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USGS2026

Initial condition uncertainty exerts a large and persistent influence on model simulations of ecosystem carbon dynamics in California

Uncertainties in terrestrial ecosystem models limit their predictive power. Efforts to reduce projection error have rarely focused on constraining uncertainty in the initial state of the ecosystem, however, despite evidence that matching model initial conditions to real-world observations reduces overall model bias. Here we use an integrated land change and carbon gain-loss model to evaluate the influence of initial condition uncertainty on simulations of California wildland ecosystems during the years 1985–2020. We generated 36 initial conditions scenarios by varying the source data used to initialize state variables and then ran simulations based on each of these scenarios under a constant set of historical conditions. We found that discrepancies in initial forest extent and initial forest age among scenarios generated wide uncertainty ranges in model estimates of terrestrial ecosystem carbon stocks and flux rates at the outset of the simulation period, but differences in initial forest composition had no impact. Over time, forest age became more homogeneous across model scenarios leading to exponential rates of decline in the uncertainty ranges of live biomass and dead wood carbon but little to no impact on uncertainties in litter and soil organic carbon. Uncertainties in individual carbon flux rates were consistent with uncertainties in their source pools. In contrast, model estimates of ecosystem carbon balance demonstrated a shift in system behavior not apparent in trends for individual carbon stocks and fluxes. Specifically, estimates of ecosystem carbon balance converged across scenarios for the first 20 years of the simulation period but then began to diverge at an accelerating rate, possibly due to weakened resilience to the increased frequency and severity of climate-driven disturbances. Our results demonstrate that uncertainty in the initial state of the system can have large and persistent impacts on the predictability of ecosystem carbon dynamics, and that ongoing shifts in external forcing by climate and climate-driven disturbances can exacerbate these impacts.

California↗

USGS2013

Occurrence and variability of mining-related lead and zinc in the Spring River flood plain and tributary flood plains, Cherokee County, Kansas, 2009--11

Historical mining activity in the Tri-State Mining District (TSMD), located in parts of southeast Kansas, southwest Missouri, and northeast Oklahoma, has resulted in a substantial ongoing input of cadmium, lead, and zinc to the environment. To provide some of the information needed to support remediation efforts in the Cherokee County, Kansas, superfund site, a 4-year study was begun in 2009 by the U.S. Geological Survey that was requested and funded by the U.S. Environmental Protection Agency. A combination of surficial-soil sampling and coring was used to investigate the occurrence and variability of mining-related lead and zinc in the flood plains of the Spring River and several tributaries within the superfund site. Lead- and zinc-contaminated flood plains are a concern, in part, because they represent a long-term source of contamination to the fluvial environment. Lead and zinc contamination was assessed with reference to probable-effect concentrations (PECs), which represent the concentrations above which adverse aquatic biological effects are likely to occur. The general PECs for lead and zinc were 128 and 459 milligrams per kilogram, respectively. The TSMD-specific PECs for lead and zinc were 150 and 2,083 milligrams per kilogram, respectively. Typically, surficial soils in the Spring River flood plain had lead and zinc concentrations that were less than the general PECs. Lead and zinc concentrations in the surficial-soil samples were variable with distance downstream and with distance from the Spring River channel, and the largest lead and zinc concentrations usually were located near the channel. Lead and zinc concentrations larger than the general or TSMD-specific PECs, or both, were infrequent at depth in the Spring River flood plain. When present, such contamination typically was confined to the upper 2 feet of the core and frequently was confined to the upper 6 inches. Tributaries with few or no lead- and zinc-mined areas in the basin—Brush Creek, Cow Creek, and Shawnee Creek—generally had flood-plain lead and zinc concentrations (surficial soil, 6- and 12-inch depth) that were substantially less than the general PECs. Tributaries with extensive lead- and zinc-mined areas in the basin—Shoal Creek, Short Creek, Spring Branch, Tar Creek, Turkey Creek, and Willow Creek—had flood-plain lead concentrations (surficial soil, 6- and 12-inch depth) that frequently or typically exceeded the general and TSMD-specific PECs. Likewise, the tributaries with extensive lead- and zinc-mined areas in the basin had flood-plain zinc concentrations (surficial soil, 6- and 12-inch depth) that frequently or typically exceeded the general PEC. With the exception of Shoal and Willow Creeks, zinc concentrations typically exceeded the TSMD-specific PEC. The largest flood-plain lead and zinc concentrations (surficial soil, 6- and 12-inch depth) were measured for Short and Tar Creeks. Lead and zinc concentrations in the surficial-soil samples collected from the tributary flood plains varied longitudinally in relation to sources of mining-contaminated sediment in the basins. Lead and zinc concentrations also varied with distance from the channel; however, no consistent spatial trend was evident. For the surficial-soil samples collected from the Spring River flood plain and tributary flood plains, both the coarse (larger than 63 micrometers) and fine particles (less than 63 micrometers) contained substantial lead and zinc concentrations.

Kansas↗

USGS2006

Response of oxidative enzyme activities to nitrogen deposition affects soil concentrations of dissolved organic carbon

