatives like 30 × 30, and support achievement of global genetic conservation targets.

Frontiers in Ecology and the Environment↗

USGS2009

Forecasting urban growth across the United States-Mexico border

The sister-city area of Nogales, Arizona, and Nogales, Sonora, Mexico, is known collectively as Ambos (both) Nogales. This area was historically one city and was administratively divided by the Gadsden Purchase in 1853. These arid-lands have limited and sensitive natural resources. Environmental planning can support sustainable development to accommodate the predicted influx of population. The objective of this research is to quantify the amount of predicted urban growth for the Ambos Nogales watershed to support future planning for sustainable development. Two modeling regimes are explored. Our goal is to identify possible growth patterns associated with the twin-city area as a whole and with the two cities modeled as separate entities. We analyzed the cross-border watershed using regression analysis from satellite images from 1975, 1983, 1996, and 2002 and created urban area classifications. We used these classifications as input to the urban growth model, SLEUTH, to simulate likely patterns of development and define projected conversion probabilities. Model results indicate that the two cities are undergoing very different patterns of change and identify locations of expected growth based on historical development. Growth in Nogales, Arizona is stagnant while the urban area in Nogales, Sonora is exploding. This paper demonstrates an application that portrays how future binational urban growth could develop and affect the environment. This research also provides locations of potential growth for use in city planning.

Computers, Environment and Urban Systems↗

USGS2021

Zircon surface crystallization ages for the extremely reduced magmatic products of the Millennium Eruption, Changbaishan Volcano (China/North Korea)

The Millennium Eruption (ME) of Changbaishan volcano (Baitoushan, Paektu) at 946 CE (Common Era) is one of the largest explosive eruptions on Earth during Holocene times. We date unpolished zircon crystal faces from diverse ME products collected from the southern side of Changbaishan volcano where the ME pumice and welded and non-welded pyroclastic flow deposits (PFD) are better exposed. All zircons from a pumice sample of the southern caldera rim and the youngest (Group 1) zircons from a welded pumiceous PFD sample yield an isochron crystallization age of 0.7 ± 1.8 ka (2σ). Zircons from the welded pumiceous PFD sample yield additional two age groups at ~10 ka and ~ 100 ka. Zircons from a non-welded charcoal-containing PFD have only one age population at 100 ka. Our work shows that different eruption products from ME have different zircon surface age distributions and may tap different levels of a zoned felsic magma chamber. In addition, the results indicate that ion microprobe U-Th dating of zircon crystal surfaces from ME pumices can effectively date the Millennium eruption age. Previously reported zircon U-series ages for Qixangzhan eruption (12.2 ± 1.1 ka, 2σ) and Yuanchi eruption (7.3 ± 1.8 ka, 2σ) at Changbaishan are also likely to date their respective eruption ages. The occurrence of 100 ka zircons in welded and non-welded PFDs reveals an important magmatic event for the Changbaishan volcano. Zircon and Fe-rich clinopyroxene crystallized at similar temperature at 770–750 °C, indicative of early zircon crystallization in peralkaline magmas. Another important result is the extremely low oxygen fugacity (fO 2 = ΔFMQ-2) of the Changbaishan samples. Minerals in ME magmas were crystallized under some of the most reducing magmatic environments on Earth. Highly reducing conditions of magmas from Changbaishan supports a continental rift setting and argues against significant involvements of subduction-related oxidizing fluids during magma genesis.

