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At least 91 records · Page 5Linked to original sources
USGS2018

Relationships between indicators of acid-base chemistry and fish assemblages in streams of the Great Smoky Mountains National Park

The acidity of many streams in the Great Smoky Mountains National Park (GRSM) has increased significantly since pre-industrial (∼1850) times due to the effects of highly acidic atmospheric deposition in poorly buffered watersheds. Extensive stream-monitoring programs since 1993 have shown that fish and macroinvertebrate assemblages have been adversely affected in many streams across the GRSM. Matching chemistry and fishery information collected from 389 surveys performed at 52 stream sites over a 22-year period were assessed using logistic regression analysis to help inform the U.S. Environmental Protection Agency’s assessment of the environmental impacts of emissions of oxides of nitrogen (NO x ) and sulfur (SO x ). Numerous logistic equations and associated curves were derived that defined the relations between acid neutralizing capacity (ANC) or pH and different levels of community richness, density, and biomass; and density and biomass of brook trout, rainbow trout, and small prey (minnow) populations in streams of the GRSM. The equations and curves describe the status of fish assemblages in the GRSM under contemporary emission levels and deposition loads of nitrogen (N) and sulfur (S) and provide a means to estimate how newly proposed (and various alternative) target deposition loads, which strongly influence stream ANC, might affect key ecological indicators. Several examples using ANC, community richness, and brook trout density are presented to illustrate the steps needed to predict how future changes in stream chemistry (resulting from different target deposition loads of N and S) will affect the probabilities of observing specific levels of selected biological indicators in GRSM streams. The implications of this study to the regulation of NO x and SO x emissions, water quality, and fisheries management in streams of the GRSM are discussed, but also qualified by the fact that specific examples provided need to be further explored before recommendations concerning their use as ecological indicators could be proposed.

North Carolina, Tennessee↗
USGS2008

Effects of methylmercury exposure on glutathione metabolism, oxidative stress, and chromosomal damage in captive-reared common loon (Gavia immer) chicks

We quantified the level of dietary mercury (Hg), delivered as methylmercury chloride (CH3HgCl), associated with negative effects on organ and plasma biochemistries related to glutathione (GSH) metabolism and oxidative stress, and chromosomal damage in captive-reared common loon (Gavia immer) chicks reared from hatch to 105 days. Mercury-associated effects related to oxidative stress and altered glutathione metabolism occurred at 1.2 :g Hg/g and 0.4 :g Hg/g, an ecologically relevant dietary mercury level, but not at 0.08 :g Hg/g. Among the variables that contributed most to dissimilarities in tissue chemistries between control and treatment groups were increased levels of oxidized glutathione (GSSG), GSH peroxidase, and the ratio of GSSG to GSH in brain tissue; increased levels of hepatic GSH; and decreased levels of hepatic glucose-6-phosphate dehydrogenase (G-6-PDH). Our results also suggest that chronic exposure to environmentally relevant dietary Hg levels did not result in statistically significant somatic chromosomal damage in common loon chicks. Oxidative stress and altered glutathione metabolism were evident in common loon chicks exposed to >0.4 :g Hg as CH3HgCl per gram wet food intake.

Environmental Pollution↗
USGS1990

Boron Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review

Ecological and toxicological aspects of boron (B) in the environment are reviewed, with emphasis on natural resources. Subtopics covered include environmental chemistry, background concentrations, effects, and current recommendations for the protection of living resources. Boron is not now considered essential in mammalian nutrition, although low dietary levels protect against fluorosis and bone demineralization. Excessive consumption (i.e., >1,000 mg B/kg diet, >15 mg B/kg body weight daily, >1.0 mg B/L drinking water, or >210 mg B/kg body weight in a single dose) adversely affects growth, survival, or reproduction in sensitive mammals. Boron and its compounds are potent teratogens when applied directly to the mammalian embryo, but there is no evidence of mutagenicity or carcinogenicity. Boron`s unique affinity for cancerous tissues has been exploited in neutron capture radiation therapy of malignant human brain tumors. Current boron criteria recommended for the protection of sensitive species include <0.3 mg B/L in crop irrigation waters, <1.0 mg B/L for aquatic life, <5.0 mg B/L in livestock drinking waters, <30 mg B/kg in waterfowl diets, and <100 mg B/kg in livestock diets.