Recent evidence suggests that atmospheric nitrate (NO3- ) deposition can alter soil carbon (C) storage by directly affecting the activity of lignin-degrading soil fungi. In a laboratory experiment, we studied the direct influence of increasing soil NO 3- concentration on microbial C cycling in three different ecosystems: black oak-white oak (BOWO), sugar maple-red oak (SMRO), and sugar maple-basswood (SMBW). These ecosystems span a broad range of litter biochemistry and recalcitrance; the BOWO ecosystem contains the highest litter lignin content, SMRO had intermediate lignin content, and SMBW leaf litter has the lowest lignin content. We hypothesized that increasing soil solution NO 3- would reduce lignolytic activity in the BOWO ecosystem, due to a high abundance of white-rot fungi and lignin-rich leaf litter. Due to the low lignin content of litter in the SMBW, we further reasoned that the NO3- repression of lignolytic activity would be less dramatic due to a lower relative abundance of white-rot basidiomycetes; the response in the SMRO ecosystem should be intermediate. We increased soil solution NO3- concentrations in a 73-day laboratory incubation and measured microbial respiration and soil solution dissolved organic carbon (DOC) and phenolics concentrations. At the end of the incubation, we measured the activity of ??-glucosidase, N-acetyl-glucosaminidase, phenol oxidase, and peroxidase, which are extracellular enzymes involved with cellulose and lignin degradation. We quantified the fungal biomass, and we also used fungal ribosomal intergenic spacer analysis (RISA) to gain insight into fungal community composition. In the BOWO ecosystem, increasing NO 3- significantly decreased oxidative enzyme activities (-30% to -54%) and increased DOC (+32% upper limit) and phenolic (+77% upper limit) concentrations. In the SMRO ecosystem, we observed a significant decrease in phenol oxidase activity (-73% lower limit) and an increase in soluble phenolic concentrations (+57% upper limit) in response to increasing NO 3- in soil solution, but there was no significant change in DOC concentration. In contrast to these patterns, increasing soil solution NO3- in the SMBW soil resulted in significantly greater phenol oxidase activity (+700% upper limit) and a trend toward lower DOC production (-52% lower limit). Nitrate concentration had no effect on microbial respiration or ??-glucosidase or N-acetyl-glucosaminidase activities. Fungal abundance and basidiomycete diversity tended to be highest in the BOWO soil and lowest in the SMBW, but neither displayed a consistent response to NO 3- additions. Taken together, our results demonstrate that oxidative enzyme production by microbial communities responds directly to NO3- deposition, controlling extracellular enzyme activity and DOC flux. The regulation of oxidative enzymes by different microbial communities in response to NO3- deposition highlights the fact that the composition and function of soil microbial communities directly control ecosystem-level responses to environmental change. ?? 2006 Springer Science+Business Media, Inc.

Ecosystems↗

USGS2020

Lake trout rehabilitation in Lake Ontario, 2019

Each year we report on the progress toward rehabilitation of the Lake Ontario lake trout ( Salvelinus namaycush ) population, including the results of stocking, annual assessment surveys, creel surveys, and evidence of natural reproduction observed from all standard surveys performed by USGS and NYSDEC. The catch per unit effort of adult lake trout in gill nets increased each year from 2008-2014, recovering from historic lows recorded during 2005-2007. Adult abundances declined each year from 2015 to 2017; and in 2017 were about 35% below the 2014 peak and 17% below the 1999-2004 mean. Adult abundance increased in 2018 by 51% over the 2017 value and increased and addition 16% in 2019. The 2019 rate of wounding by sea lamprey (Petromyzon marinus) on lake trout caught in gill nets (0.53 A1 wounds (fresh wound) per 100 lake trout) was below target (2 wounds per 100 lake trout). Estimates from the NYSDEC fishing boat survey indicated angler catch rate of lake trout was low in 2019 and among the lowest recorded for the time series. Condition values for an adult lake trout, indexed in September from the predicted weight for a 700mm lake trout from annual length-weight regressions and Fulton’s K for age-6 males, were among the highest levels observed for the 1983-2019 time series. Predicted weight for a 400mm lake trout from July 2019 bottom trawl catches was near the long-term average while age-2 K was among the lowest for the time series. Reproductive potential for the adult stock indexed from the CPUE of mature females ≥ 4000g was again above the target in 2019 continuing a trend observed in nine of the last ten years. The 2019 catch of young native lake trout marked the 25th observation in the last 26 years, however the low numbers of native adults observed during that time period continues to indicate substantial restoration impediments still exist.

Lake Ontario↗

USGS1954

Sedimentary facies of iron-formation

The sedimentary iron -formations of Precambrian age in the Lake Superior region can be divided on the basis of the dominant original iron mineral into four principal facies : sulfide, carbonate, oxide, and silicate. As chemical sediments, these rocks reflect certain aspects of the chemistry of the depositional environments. The major control, at least for the sulfide, carbonate, and oxide types, probably was the oxidation potential. The evidence indicates that deposition took place in restricted basins, which were separated from the open sea by thresholds that inhibited free circulation and permitted development of abnormalities in oxidation potential and water composition. The sporadic distribution of metamorphism and of later oxidation permits description of the primary facies on the basis of unoxidized, essentially unmetamorphosed material. The sulfide facies is represented by black slates in which pyrite may make up as much as 40 percent of the rock. The free-carbon content of these rocks typically ranges from 5 to 15 percent, indicating that ultra-stagnant conditions prevailed during deposition. Locally, the pyritic rocks contain layers of iron -rich carbonate. The carbonate facies consists, in its purer form, of interbedded iron -rich carbonate and chert. It is a product of an environment in which oxygen concentration was sufficiently high to destroy most of the organic material but not high enough to permit formation of ferric compounds. The oxide facies is found as two principal types, one characterized by magnetite and the other by hematite. Both minerals appear to be of primary origin. The magnetite-banded rock is one of the dominant lithologies in the region; it consists typically of magnetite interlayered with chert, carbonate, or iron silicate, or combinations of the three. Its mineralogy and association suggest origin under weakly oxidizing to moderately reducing conditions, but the mode of precipitation of magnetite is not clearly understood. The hematite-banded rocks consist of finely crystalline hematite interlayered with chert or jasper. Oolitic structure is common. This facies doubtless accumulated in a strongly oxidizing, probably near-shore, environment similar to that in which younger hema-titic ironstones such as the Clinton oolite were deposited. The silicate facies contains one or more of the hydrous ferrous silicates (greenalite, minnesotaite, stilpnomelane, chlorite) as a major constituent. Granule structure, similar to that of glauconite, is typical of some varieties; others are nongranular and finely laminated. The most common association of the silicate rocks is with either carbonate- or magnetite-bearing rocks, which suggests that the optimum conditions for deposition ranged from slightly oxidizing to slightly reducing. The relationship between the iron -rich rocks and volcanism, stressed by many authors, is considered by the writer to be structural, not chemical: in the Lake Superior region both iron -deposition and volcanism are believed to be related to geosynclinal development during Huronian time. In Michigan, the lower Huronian rocks are iron -poor quartzite and dolomite-typical "stable-shelf" deposits; much of the upper Huronian consists of iron -poor graywacke and slate with associated volcanic rocks -a typical "geosynclinal" assemblage. Thus the iron -rich beds of the middle Huronian and lower part of the upper Huronian were deposited during a transitional stage in structural history. The major environmental requirement for deposition of iron - formation is the closed or restricted basin; this requirement coincides in time with what would be a normal stage in evolution of the geosyncline: namely, structural development of offshore buckles or swells that subsequently develop into island arcs characterized by volcanism.