Changbaishan Volcano↗

USGS2013

Genetic relationships among some subspecies of the Peregrine Falcon ( Falco peregrinus L.), inferred from mitochondrial DNA control-region sequences

The ability to successfully colonize and persist in diverse environments likely requires broad morphological and behavioral plasticity and adaptability, and this may partly explain why the Peregrine Falcon ( Falco peregrinus ) exhibits a large range of morphological characteristics across their global distribution. Regional and local differences within Peregrine Falcons were sufficiently variable that ∼75 subspecies have been described; many were subsumed, and currently 19 are generally recognized. We used sequence information from the control region of the mitochondrial genome to test for concordance between genetic structure and representatives of 12 current subspecies and from two areas where subspecies distributions overlap. Haplotypes were broadly shared among subspecies, and all geographic locales shared a widely distributed common haplotype (FalconCR2). Haplotypes were distributed in a star-like phylogeny, consistent with rapid expansion of a recently derived species, with observed genetic patterns congruent with incomplete lineage sorting and/or differential rates of evolution on morphology and neutral genetic characters. Hierarchical analyses of molecular variance did not uncover genetic partitioning at the continental level, despite strong population-level structure ( F ST = 0.228). Similar analyses found weak partitioning, albeit significant, among subspecies ( F CT = 0.138). All reconstructions placed the hierofalcons' (Gyrfalcon [ F. rusticolus ] and Saker Falcon [ F. cherrug ]) haplotypes in a well-supported clade either basal or unresolved with respect to the Peregrine Falcon. In addition, haplotypes representing Taita Falcon ( F. fasciinucha ) were placed within the Peregrine Falcon clade.

The Auk↗

USGS2011

A promising tool for subsurface permafrost mapping-An application of airborne geophysics from the Yukon River Basin, Alaska

Permafrost is a predominant physical feature of the Earth's Arctic and Subarctic clines and a major consideration encompassing ecosystem structure to infrastructure engineering and placement. Perennially frozen ground is estimated to cover about 85 percent of the state of Alaska where northern reaches are underlain with continuous permafrost and parts of interior Alaska are underlain by areas of discontinuous and (or) sporadic permafrost (fig. 1). The region of Interior Alaska, where permafrost is scattered among unfrozen ground, is a complex mosaic of terrains and habitats. Such diversity creates arrays of lakes and surface-water and groundwater patterns that continental populations of migratory waterfowl and internationally significant fisheries have adapted to over time. A road or pipeline might pass over frozen and unfrozen ground, affecting the types of materials and engineering approaches needed to sustain the infrastructure. Effective mapping of discontinuous permafrost at scales meaningful ecologically and (or) from an engineering perspective has been a long-standing challenge. Using techniques such as borehole logging for site-specific assessments or botanical techniques that can suggest underlying permafrost distributions can be labor intensive and difficult to accomplish at the scale and remoteness of much of Alaska. The climate is changing in the Arctic and Subarctic regions. The warming observed throughout much of Alaska could create widespread changes in permafrost. How the warming of the permafrost affects near-surface processes, ecosystems, and community infrastructure and ecosystems is not clear. A better understanding of the dynamic distribution and physical properties of permafrost, from continuous to discontinuous, will provide knowledge of how the permafrost environment may change in the future and help inform engineering and natural resource response strategies. Here we discuss an application of an airborne remote sensing methodology for mapping and shade imaging permafrost characteristics at various scales. This work provides the first look into three-dimensional distribution of permafrost in the areas around Fort Yukon and is a demonstration of the application of airborne electromagnetic (AEM) to permafrost mapping. Such an approach is attractive, particularly in Arctic and Subarctic studies, where ground access is difficult and ecosystems are fragile. In June 2010, the U.S. Geological Survey (USGS) conducted an AEM survey near Fort Yukon, Alaska. The primary focus of this survey was to map the distribution of permafrost in selected areas in order to supply information for the development of groundwater models of the Yukon River Basin. However, the methodologies have more far-reaching ecological and engineering applications. Approximately 1,800 line kilometers were acquired in a combination of typical block style surveying in the immediate area of Fort Yukon and in long reconnaissance lines over a broader area. The widely spaced lines were flown to cross the modern Yukon River in "X" like patterns with intersections at features that have been previously studied (fig. 2). AEM is used to gather data on the electrical resistivity of materials in the subsurface below the flight path of the helicopter, which are then analyzed to interpret the subsurface lithology and the location and extent of permafrost. For this survey, the electrical resistivity was imaged to depths on the order of 50-100 meters. Images from the survey can be qualitatively compared with known permafrost features and suggest new permafrost features. Electrical properties of earth materials are affected by lithology as well as temperature and the presence of ice; frozen materials become substantially more resistive. This allows for the identification of permafrost from the resistivity image (Abraham and others, 2011). In the area of Fort Yukon, the AEM survey shows elevated resistivities extending to depth, likely indicative of thick permafrost. This depth corresponds well to observations from a borehole drilled in the area in the late 1990s, which detected permafrost to a depth of about 100 meters (Clark and others, 2009). In contrast to the area of Fort Yukon, the Yukon River and its floodplain are not associated with deep resistive sediments, suggesting a lack of deep permafrost, at least within the depth range of the AEM mapping (fig. 3).