Contaminant Hazard Reviews↗
USGS2022

Multi-year, spatially extensive, watershed-scale synoptic stream chemistry and water quality conditions for six permafrost-underlain Arctic watersheds

Repeated sampling of spatially distributed river chemistry can be used to assess the location, scale, and persistence of carbon and nutrient contributions to watershed exports. Here, we provide a comprehensive set of water chemistry measurements and ecohydrological metrics describing the biogeochemical conditions of permafrost-affected Arctic watersheds. These data were collected in watershed-wide synoptic campaigns in six stream networks across northern Alaska. Three watersheds are associated with the Arctic Long-Term Ecological Research site at Toolik Field Station (TFS), which were sampled seasonally each June and August from 2016 to 2018. Three watersheds were associated with the National Park Service (NPS) of Alaska and the U.S. Geological Survey (USGS) and were sampled annually from 2015 to 2019. Extensive water chemistry characterization included carbon species, dissolved nutrients, and major ions. The objective of the sampling designs and data acquisition was to characterize terrestrial–aquatic linkages and processing of material in stream networks. The data allow estimation of novel ecohydrological metrics that describe the dominant location, scale, and overall persistence of ecosystem processes in continuous permafrost. These metrics are (1) subcatchment leverage, (2) variance collapse, and (3) spatial persistence. Raw data are available at the National Park Service Integrated Resource Management Applications portal (O'Donnell et al., 2021, https://doi.org/10.5066/P9SBK2DZ ) and within the Environmental Data Initiative (Abbott, 2021, https://doi.org/10.6073/pasta/258a44fb9055163dd4dd4371b9dce945 ).

Alaska↗
USGS2012

Climate-change-driven deterioration of water quality in a mineralized watershed

A unique 30-year streamwater chemistry data set from a mineralized alpine watershed with naturally acidic, metal-rich water displays dissolved concentrations of Zn and other metals of ecological concern increasing by 100–400% (400–2000 μg/L) during low-flow months, when metal concentrations are highest. SO 4 and other major ions show similar increases. A lack of natural or anthropogenic land disturbances in the watershed during the study period suggests that climate change is the underlying cause. Local mean annual and mean summer air temperatures have increased at a rate of 0.2–1.2 °C/decade since the 1980s. Other climatic and hydrologic indices, including stream discharge during low-flow months, do not display statistically significant trends. Consideration of potential specific causal mechanisms driven by rising temperatures suggests that melting of permafrost and falling water tables (from decreased recharge) are probable explanations for the increasing concentrations. The prospect of future widespread increases in dissolved solutes from mineralized watersheds is concerning given likely negative impacts on downstream ecosystems and water resources, and complications created for the establishment of attainable remediation objectives at mine sites.

Environmental Science & Technology↗
USGS2012

The Cottonwood Lake study area, a long-term wetland ecosystem monitoring site

The Cottonwood Lake study area is one of only three long-term wetland ecosystem monitoring sites in the prairie pothole region of North America; the other two are Orchid Meadows in South Dakota and St. Denis in Saskatchewan. Of the three, Cottonwood Lake has, by far, the longest continuous data-collection record. Research was initiated at the study area in 1966, and intensive investigations of the hydrology, chemistry, and biology of prairie pothole wetlands continue at the site today. This fact sheet describes the study area, provides an overview of wetland ecology research that has been conducted at the site in the past, and provides an introduction to current work being conducted at the study area by USGS scientists.

North Dakota↗
USGS1986

Forested wetlands of the Southeast: Review of major characteristics and role in maintaining water quality

Forested wetlands occupying floodplains of major rivers in the Southeast are highly productive and diverse ecological systems. The wetlands are produced and maintained by fluvial processes and unique hydrologic regimes consisting of periodic flooding and subsequent drydown. Fluctuations in soil chemistry and biology resulting from this flooding and drydown provide a broad range of environmental conditions that are important in determining the role of forested wetlands in maintaining and improving water quality. The periodic shift between aerobic and anaerobic conditions in floodplain soils in response to flooding facilitates the assimilation of nutrients and organic matter, hastens the degradation of persistent pesticides, and decreases the bioavailability of heavy metals.