Lake Superior↗

USGS2026

Restoring dryland water cycles for precipitation feedback and climate stability; a review

Drylands across the globe are experiencing intensifying water scarcity, land degradation, and hydroclimatic extremes. This review integrates evidence from multidecadal field studies, hydrologic monitoring, geomorphic and ecological assessments, remote sensing, and land–atmosphere science to evaluate how restoration influences key components of the terrestrial water cycle. Low-tech natural infrastructure in dryland streams (NIDS)—including check dams, leaky weirs, one-rock dams, and gabions—has emerged as a promising but under-synthesized nature-based solution for restoring hydrologic function in these environments. We describe the mechanisms through which these interventions modify runoff detention, infiltration, sediment and alluvial storage, shallow-groundwater recharge, vegetation recovery, and surface-energy partitioning, and we summarize outcomes across diverse dryland settings. Findings consistently show increased water residence time, enhanced soil-moisture storage, expanded riparian vegetation, extended flow duration, and shifts toward greater latent-heat flux—producing localized cooling and strengthened ecohydrological feedbacks. Building on these localized effects, we articulate a hypothesis that links the spatial extent of restoration, the density of NIDS per unit drainage area, and the magnitude of the latent-to-sensible-heat contrast generated by wetter post-rainfall conditions. Specifically, we hypothesize that when NIDS are implemented at densities permitted by topography and across areas large enough to maintain elevated soil moisture after storm events, the resulting increases in latent heat flux, surface cooling, and boundary-layer moistening may enhance moisture convergence and boundary-layer development, potentially increasing the likelihood or stability of convective precipitation, analogous to how reductions in these processes have contributed to regional drought intensification. These land–atmosphere feedbacks remain untested at scale but represent an important research Frontier. By integrating hydrologic, geomorphic, ecological, and atmospheric perspectives, this review provides a comprehensive framework for considering how low-tech, landscape-scale interventions can strengthen watershed resilience and contribute to climate-relevant nature-based solutions.

Arizona↗

USGS2005

Concentrations of cadmium, lead, and zinc in fish from mining-influenced waters of northeastern Oklahoma: Sampling of blood, carcass, and liver for aquatic biomonitoring

The Tri-States Mining District (TSMD) of Missouri (MO), Kansas (KS), and Oklahoma (OK), USA, was mined for lead (Pb) and zinc (Zn) for more than a century. Mining ceased more than 30 years ago, but wastes remain widely distributed in the region, and there is evidence of surface- and groundwater contamination in the Spring River-Neosho River (SR-NR) system of northeastern OK. In October 2001, we collected a total of 74 fish from six locations in the SR-NR system that included common carp (Cyprinus carpio), channel- and flathead catfish (Ictalurus punctatus and Pylodictis olivaris), largemouth- and spotted bass (Micropterus salmoides and Micropterus punctulatus), and white crappie (Pomoxis annularis). We obtained additional fish from locations in MO that included three reference sites and one site that served as a "positive control" (heavily contaminated by Pb). Blood, carcass (headed, eviscerated, and scaled) and liver (carp only) samples were analyzed for cadmium (Cd), Pb, and Zn. Our objectives were to assess the degree to which fish from the OK portion of the SR-NR system are contaminated by these elements and to evaluate fish blood sampling for biomonitoring. Concentrations of Cd and Pb in carp and catfish from OK sites were elevated and Pb concentrations of some approached those of the highly contaminated site in MO, but concentrations in bass and crappie were relatively low. For Zn, correlations were weak among concentrations in the three tissues and none of the samples appeared to reflect site contamination. Variability was high for Cd in all three tissues of carp; differences between sites were statistically significant (p < 0.05) only for blood even though mean liver concentrations were at least 100-fold greater than those in blood. Blood concentrations of Cd and Pb were positively correlated (r 2 = 0.49 to 0.84) with the concentration of the same element in carp and catfish carcasses or in carp livers, and the corresponding multiple regression models were highly significant (p < 0.001). Our data indicate that potentially nonlethal blood sampling can be useful for monitoring of selected metals in carp, catfish, and perhaps other fishes. ?? 2005 Springer Science+Business Media, Inc.

Archives of Environmental Contamination and Toxico↗

USGS2004

Environmental factors and chemical and microbiological water-quality constituents related to the presence of enteric viruses in ground water from small public water supplies in southeastern Michigan