Yukon River Basin↗

USGS1989

Quantitative petrographic analysis of Desmoinesian sandstones from Oklahoma

Desmoinesian sandstones from the northern Oklahoma platform and the Anadarko, Arkoma, and Ardmore basins record a complex interaction between mid-Pennsylvanian source-area tectonism and cyclic sedimentation patterns associated with numerous transgressions and regressions. Framework-grain summaries for 50 thin sections from sandstones of the Krebs, Cabaniss, and Marmaton Groups and their surface and subsurface equivalents were subjected to multivariate statistical analyses to establish regional compositional trends for provenance analysis. R-mode cluster and correspondence analyses were used to determine the contributing effect (total variance) of key framework grains. Fragments of monocrystalline and polycrystalline quartz; potassium and plagioclase feldspar; chert; and metamorphic, limestone, and mudstone-sandstone rock fragments contribute most to the variation in the grain population. Q-mode cluster and correspondence analyses were used to identify four petrofacies and establish the range of compositional variation in Desmoinesian sandstones. Petrofacies I is rich in monocrystalline quartz (78-98%); mica and rock fragments are rare. Petrofacies II is also rich in monocrystalline quartz (60-84%) and averages 12% total rock fragments. Petrofacies III and IV are compositionally heterogeneous and contain variable percentages of monocrystalline and polycrystalline quartz, potassium feldspar, mica, chert, and metamorphic and sedimentary rock fragments. Quantitative analyses indicate that Desmoinesian sandstones were derived from sedimentary, igneous, and metamorphic source areas. Sandstones of petrofacies I and II occur mostly in the lower Desmoinesian and are widely distributed, although they are most abundant in eastern and central Oklahoma; sandstones of petrofacies III and IV are widely distributed and occur primarily in the middle and upper Desmoinesian. The range of compositional variation and the distribution of petrofacies are related to paleotectonics and basin development, sediment recycling, and varying depositional environments.

Oklahoma↗

USGS2010

Temporal and Spatial Distribution of Endangered Juvenile Lost River and Shortnose Suckers in Relation to Environmental Variables in Upper Klamath Lake, Oregon: 2008 Annual Data Summary