Resource Publication↗
USGS2014

Water-chemistry data collected in and near Kaloko-Honokohau National Historical Park, Hawaii, 2012–2014

Kaloko-Honokōhau National Historical Park (KAHO) on western Hawaiʻi was established in 1978 to preserve, interpret, and perpetuate traditional Native Hawaiian culture and activities, including the preservation of a variety of culturally and ecologically significant water resources that are vital to this mission. KAHO water bodies provide habitat for 1 threatened, 11 endangered, and 3 candidate threatened or endangered species. These habitats are sustained by, and in the case of ʻAimakapā Fishpond and the anchialine pools, entirely dependent on, groundwater from the Keauhou aquifer system. Development of inland impounded groundwater in the Keauhou aquifer system may affect the coastal freshwater-lens system on which KAHO depends, if the inland impounded-groundwater and coastal freshwater-lens systems are hydrologically connected. This report documents water-chemistry results from a U.S. Geological Survey study that collected and analyzed water samples from 2012 to 2014 from 25 sites in and near KAHO to investigate potential geochemical indicators in water that might indicate the presence or absence of a hydrologic connection between the inland impounded-groundwater and coastal freshwater-lens systems in the area. Samples were collected under high-tide and low-tide conditions for KAHO sites, and in dry-season and wet-season conditions for all sites. Samples were collected from two ocean sites, two fishponds, three anchialine pools, and three monitoring wells within KAHO. Two additional nearshore wells were sampled on property adjacent to and north of KAHO. Additional samples from the freshwater-lens system were collected from six inland wells located upslope from KAHO, including three production wells. Seven production wells in the inland impounded-groundwater system also were sampled. Water samples were analyzed for major ions, selected trace elements, rare-earth elements, strontium-isotope ratio, and stable isotopes of water. Precipitation samples from five sites were collected roughly along a transect upslope from KAHO. All precipitation samples were analyzed for stable isotopes of water and some precipitation samples were analyzed for rare-earth and selected trace elements.

Hawai'i↗
USGS2020

Cryptic lives of conspicuous animals: Otolith chemistry chronicles life histories of coastal lagoon fishes

Bar-built coastal lagoons are dynamic ecosystems at the land-sea interface that are important habitats for a variety of species. This study examined the habitat ecology of two lagoon species, the endangered Tidewater Goby ( Eucyclogobius newberryi ) and the Prickly Sculpin ( Cottus asper ) by reconstructing individual life histories from patterns in the concentration of the element Sr (as ratioed to Ca; Sr:Ca) in otoliths. Specific objectives were to (1) elucidate any movements of individual fishes among three primary habitat components of typical bar-built lagoon systems: coastal ocean, brackish lagoon, and freshwater watershed streams, and (2) determine if either species exhibited a consistent life history as defined by a stereotypical otolith Sr:Ca chronology, which could be indicative of a consistent range of salinity or temperature occupied through ontogeny. Results suggested that Tidewater Goby was a lagoon resident and that Prickly Sculpin exhibited migrations between lagoon and watershed stream habitats. There was no strong evidence in either species of ocean occupancy or of a stereotypical Sr:Ca chronology, the latter suggesting the full range of available lagoon habitat in terms of salinity and temperature was likely utilized at all life stages. These findings add to the body of evidence that bar-built lagoons are not isolated habitats, and holistic management of these habitats with adjoining watershed and marine environments could increase habitat connectivity across the landscape, with potential benefits to fishes.

California↗
USGS2007

Egg incubation position affects toxicity of air cell administered polychlorinated biphenyl 126 (3,3′,4,4′,5-pentachlorobiphenyl) in chicken (Gallus gallus) embryos

The avian egg is used extensively for chemical screening and determining the relative sensitivity of species to environmental contaminants (e.g., metals, pesticides, polyhalogenated compounds). The effect of egg incubation position on embryonic survival, pipping, and hatching success was examined following air cell administration of polychlorinated biphenyl (PCB) congener 126 (3,3',4,4',5-pentachlorobiphenyl [PCB 126]; 500-2,000 pg/g egg) on day 4 of development in fertile chicken ( Gallus gallus ) eggs. Depending on dose, toxicity was found to be up to nine times greater in vertically versus horizontally incubated eggs. This may be due to enhanced embryonic exposure to the injection bolus in vertically incubated eggs compared to more gradual uptake in horizontally incubated eggs. Following air cell administration of PCB 126, horizontal incubation of eggs may more closely approximate uptake and toxicity that has been observed with naturally incorporated contaminants. These data have implications for chemical screening and use of laboratory data for ecological risk assessments.