A study of small public ground-water-supply wells that produce water from discontinuous sand and gravel aquifers was done from July 1999 through July 2001 in southeastern Michigan. Samples were collected to determine the occurrence of viral pathogens and microbiological indicators of fecal contamination (“indicators”), determine whether indicators are adequate predictors of the presence of enteric viruses, and determine the factors that affect the presence of enteric viruses. Small systems are those that serve less than 3,300 people. Samples were analyzed for specific enteric viruses by reverse transcriptase-polymerase chain reaction (RT-PCR), for culturable viruses by cell culture, and for the indicators total coliforms, Escherichia coli (E. coli) , enterococci, and F-specific and somatic coliphage. Ancillary environmental and water-quality data were collected or compiled. A total of 169 regular samples and 32 replicate pairs were collected from 38 wells. Replicate pairs were samples collected at the same well on the same date. One well was sampled 6 times, 30 wells were sampled five times, 6 wells were sampled twice, and 1 well was sampled once. By use of RT-PCR, enterovirus was found in four wells (10.5 percent) and hepatitis A virus (HAV) in five wells (13.2 percent). In two of these wells, investigators found both enterovirus and HAV, but on different sampling dates. Culturable viruses were found one time in two wells (5.9 percent), and neither of these wells was positive for viruses by use of RT-PCR on any sampling date. If results for all viruses are combined, 9 of the 38 small public-supply wells were positive for enteric viruses (23.7 percent) by either cell culture or RT-PCR. One or more indicators were found in 18 of 38 wells. Total coliforms, E. coli , enterococci, and F-specific and somatic coliphage were found in 34.2, 10.5, 15.8, 5.9, and 5.9 percent, respectively, of the wells tested. In only 3 out of 18 wells were samples positive for an indicator on more than one date at the same well. The co-occurrence of enteric viruses and any indicator was 55.6 percent; five out of the nine virus-positive wells were also found to be positive for an indicator. Two wells with detections of viruses had a detection of total coliforms, one well had a detection of E. coli , one of enterococci, and one of F-specific coliphage. On a per sample basis, of 11 samples that were positive for enteric viruses, indicator bacteria co-occurred in only 2 samples, and coliphage were not present in any. More virus-positive samples were found at sites served by septic systems than those served by sewerlines. Sampling condition (ground water or a mixture of tank and ground water), distance to septic system, type of and distance to nearest surface-water body, well characteristics, or land use were not related to the presence of viruses or indicators. Among continuous water-quality variables, statistically significant relations were found between total coliforms and dissolved organic carbon and between total coliforms and iron. There was a statistically significant relation between chloride concentrations >20 mg/L and detections of total coliforms. Presence of nitrate and nitrite was related to the presence of other indicators ( E. coli , enterococci, and F-specific and somatic coliphage) or enteric viruses, but not to total coliforms. The data indicated that chloride-to-bromide (C1:Br) ratios may be useful as a screening tool for total coliforms and enteric viruses but not for E. coli , enterococci, and F-specific and somatic coliphage. This study provides evidence for fecal contamination of ground water from small public-supply wells, at least on an intermittent basis. Collecting data on multiple lines of evidence would be needed to reliably predict the presence of enteric viruses and protect public health. Future data collection toward this end could include repeat sampling several times a year for different indicators, measuring dissolved-organic carbon, nitrate plus nitrite, and (or) chloride concentrations, or determining C1:Br ratios. The presence of a site served by a septic system is an indication that the well may be more vulnerable to contamination than a site served by a sewerline.

Michigan↗

USGS2008

Nutrient Loading and Algal Response in West Thompson Lake, Thompson, Connecticut, 2003-2005

Water quality and nutrient loads were characterized for parts of the Quinebaug River and West Thompson Lake in northeastern Connecticut during 2003 to 2005. The West Thompson Lake watershed is a mainly forested watershed that receives treated municipal wastewater from several point sources in Massachusetts. The lake is a flood-control reservoir formed in 1966 by impoundment of the Quinebaug River. Median concentrations of total phosphorus in two inflow (upstream) and one outflow (downstream) sampling stations on the Quinebaug River were higher than the nutrient criteria recommended by the U.S. Environmental Protection Agency (USEPA) for rivers and streams in aggregate Ecoregion XIV. In general, concentrations of total phosphorus in West Thompson Lake also were above the nutrient criteria recommended by USEPA for lakes and impoundments in aggregate Ecoregion XIV. The trophic status of West Thompson Lake has changed since 1995 from a hypereutrophic lake to a eutrophic lake; however, the lake still has large algal blooms. These blooms are predominated by blue-green algae, with chlorophyll-a concentrations of more than 30 micrograms per liter and algal cell counts as high as 73,000 cells/mL. Water samples collected during the summer of 2005 identified phosphorus as the primary limiting nutrient early in the season, but algal growth is probably co-limited by phosphorus and nitrogen later in the season. Lake-bottom sediments were collected from several areas throughout the lake and ranged in thickness from less than 1 foot (ft) to more than 3 ft. Concentrations of phosphorus in sediments differed throughout the lake; the highest values were found in the middle of the lake. Concentrations of total phosphorus also increased from an average 1,800 milligrams per kilogram (mg/kg) in the upper layers of sediment to more than 6,000 mg/kg at depth in the sediment. Annual, seasonal, and monthly loads and yields of nutrients were calculated for the three sampling locations on the Quinebaug River to develop a nutrient mass-balance model (budget) for West Thompson Lake. The average annual yields of total phosphorus during 2000 to 2005 were 115 pounds per square mile per year (lb/mi2/yr) at Quinebaug (inflow station), 116 lb/mi2/yr at Red Bridge Road (inflow station), and 97.9 lb/mi2/yr at West Thompson (outflow station). The 18-percent decrease in the average annual yield of total phosphorus between the inflow station at Red Bridge Road and the outlet of West Thompson Lake at West Thompson indicates that a significant part of the phosphorus load is retained in the lake. Annual yields of total phosphorus at Quinebaug have decreased significantly since the 1980s, from 362 lb/mi2/yr (for 1981-1990) to 115 lb/mi2/yr (1996-2005). The annual net export of phosphorus in West Thompson Lake during water years 2000 to 2005 ranged from -36 percent (2005) to 1 percent (2002) of the incoming load. Seasonal mass-balance data for total phosphorus during the summers of 2000 to 2003, when streamflow was at or lower than normal, indicated a net export of phosphorus that ranged from 3.4 percent (2003) to 30.7 percent (2002) of the incoming load. During the summer of 2004, however, streamflows were much higher than normal, and there was a negative export of phosphorus in West Thompson Lake of -3.9 percent. The annual net export of nitrogen in West Thompson Lake during water years 2000 to 2005 ranged from -5 percent (2002) to 4 percent (2001) of the incoming load. No clear pattern was evident to relate total nitrogen export to seasonal variables or runoff. Removal of phosphorus during the summer by wastewater-treatment plants (WWTPs) in Massachusetts reduces the concentration and load of total phosphorus entering West Thompson Lake in the summer; however, the large amount of phosphorus retained in the lake during the other seasons, in addition to the phosphorus stored in the lake-bottom sediments, may become available to fuel algal blooms in the lake