Lost River sucker (Deltistes luxatus) and shortnose sucker (Chasmistes brevirostris) were listed as endangered in 1988 for a variety of reasons including apparent recruitment failure. Upper Klamath Lake, Oregon, and its tributaries are considered the most critical remaining habitat for these two species. Age-0 suckers are often abundant in Upper Klamath Lake throughout the summer months, but catches decline dramatically between late August and early September each year and age-1 and older sub-adult suckers are rare. These rapid declines in catch rates and a lack of substantial recruitment into adult sucker populations in recent years suggests sucker populations experience high mortality between their first summer and first spawn. A lack of access to, or abundance of, optimal rearing habitat may exacerbate juvenile sucker mortality or restrict juvenile growth or development. Summer age-0 sucker habitat use and distribution has been studied extensively, but many uncertainties remain about age-1 and older juvenile habitat use, distribution, and movement patterns within Upper Klamath Lake. We designed a study to examine seasonal changes in distribution of age-1 suckers in Upper Klamath Lake as they relate to depth and water quality. In this document, which meets our annual data summary and reporting obligations, we discuss the results of our second annual spring and summer sampling effort. Catch data collected in 2007 and 2008 indicate seasonal changes in age-1 and older juvenile sucker habitat use coincident with changes in water quality, which were previously undocumented. In both years during April and May, age-1 and older juvenile suckers were found in shallow water environments. Then, as water temperatures began to warm throughout Upper Klamath Lake in June, age-1 and older juvenile suckers primarily were captured along the western shore in some of the deepest available environments. Following a dramatic decrease in dissolved oxygen concentrations in Eagle Ridge Trench, juvenile suckers were no longer found along the western shore but were captured throughout the rest of Upper Klamath Lake. When dissolved oxygen concentrations were 4 milligrams per liter or greater along the western shore, juvenile sucker captures were again concentrated in that area. Although this pattern indicates that low dissolved oxygen concentration or another related water-quality limitation may force juvenile suckers to leave the western shore, it is unclear as to why age-1 and older juveniles might be attracted to the area in the first place. Understanding this apparent behavior could be important to managing habitat for these species. In this data summary, we also describe the distribution of catches of age-0 suckers and other fishes in Upper Klamath Lake. These data corroborate previous studies that describe age-0 sucker habitat as shallow relative to depths available in Upper Klamath Lake. In this study, we did not seek, nor find additional clarification on age-0 sucker habitat use and distribution in Upper Klamath Lake. Our brief description of the distribution and abundance of all other fish species caught provides a context in which to assess the rarity of juvenile suckers within the fish community of Upper Klamath Lake.

Open-File Report↗

USGS2023

An assessment of the relation between metal contaminated sediment and freshwater mussel populations in the Big River, Missouri

The Big River in southeast Missouri drains the largest historical lead mining area in the United States. Ongoing releases of metal contaminated sediments into this river are well documented and are suspected of suppressing freshwater mussel populations. We characterized the spatial extent of metal contaminated sediments and evaluated its relationship with mussel populations in the Big River. Mussels and sediments were collected at 34 sites with potential metal effects and 3 reference sites. Analysis of sediment samples showed that lead (Pb) and zinc (Zn) concentrations were 1.5 to 65 times greater than background concentrations in the reach extending 168 km downstream from Pb mining releases. Mussel abundance decreased acutely downstream from these releases where sediment Pb concentrations were highest and increased gradually as Pb sediment concentrations attenuated downstream. We compared current species richness with historical survey data from three reference rivers with similar physical habitat characteristics and human effects, but without Pb-contaminated sediment. Big River species richness was on average about one-half that expected based on reference stream populations and was 70–75 % lower in reaches with high median Pb concentrations. Sediment Zn and cadmium, and particularly Pb, had significant negative correlations with species richness and abundance. The association of sediment Pb concentrations with mussel community metrics in otherwise high-quality habitat indicates that Pb toxicity is likely responsible for depressed mussel populations observed within the Big River. We used concentration-response regressions of mussel density verses sediment Pb to determine that the Big River mussel community is adversely affected when sediment Pb concentrations are above 166 ppm, the concentration associated with 50 % decreases in mussel density. Based on this assessment of metals concentrations sediment and mussel fauna, our findings indicate that sediment in approximately 140 km of the Big River with suitable habitat has a toxic effect to mussels.