Environmental Toxicology and Chemistry↗
USGS2003

Ecological indicators of water quality in the Spokane River, Idaho and Washington, 1998 and 1999

A water-quality investigation of the Spokane River was completed during summer low-flow conditions in 1998 and 1999 as part of the USGS NAWQA Program, in cooperation with the WDOE. (Abbreviations used in this report are defined on the last page.) Samples for analyses of water chemistry; bed sediment; aquatic communities (fish, macroinvertebrates, and algae); contaminants in tissue (fish and macroinvertebrates); and associated measures of habitat were collected at six sites downstream from Coeur d’Alene Lake between river miles 63 and 100. These data provided baseline information to evaluate the water-quality status of the Spokane River and can be used to determine the ecological risk to aquatic organisms from contaminants.

Washington;Idaho↗
USGS2020

The transformative impact of genomics on sage-grouse conservation and management

For over two decades, genetic studies have been used to assist in the conservation and management of both Greater Sage-grouse ( Centrocercus urophasianus ) and Gunnison Sage-grouse ( C. minimus ), addressing a wide variety of topics including taxonomy, parentage, population connectivity, and demography. The field of conservation genetics has been transformed by dramatic improvements in sequencing technology, facilitating genomic studies in many wildlife species. The quality and amount of data generated by genomic methods vastly exceed that of traditional genetic studies, allowing for increased precision in estimating genetic parameters of interest. Perhaps more importantly, genomic methods can provide insight into non-neutral evolution such as adaptive divergence. Here we recount the shift from genetic to genomic methods using two wildlife species of substantial conservation interest, focusing on the improved capabilities and advantages of genomic methods. For instance, reassessment of divergence in sage-grouse using genomic methods confirmed strong differentiation between the two species and revealed that a small population in the state of Washington was more genetically distinct than previously recognized. Further, new genomic resources and approaches have been used to identify a family of genes linked to local dietary adaptation suggesting that sage-grouse may possess digestive and metabolic adaptations that mitigate the effects of consuming plant secondary metabolites like those found in sagebrush. Genetic variation among populations in these gene regions is thought to be involved with local dietary adaptations, and therefore maintaining the tie between sage-grouse and the chemistry of local sagebrush may be an important management consideration. We posit that the integration of newly developed genomic resources combined with the vast wealth of ecological and behavioral data for sage-grouse has the potential to shed light on mechanistic relationships that ultimately are vital to the conservation and management of these species.

Book chapter↗
USGS2024

Quantifying form resistance is essential for estimating summer low and bankfull flow from stream survey channel morphology