Scientific Investigations Report↗

USGS2014

Anthropogenic organic compounds in source water of select community water systems in the United States, 2002-10

Drinking water delivered by community water systems (CWSs) comes from one or both of two sources: surface water and groundwater. Source water is raw, untreated water used by CWSs and is usually treated before distribution to consumers. Beginning in 2002, the U.S. Geological Survey’s (USGS) National Water-Quality Assessment Program initiated Source Water-Quality Assessments (SWQAs) at select CWSs across the United States, primarily to characterize the occurrence of a large number of anthropogenic organic compounds that are predominantly unregulated by the U.S. Environmental Protection Agency. Source-water samples from CWSs were collected during 2002–10 from 20 surface-water sites (river intakes) and during 2002–09 from 448 groundwater sites (supply wells). River intakes were sampled approximately 16 times during a 1-year sampling period, and supply wells were sampled once. Samples were monitored for 265 anthropogenic organic compounds. An additional 3 herbicides and 16 herbicide degradates were monitored in samples collected from 8 river intakes and 118 supply wells in areas where these compounds likely have been used. Thirty-seven compounds have an established U.S. Environmental Protection Agency (EPA) Maximum Contaminant Level (MCL) for drinking water, 123 have USGS Health-Based Screening Levels (HBSLs), and 29 are included on the EPA Contaminant Candidate List 3. All compounds detected in source water were evaluated both with and without an assessment level and were grouped into 13 categories (hereafter termed as “use groups”) based on their primary use or source. The CWS sites were characterized in a national context using an extract of the EPA Safe Drinking Water Information System to develop spatially derived and system-specific ancillary data. Community water system information is contained in the EPA Public Supply Database, which includes 2,016 active river intakes and 112,099 active supply wells. Ancillary variables including population served, watershed size, land use, population density, and recharge were characterized for each of the watersheds for river intakes and contributing areas for supply wells. A total of 313 samples were collected from 20 river intakes. Between the years of 2002 through 2010, samples were collected approximately 16 times over the course of a year. Seventy-one compounds from 12 of the 13 use groups commonly occurred (detected in greater than or equal to 1 percent of samples using an assessment level of 0.05 microgram per liter or when a compound was detected in greater than or equal to 10 percent of samples without an assessment level) indicating a wide variety of sources and pathways to these rivers and highlighting the importance of source-water protection strategies. A total of 448 supply wells were sampled once during 2002–10 as part of 30 independent groundwater studies. About 15 CWS supply wells were sampled for each independent groundwater study. Twenty-eight compounds from 7 of the 13 use groups commonly occurred indicating a wide variety of sources and pathways exist for these compounds to reach these wells and highlighting the importance of wellhead protection strategies. About one-half the 265 compounds monitored (122) were detected in both surface water and groundwater samples. A more diverse suite of compounds were detected in surface water in comparison to groundwater. However, herbicides and herbicide degradates were the most frequent group of compounds detected in both surface water and groundwater. Sixty-five of the most commonly occurring compounds were detected in one or more samples from both surface water and groundwater. Human-health benchmarks (MCLs for regulated compounds and HBSLs for unregulated compounds) were available for more than one-half the compounds (160 of the 265) monitored in this study. Fifty-eight percent (41 of 71) of the commonly occurring compounds in surface water have a human-health benchmark to which concentrations can be compared; 19 have MCLs and 22 have HBSLs. Eighty-three percent (24 of 28) of the most commonly occurring compounds in groundwater have a human-health benchmark for which concentrations can be compared; 14 have MCLs and 10 have HBSLs. To put results from this study into context with the national distribution of river intakes and supply wells used by CWSs, sites were grouped into the respective national population of land-use quartiles. The increase in compound occurrence with increasing urban and agricultural land use in the watershed or contributing area was more evident for rivers than for supply wells. The increase in detection frequency of herbicides and herbicide degradates with increasing agricultural land use was more evident for rivers than for supply wells. The occurrence of solvents did not change substantially with increasing urban land use for rivers or supply wells. Basic co-occurrence analyses were completed with and without an assessment level. Considering all detections in surface water without an assessment level, approximately 86 percent of source-water samples contained 2 or more compounds, and 50 percent of samples contained at least 14 compounds. Considering all detections in groundwater without an assessment level, 50 percent of samples contained at least three compounds. For the most part, the compounds detected most frequently as individual compounds in the environment often composed the most frequent unique mixtures. Five of the 10 most frequently co-occurring unique mixtures in both surface water and groundwater were the same: atrazine and deethylatrazine; atrazine and chloroform; deethylatrazine and simazine; atrazine and simazine; and deethylatrazine, atrazine, and simazine. Because similar mixtures were identified in both surface water and groundwater without an assessment level, future studies could be directed toward better understanding the toxicological importance of these unique mixtures. Summed concentrations of herbicide degradates were compared to concentrations of the parent herbicides in surface-water and groundwater samples collected from 8 river intakes and 118 CWS wells, from which samples were analyzed for an additional 3 herbicides and 16 degradates. The toxicity to humans for many of these degradate products is largely unknown and thus points to the importance of monitoring these compounds (both the parent and degradate) in the environment. This study highlights the importance of anthropogenic organic compounds in source water of select CWSs in the United States by characterizing their occurrence in surface-water and groundwater samples. Compound concentrations and occurrence are summarized and evaluated in a human-health context, when possible. Additionally, compounds found to co-occur as mixtures for both surface water and groundwater highlight the significance of low-level compound co-occurrence.