Missouri↗

USGS2026

Evaluating treatment methods to control the egg masses of the crop pest Pomacea maculata

Pomacea maculata is an invasive aquatic apple snail species that poses serious ecological, agricultural, and public health threats across the southeastern United States. Its spread, particularly in Louisiana, has heavily impacted rice and crayfish farming, an industry producing over 90% of U.S. crayfish and valued at more than $250 million annually. The snail damages seedling rice, clogs crayfish traps, reduces yields, and increases labor for farmers. Moreover, it is a known host of rat lungworm ( Angiostrongylus cantonensis ), a parasite harmful to humans, making its presence in food production environments a public health concern. Controlling P. maculata is challenging due to its life cycle and reproductive strategies. The species lays large clutches of eggs above the waterline, where traditional aquatic molluscicides are ineffective. This study aimed to assess low-cost, practical methods for reducing egg hatch rates, specifically water submersion and vegetable oil application, on newly laid (day 1) and older (day 7) egg clutches. Laboratory trials on 125 egg clutches revealed that water submersion significantly reduced hatch rates and the development of dormant hatchlings, regardless of clutch age. Oil treatment only reduced hatch rates for day 1 clutches and had no effect on dormant hatchlings. These results suggest that water treatment is more broadly effective and feasible for farmers to apply without needing to determine egg age when applied on a routine, weekly basis. While oil showed limited use, its time-sensitive application limits practicality in the field. Water-based approaches offer a scalable solution for reducing P. maculata populations, but do not completely eliminate the potential for hatching and spreading. Without comprehensive control strategies targeting all life stages, the apple snail’s spread and associated impacts are expected to worsen, underscoring the urgency of continued management innovation.

Florida↗

USGS2006

The spatial and temporal trends of Cd, Cu, Hg, Pb and Zn in Seine River floodplain deposits (1994-2000)

Fresh floodplain deposits (FD), from 11 key stations, covering the Seine mainstem and its major tributaries (Yonne, Marne and Oise Rivers), were sampled from 1994 to 2000. Background levels for Cd, Cu, Hg, Pb, and Zn were established using prehistoric FD and actual bed sediments collected in small forested sub-basins in the most upstream part of the basin. Throughout the Seine River Basin, FD contain elevated concentrations of Cd, Cu, Hg, Pb and Zn compared to local background values (by factors > twofold). In the Seine River Basin, trace element concentrations display substantial downstream increases as a result of increasing population densities, particularly from Greater Paris (10 million inhabitants), and reach their maxima at the river mouth (Poses). These elevated levels make the Seine one of the most heavily impacted rivers in the world. On the other hand, floodplain-associated trace element levels have declined over the past 7 years. This mirrors results from contemporaneous suspended sediment surveys at the river mouth for the 1984-1999 period. Most of these temporal declines appear to reflect reductions in industrial and domestic solid wastes discharged from the main Parisian sewage plant (Seine Aval). ?? 2005 Elsevier B.V. All rights reserved.

Science of the Total Environment↗

USGS2014

Heterogeneous occupancy and density estimates of the pathogenic fungus Batrachochytrium dendrobatidis in waters of North America

Biodiversity losses are occurring worldwide due to a combination of stressors. For example, by one estimate, 40% of amphibian species are vulnerable to extinction, and disease is one threat to amphibian populations. The emerging infectious disease chytridiomycosis, caused by the aquatic fungus Batrachochytrium dendrobatidis ( Bd ), is a contributor to amphibian declines worldwide. Bd research has focused on the dynamics of the pathogen in its amphibian hosts, with little emphasis on investigating the dynamics of free-living Bd . Therefore, we investigated patterns of Bd occupancy and density in amphibian habitats using occupancy models, powerful tools for estimating site occupancy and detection probability. Occupancy models have been used to investigate diseases where the focus was on pathogen occurrence in the host. We applied occupancy models to investigate free-living Bd in North American surface waters to determine Bd seasonality, relationships between Bd site occupancy and habitat attributes, and probability of detection from water samples as a function of the number of samples, sample volume, and water quality. We also report on the temporal patterns of Bd density from a 4-year case study of a Bd -positive wetland. We provide evidence that Bd occurs in the environment year-round. Bd exhibited temporal and spatial heterogeneity in density, but did not exhibit seasonality in occupancy. Bd was detected in all months, typically at less than 100 zoospores L −1 . The highest density observed was ∼3 million zoospores L −1 . We detected Bd in 47% of sites sampled, but estimated that Bd occupied 61% of sites, highlighting the importance of accounting for imperfect detection. When Bd was present, there was a 95% chance of detecting it with four samples of 600 ml of water or five samples of 60 mL. Our findings provide important baseline information to advance the study of Bd disease ecology, and advance our understanding of amphibian exposure to free-living Bd in aquatic habitats over time.