Reliable estimates of low flow and flood discharge at ungaged locations are required for evaluating stream flow alteration, designing culverts and stream crossings, and interpreting regional surveys of habitat and biotic condition. Very few stream gaging stations are located on small, remote streams, which typically have complex channel morphology. Adequate gaging is also lacking on larger streams that are remote, smaller than those typically gaged, or have channel morphology not conducive to installation of gages. Complex channels typically contain large scale hydraulic roughness elements that dominate flow patterns (i.e., form roughness), making it difficult to measure channel cross-section area and water velocity, or to measure channel volume even where discharge is known. In channels with large channel form roughness, it is equally difficult to estimate discharge using commonly applied equations based on slope and channel dimensions or basin area. We employed a novel approach that explicitly accounts for hydraulic resistance from large wood and riffle-pool morphology (form roughness) in calculating low flow and bankfull discharge from stream and river physical habitat data collected from 4229 stream and river sites in the conterminous US (CONUS) sampled in 2008–9 and 2013–14 as part of the US Environmental Protection Agency's N ational R ivers and S treams A ssessment (NRSA). Hydraulic resistance derived from form roughness clearly dominated resistance derived from bed particles (particle resistance) during summer low flows in wadeable streams across the spectrum of channel slopes and substrate sizes smaller than boulders. Under bankfull conditions, the influence of form resistance relative to particle resistance was diminished, but form resistance still dominated except in large low gradient rivers lacking complex channels, and in streams or rivers with boulder-size bed particles. We validated our hydraulic resistance estimates by comparing measured discharges with calculated discharges that used those hydraulic resistance estimates along with measured NRSA channel morphology data. Morphology-based summer discharge (low flow) estimates and direct field measurements of discharge in 2333 wadeable CONUS streams showed reasonable agreement (median difference < 2.5×) for discharges ranging from 3.6 × 10 −5 to 123 m 3 /s and drainage areas of 0.12 to 171,000 km 2 . In a subset of 759 of NRSA's larger wadeable stream and non-wadeable river sites where nearby U.S. Geological Survey (USGS) gage data were available and adequate, our morphology-based summer discharge estimates agreed fairly well (median difference < 2.0×) with USGS 20-yr average August mean flows ranging from 0.003 to 16,000 m 3 /s. Similarly, morphology-based estimates of bankfull flow ranging from 0.3 to 100,000 m 3 /s agreed reasonably well with the 1.5-yr recurrence interval flood in these gaged sites (median deviation <2.2×). These findings demonstrate the importance of quantifying flow resistance from large-scale form roughness features in natural channels and provide a novel approach for estimating discharge from widely available survey data. This will allow examination of discharge and its ecological influence across the full range of stream and river sizes sampled by NRSA or other synoptic surveys where comprehensive measures of biota, physical habitat, and chemistry are also made. Although these morphology-based estimates exhibit some variability, they are adequate for examining regional patterns in discharge and flow alteration and their association with instream biota and anthropogenic disturbances, providing summer low and bankfull flow information where reliable estimates are lacking.

Geomorphology↗
USGS2003

Quaternary vegetation and climate change in the western United States: Developments, perspectives, and prospects

This chapter explores the strengths and shortcomings of the major sources of data on Quaternary vegetation and climate change and discusses the use of models as a means to explore past and potential future environmental changes. The flora and major vegetation types of the western United States are present for several million years. Ongoing changes in atmospheric chemistry , climate, and human activities may lead to major vegetation changes over the coming decades to centuries. The combination of observations from the paleoenvironmental record, modern ecological studies, and modeling now permit assessments of the magnitude of potential future changes in the context of natural variability. They also provide opportunities for hypothesis testing and identification of the processes driving past changes in vegetation and climate. Understanding the dynamics of paleoenvironmental change can contribute to current conservation and natural resource management efforts and will help conservation and natural resource managers anticipate the potential rate, magnitude, and complexity of future vegetation change.

western United States↗
USGS2010

Breakpoint analysis and assessment of selected stressor variables on benthic macroinvertebrate and fish communities in Indiana streams: Implications for developing nutrient criteria

Water chemistry, periphyton and seston chlorophyll a (CHL a ), and biological community data were collected from 321 sites from 2001 through 2005 to (1) determine statistically and ecologically significant relations among the stressor (total nitrogen, total phosphorus, periphyton and seston CHL a , and turbidity) variables and response (biological community) variables; and, (2) determine the breakpoint of biological community attributes and metrics in response to changes in stressor variables. Because of the typically weak relations among the stressor and response variables, methods were developed to reduce the effects of non-nutrient biological stressors that could mask the effect of nutrients. Stressor variable concentrations ranged from 0.30 to 11.0 milligrams per liter (mg/L) for total nitrogen, 0.025 to 1.33 mg/L for total phosphorus, 2.9 to 768 milligrams per square meter (mg/m 2 ) for periphyton CHL a , and 0.37 to 42 micrograms per liter (µg/L) for seston CHL a . Turbidity, another stressor variable, ranged from 0.8 to 65.4 Nephelometric turbidity units (NTUs). When the nutrient and CHL a data were compared to Dodds’ trophic classifications, 75.0 percent of the values for total nitrogen, 46.6 percent of the values for total phosphorus, 35.8 percent of the values for periphyton CHL a , and 3.5 percent of the values for seston CHL a , were eutrophic. The invertebrate communities were dominated by families considered highly nutrient tolerant, Chironimidae, (41.7 percent relative abundance), Hydropsychidae, (17.3 percent relative abundance), and Baetidae, (10.2 percent relative abundance). Fish communities were dominated by algivores and nutrient-tolerant species, specifically central stonerollers (13.3 percent relative abundance), creek chubs (9.9 percent relative abundance), and bluntnose minnows (9.3 percent relative abundance). Although not the dominant taxa, white sucker, spotted sucker, green sunfish, and bluegill species were correlated (p ‹0.05) with the stressor variables. The median breakpoints ranged from 2.4 to 3.3 mg/L for total nitrogen, from 0.042 to 0.129 mg/L for total phosphorus, from 54 to 68 mg/m 2 for periphyton CHL a , from 4.5 to 7.5 µg/L for seston CHL a , and from 14.1 to 16.1 NTU for turbidity. The breakpoints determined in this study, in addition to Dodds’ trophic classifications, were used as multiple lines of evidence to show changes in fish and invertebrate community and attributes based on annual exposure to nutrients.