Scientific Investigations Report↗

USGS1987

Results of a workshop concerning impacts of various activities on the functions of bottomland hardwoods

Under Section 404 of the Clean Water Act, the U.S. Environmental Protection Agency (EPA) has regulatory responsibilities related to the discharge of dredged or fill material into the Nation’s waters. In addition to its advisory role in the U.S. Army Corps of Engineers' permit program, EPA has a number of specific authorities, including formulation of the Section 404(b)(1) guidelines, use of Section 404(c) to prohibit disposal at particular sites, and enforcement actions for unauthorized discharges. A number of recent court cases focus on the geographic scope of Section 404 jurisdiction in potential bottomland hardwood (BLH) wetlands and the nature of landclearing activities in these areas that require a permit under Section 404. Accordingly, EPA needs to establish the scientific basis for implementing its responsibilities under Section 404 in bottomland hardwoods. EPA is approaching this task through a series of workshops designed to provide current scientific information on bottomland hardwoods and to organize that information in a manner pertinent to key policy questions. The first two workshops in the series were originally conceived as technically oriented meetings that would provide the information necessary to develop policy options at the third workshop. More specifically, the first workshop was designed to examine a zonation concept as a means of characterizing different BLH communities and describing variations in their functions along a soil moisture gradient. The second workshop was perceived as an attempt to evaluate the impacts of various activities on those functions. However, one conclusion of the first workshop, which was held in December 1984 in St. Francisville, Louisiana, was that the zonation approach does not describe the variability in the functions performed by BLH ecosystems sufficiently well to allow its use as the sole basis for developing a regulatory framework. That is, factors other than zone were considered critical for an effective characterization of the structure and functions of bottomland hardwoods. The approach to the second workshop, the results of which are described in this report, was therefore modified in response to the conclusions from the first workshop. The focus of the second workshop remained an analysis of the impacts of various activities or the functions of BLH ecosystems. However, as a prerequisite to this analysis, participants were also asked to develop a list of characteristics that determine the extent to which BLH sites perform the important functions. The workshop was organized such that alternating plenary and workgroup sessions allowed ample time for communication while still maintaining a focus on the overall goal. In the initial session, various individuals gave presentations concerning methodologies for evaluating the functions performed by wetlands, factors influencing the conversion of BLH forests to other uses, and the impacts of conversion activities. These were followed by a series of case study presentations designed to familiarize participants with the kinds of issues that are dealt with in the Section 404 program. These presentations are cited in this report as (author, workshop presentation). At the conclusion of these presentations, participants were divided into six workgroups to examine the functions of BLH ecosystems in the areas of hydrology, water quality, fisheries, wildlife, ecosystem processes, and culture/recreation/economics. Each workgroup was asked to undertake the following tasks. 1. Developed a list of functions performed by BLH ecosystems from the perspective of the workgroup's expertise and area of responsibility. 2. Identify those activities (e.g., impoundment construction, conversion to soybean farming) that impact the major functions (e.g., sediment retention, detrital export) performed by BLH ecosystems. 3. Develop a list of characteristics that determine the extent to which a BLH site performs each function and describe the relationship of each characteristic to the function. Develop, with supporting evidence where possible, an analysis of the impact of each activity (Task 2) on each characteristic (Task 3) and on each function as a whole. Upon completion of Task 2, in an effort to provide some uniformity in the analysis by the various workgroups, EPA personnel and several participants met and compiled a complete list of all the activities identified as having significant impacts in bottomland hardwoods (Table 1). From this list the group derived a set of seven activities, and a number of specific actions associated with each, for analysis by the workgroups (Table 2). These activities were selected on the basis of their perceived importance in BLH ecosystems and their interest from the perspective of EPA. Each workgroup was also encourage to ass any activities of particular important from its perspective. The workgroup reports that follow document the results of discussion concerning the above tasks. The WORKSHOP SUMMARY attempts to summarize these workgroup results, discuss availability of information, and identify some problems that must be addressed prior to the third workshop in this series.

Report↗

USGS2011

Effects of recreational flow releases on natural resources of the Indian and Hudson Rivers in the Central Adirondack Mountains, New York, 2004-06

The U.S. Geological Survey (USGS), the New York State Department of Environmental Conservation (NYSDEC), and Cornell University carried out a cooperative 2-year study from the fall of 2004 through the fall of 2006 to characterize the potential effects of recreational-flow releases from Lake Abanakee on natural resources in the Indian and Hudson Rivers. Researchers gathered baseline information on hydrology, temperature, habitat, nearshore wetlands, and macroinvertebrate and fish communities and assessed the behavior and thermoregulation of stocked brown trout in study reaches from both rivers and from a control river. The effects of recreational-flow releases (releases) were assessed by comparing data from affected reaches with data from the same reaches during nonrelease days, control reaches in a nearby run-of-the-river system (the Cedar River), and one reach in the Hudson River upstream from the confluence with the Indian River. A streamgage downstream from Lake Abanakee transmitted data by satellite from November 2004 to November 2006; these data were used as the basis for developing a rating curve that was used to estimate discharges for the study period. River habitat at most study reaches was delineated by using Global Positioning System and ArcMap software on a handheld computer, and wetlands were mapped by ground-based measurements of length, width, and areal density. River temperature in the Indian and Hudson Rivers was monitored continuously at eight sites during June through September of 2005 and 2006; temperature was mapped in 2005 by remote imaging made possible through collaboration with the Rochester Institute of Technology. Fish communities at all study reaches were surveyed and characterized through quantitative, nearshore electrofishing surveys. Macroinvertebrate communities in all study reaches were sampled using the traveling-kick method and characterized using standard indices. Radio telemetry was used to track the movement and persistence of stocked brown trout (implanted with temperature-sensitive transmitters) in the Indian and Hudson Rivers during the summer of 2005 and in all three rivers during the summer of 2006. The releases had little effect on river temperatures, but increased discharges by about one order of magnitude. Regardless of the releases, river temperatures at all study sites commonly exceeded the threshold known to be stressful to brown trout. At most sites, mean and median water temperatures on release days were not significantly different, or slightly lower, than water temperatures on nonrelease days. Most differences were very small and, thus, were probably not biologically meaningful. The releases generally increased the total surface area of fast-water habitat (rapids, runs, and riffles) and decreased the total surface area of slow-water habitat (pools, glides, backwater areas, and side channels). The total surface areas of wetlands bordering the Indian River were substantially smaller than the surface areas bordering the Cedar River; however, no channel geomorphology or watershed soil and topographic data were assessed to determine whether the releases or other factors were mainly responsible for observed differences. Results from surveys of resident biota indicate that the releases generally had a limited effect on fish and macroinvertebrate communities in the Indian River and had no effect on communities in the Hudson River. Compared to fish data from Cedar River control sites, the impoundment appeared to reduce total density, biomass, and richness in the Indian River at the first site downstream from Lake Abanakee, moderately reduce the indexes at the other two sites on the Indian River, and slightly reduce the indexes at the first Hudson River site downstream from the confluence with the Indian River. The densities of individual fish populations at all Indian River sites were also reduced, but related effects on fish populations in the Hudson River were less evident. Altho