California, Colorado, Idaho, Maine, Minnesota, Nev↗

USGS2025

Comparative life history of mud turtles (genus: Kinosternon) from the North American deserts

The warm deserts of North America are characterized by diverse environments that include the transition zone between tropical and temperate regions on the continent. This vast region includes the Sonoran and Chihuahuan deserts, which have different precipitation regimes and are composed of different floras and faunas, separated by the Cochise Filter Barrier. Inhabiting these deserts are 7 mud turtles (representing 4 separate clades within the genus Kinosternon ), and we compared their basic ecology, life history, and estivation time to test for variation between deserts. We used phylogenetic comparative methods to correlate the life history traits with environmental variables (temperature and precipitation) to test for variation between deserts. Life history strategies (clutch size, egg size, and reproductive phenology) of mud turtles were similar across both deserts, with negative correlations of clutch size and age of maturity with both aridity and temperature variables. Maximum estivation time was correlated with the seasonality of each included locality. Overall, life history strategies were quite similar, with small local specializations to avoid high temperatures and periodic lack of water. From a population ecology perspective, populations showed varied sex ratios biased toward males or females, along with different population structure among populations and species. However, most published studies lacked data for hatchlings. Phylogenetic signal is high in traits related to body size, including sexual size dimorphism. Overall, mud turtles from the southwest deserts are adapted to regional seasonality and precipitation regimes, with minor adjustments to fit local conditions.

Western North American Naturalist↗

USGS2019

Fire, forests and city water supply

Forest landscapes generate 57 percent of runoff worldwide and supply water to more than 4 billion people (Millennium Ecosystem Assessment, 2005). As the world population continues to increase, there is a strong need to understand how forest processes link together in a cascade to provide people with water services like hydropower, aquaculture, drinking water and flood protection (Carvalho-Santos, Honrado and Hein, 2014). Wildfire is a major disturbance affecting forested watersheds and the water they provide (Box 1) (Paton et al., 2015). Several regions have experienced shifts in wildfires from natural ignition sources (primarily lightning) to ignitions dominated by human activities, especially in areas where populations are increasing (Moritz et al., 2014; Balch et al., 2017). Occasional wildfire is essential for the health and functioning of fire-adapted ecosystems through its effects on nutrient cycling, plant diversity and succession, and pest regulation (Pausas and Keeley, 2019). It also reduces the risk of subsequent wildfires until a forest has accumulated sufficient fuels and conditions are conducive for another fire. Extreme and hazardous wildfires, on the other hand, can cause erosion, gullying, soil loss and flooding – and, in severe cases, even debris flows and flash floods – by removing the protective functions of forests on hillsides (Ebel and Moody, 2017). Extreme wildfires have become more common after decades of fire suppression, allowing forests to become much denser with vegetation and causing more fuels to build up over time. Combined with increasing summer drought, this can have impacts on water yield and the ability of upstream forests to deliver high-quality water because forest vegetation uses less water immediately after fire and, in environments influenced by snow, more snow can accumulate in forest clearings (Kinoshita and Hogue, 2015; Hallema et al., 2019). Therefore, accounting for wildfire impacts on forests in water planning has become a priority for the nexus of fire, water and society or, in other words, the connection between fire risk and water security (Figure 1) (Martin, 2016). In this article, we discuss managed forest landscapes as nature-based solutions for water and explore how fire affects the provision of water-related services.

Unasylva↗