Indiana↗
USGS2015

River corridor science: Hydrologic exchange and ecological consequences from bedforms to basins

Previously regarded as the passive drains of watersheds, over the past 50 years, rivers have progressively been recognized as being actively connected with off-channel environments. These connections prolong physical storage and enhance reactive processing to alter water chemistry and downstream transport of materials and energy. Here we propose river corridor science as a concept that integrates downstream transport with lateral and vertical exchange across interfaces. Thus, the river corridor, rather than the wetted river channel itself, is an increasingly common unit of study. Main channel exchange with recirculating marginal waters, hyporheic exchange, bank storage, and overbank flow onto floodplains are all included under a broad continuum of interactions known as “hydrologic exchange flows.” Hydrologists, geomorphologists, geochemists, and aquatic and terrestrial ecologists are cooperating in studies that reveal the dynamic interactions among hydrologic exchange flows and consequences for water quality improvement, modulation of river metabolism, habitat provision for vegetation, fish, and wildlife, and other valued ecosystem services. The need for better integration of science and management is keenly felt, from testing effectiveness of stream restoration and riparian buffers all the way to reevaluating the definition of the waters of the United States to clarify the regulatory authority under the Clean Water Act. A major challenge for scientists is linking the small-scale physical drivers with their larger-scale fluvial and geomorphic context and ecological consequences. Although the fine scales of field and laboratory studies are best suited to identifying the fundamental physical and biological processes, that understanding must be successfully linked to cumulative effects at watershed to regional and continental scales.

Water Resources Research↗
USGS2011

Baseline ecological risk assessment of the Calcasieu Estuary, Louisiana: 3. An evaluation of the risks to benthic invertebrates associated with exposure to contaminated sediments

The sediments in the Calcasieu Estuary are contaminated with a wide variety of chemicals of potential concern (COPCs), including heavy metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, phthalates, chlorinated benzenes, and polychlorinated dibenzo-p-dioxins and dibenzofurans. The sources of these COPCs include both point and non-point source discharges. As part of a baseline ecological risk assessment, the risks to benthic invertebrates posed by exposure to sediment-associated COPCs were assessed using five lines of evidence, including whole-sediment chemistry, pore-water chemistry, whole-sediment toxicity, pore-water toxicity, and benthic invertebrate community structure. The results of this assessment indicated that exposure to whole sediments and/or pore water from the Calcasieu Estuary generally posed low risks to benthic invertebrate communities (i.e., risks were classified as low for 68% of the sampling locations investigated). However, incremental risks to benthic invertebrates (i.e., compared with those associated with exposure to conditions in reference areas) were indicated for 32% of the sampling locations within the estuary. Of the three areas of concern (AOCs) investigated, the risks to benthic invertebrates were highest in the Bayou d'Inde AOC; risks were generally lower in the Upper Calcasieu River AOC and Middle Calcasieu River AOC. The areas showing the highest risks to sediment-dwelling organisms were generally located in the vicinity of point source discharges of COPCs. These results provided risk managers with the information required to make decisions regarding the need for remedial actions at the site.

Louisiana↗