Scientific Investigations Report↗

USGS2004

Chapter 4 The meade peak member of the phosphoria formation: Temporal and spatial variations in sediment geochemistry

Variations in the geochemistry of rocks from the Meade Peak Member of the Phosphoria Formation were examined using ratios of elements associated with either the +terrigenous or marine sediment fractions. Inter-element relationships in the terrigenous fraction appear useful for chemo-stratigraphic correlation. A sharp decrease upsection in K 2 O/AI 2 O 3 ratios occurs in the lower half of all but the most northeasterly section, wherein an offset is still evident in average and minimum values. These offsets correspond closely to the lower Guadalupian Series boundary as defined by conodont zonations, coincident with a change from major low-stand to transgressive conditions. The offsets are possibly the result of increased transport distances or flooding of source areas related to transgres- sion of the Phosphoria sea on the Wyoming shelf. A series of intervals displaying high Fe 2 O 3 /Al 2 O 3 , Ba/Al 2 O 3 and Sc/Al 2 O 3 ratios occur in the upper beds of the easternmost sections. The intervals do not appear to reflect amplified marine signals, but rather the introduction of terrigenous sediment from a secondary source, or, simply, reworking of sediments under higher energy conditions. The westernmost section, presumably repre- senting the deepest parts of the Phosphoria basin, contains intervals with high Ba/Al 2 O 3 . We suggest these horizons represent periods of low sediment accumulation during maxi- mum flooding and high-stand conditions. Inter-element relationships in the marine-derived sediment fraction indicate that bottom waters of the Phosphoria basin were dominantly denitrifying (suboxic). Ratios of Cd and Mo to Zn and Cu closely approach those in modern plankton in most of the sections, implying a major biogenic source for these elements. Exceptions occur through- out the westernmost (distal) section, possibly due to changes in the dominant plankton populations and relative nutrient uptakes, and in the upper part of the most northeasterly (shoreward, ramp) section, which we suggest is due to increased oxygen levels. Relatively thick phosphatic layers occur in basinal areas due largely to lack of terrig- enous dilution during deposition. These basinal deposits appear to have lower concentra- tions of many trace elements than more shoreward deposits. This may reflect deposition away from areas of peak primary production. Alternatively, biogenic detritus in these areas may have been derived from differing populations of primary producers with differing nutrient requirements. Both mid-shelf (middle ramp) and marginal environments were sites of accumulation of rich phosphatic units with high concentrations of trace elements. Deposits from marginal areas have the most varied geochemistry, largely because they experienced greater variability in terrigenous sediment influx. Even moderate changes in sea level may have dramatically altered energy levels, sediment mixing, and the amount of organic detritus reaching the sediment surface in these shallower marginal areas.

Colorado, Idaho, Montana, Nebraska, North Dakota, ↗

USGS2023

Hydrogeologic characterization of Area B, Fort Detrick, Maryland

Groundwater in the karst groundwater system at Area B of Fort Detrick in Frederick County, Maryland, is contaminated with chlorinated solvents from the past disposal of laboratory wastes. In cooperation with U.S. Army Environmental Command and U.S. Army Garrison Fort Detrick, the U.S. Geological Survey performed a 3-year study to refine the conceptual model of groundwater flow in and around Area B of Fort Detrick at the site- to regional-scale. The investigation was designed to review the geologic setting, assess the temporal variability of the hydrologic system, evaluate the potential for interbasin groundwater flow, determine the degree of vertical connectivity of the aquifer, characterize the sources and timing of groundwater recharge, and identify if dyes from previous tracer tests continue to drain from the aquifer. This study established a continuous hydrologic monitoring network of 12 water level gages, 2 streamgages, a precipitation gage, and in situ fluorometric monitoring. A water budget analysis was performed using hydrologic monitoring data and a soil-water balance model constructed for the study. In this study each individual water budget term is calculated using available data or through modeling, and a water budget residual term is calculated. If the water budget residual term is small relative to the uncertainty of the underlying data, then an additional import or export of water (in other words, interbasin transfer) is not needed to fully describe the hydrologic system. Groundwater and spring samples from 20 locations were collected in a 2019 synoptic geochemical sampling event and analyzed for a suite of analytes that included groundwater age tracer constituents. The karst groundwater system was found to be highly responsive to hydrologic events, with strong water level and stream base flow responses to individual storm events and a historic wet period in 2017 and 2018. The water budget analysis included historic flooding in May 2018, though more typical hydrologic patterns were observed in 2019 and 2020. During most evaluated intervals, the water budget residual was less than the estimated uncertainty on the residual for the two Carroll Creek watersheds, which suggested no substantial net interbasin flow occurs from these watersheds. The watershed difference area, a region that includes Area B, had a significant negative water budget residual, which may be the result of a net interbasin import of groundwater or the result of focused groundwater recharge not simulated by the soil-water balance model. Geochemical analysis and groundwater age dating reveals shallow groundwater (approximately less than [<] 150 feet deep) appears to be relatively young (approximately <30 years) and to be recharged in the vicinity of Area B. In the deep groundwater sampled in this study (approximately greater than [>] 150 feet deep), older groundwater from a differing recharge source, based on stable isotopes and noble gas analyses, is observed and interpreted to represent less direct connectivity to the surface and increased proportions of water recharged to the north and (or) west of Area B. A clustering analysis to reveal groupings within the suite of geochemical data was used to define seven groups. The groupings generally show that wells in similar depths and lateral aquifer positions generally cluster together, with some exceptions. Although limited by suspended sediments, the in situ fluorometric monitoring at springs did not detect any dye leaving the system above the limit of detection for the method. Dye was only detected above the limit of detection in one well, which was used as an injection well during a previous dye tracer test. The results of this study support and refine the conceptual site model of groundwater hydrology at Area B. The geologic and geophysical log review in this study agrees with prior assessments of physical controls on groundwater flow. A literature review of mid-Atlantic karst studies identified similar controls reported in these environments. The additional characterization of hydrologic responsiveness in this study suggests that hydrologic conditions and events are important considerations when interpreting potentiometric surfaces and contaminant trends over time and highlights the importance of continuous hydrologic monitoring. There is evidence to suggest that either intense focused groundwater recharge occurs in the vicinity of Area B or net along-valley groundwater interbasin flow from the upper study watershed enters the lower watershed and discharges to Carroll Creek. Geochemical analyses also suggest that water recharged from Catoctin Mountain and the elevated areas to the north and (or) west of the site may be present in the older and deeper Area B groundwater.

Maryland↗

USGS2000

Quality-assurance design applied to an assessment of agricultural pesticides in ground water from carbonate bedrock aquifers in the Great Valley of eastern Pennsylvania

Assessments to determine whether agricultural pesticides are present in ground water are performed by the Commonwealth of Pennsylvania under the aquifer monitoring provisions of the State Pesticides and Ground Water Strategy. Pennsylvania's Department of Agriculture conducts the monitoring and collects samples; the Department of Environmental Protection (PaDEP) Laboratory analyzes the samples to measure pesticide concentration. To evaluate the quality of the measurements of pesticide concentration for a groundwater assessment, a quality-assurance design was developed and applied to a selected assessment area in Pennsylvania. This report describes the quality-assurance design, describes how and where the design was applied, describes procedures used to collect and analyze samples and to evaluate the results, and summarizes the quality assurance results along with the assessment results. The design was applied in an agricultural area of the Delaware River Basin in Berks, Lebanon, Lehigh, and Northampton Counties to evaluate the bias and variability in laboratory results for pesticides. The design—with random spatial and temporal components—included four data-quality objectives for bias and variability. The spatial design was primary and represented an area comprising 30 sampling cells. A quality-assurance sampling frequency of 20 percent of cells was selected to ensure a sample number of five or more for analysis. Quality-control samples included blanks, spikes, and replicates of laboratory water and spikes, replicates, and 2-lab splits of groundwater. Two analytical laboratories, the PaDEP Laboratory and a U.S. Geological Survey Laboratory, were part of the design. Bias and variability were evaluated by use of data collected from October 1997 through January 1998 for alachlor, atrazine, cyanazine, metolachlor, simazine, pendimethalin, metribuzin, and chlorpyrifos. Results of analyses of field blanks indicate that collection, processing, transport, and laboratory analysis procedures did not contaminate the samples; there were no false-positive results. Pesticides were detected in water when pesticides were spiked into (added to) samples. There were no false negatives for the eight pesticides in all spiked samples. Negative bias was characteristic of analytical results for the eight pesticides, and bias was generally in excess of 10 percent from the ‘true’ or expected concentration (34 of 39 analyses, or 87 percent of the ground-water results) for pesticide concentrations ranging from 0.31 to 0.51 mg/L (micrograms per liter). The magnitude of the negative bias for the eight pesticides, with the exception of cyanazine, would result in reported concentrations commonly 75-80 percent of the expected concentration in the water sample. The bias for cyanazine was negative and within 10 percent of the expected concentration. A comparison of spiked pesticide-concentration recoveries in laboratory water and ground water indicated no effect of the ground-water matrix, and matrix interference was not a source of the negative bias. Results for the laboratory-water spikes submitted in triplicate showed large variability for recoveries of atrazine, cyanazine, and pendimethalin. The relative standard deviation (RSD) was used as a measure of method variability over the course of the study for laboratory waters at a concentration of 0.4 mg/L. An RSD of about 11 percent (or about ?0.05 mg/L)characterizes the method results for alachlor, chlorpyrifos, metolachlor, metribuzin, and simazine. Atrazine and pendimethalin have RSD values of about 17 and 23 percent, respectively. Cyanazine showed the largest RSD at nearly 51 percent. The pesticides with low variability in laboratory-water spikes also had low variability in ground water. The assessment results showed that atrazinewas the most commonly detected pesticide in ground water in the assessment area. Atrazine was detected in water from 22 of the 28 wells sampled, and recovery results for atrazine were some of the worst (largest negative bias). Concentrations of the eight pesticides in ground water from wells were generally less than 0.3 µg/L. Only six individual measurements of the concentrations in water from six of the wells were at or above 0.3 µg/L, ﬁve for atrazine and one for metolachlor. There were eight additional detections of metolachlor and simazine at concentrations less than 0.1 µg/L. No well water contained more than one pesticide at concentra-tions at or above 0.3 µg/L. Evidence exists, how-ever, for a pattern of co-occurrence of metolachlor and simazine at low concentrations with higher concentrations of atrazine. Large variability in replicate samples and negative bias for pesticide recovery from spiked samples indicate the need to use data for pesticide recovery in the interpretation of measured pesti-cide concentrations in ground water. Data from samples spiked with known amounts of pesticides were a critical component of a quality-assurance design for the monitoring component of the Pesti-cides and Ground Water Strategy. Trigger concentrations, the concentrations that require action under the Pesticides and Ground Water Strategy, should be considered maximums for action. This consideration is needed because of the magnitude of negative bias.

Water-Resources Investigations Report↗

USGS2011

Demographics and run timing of adult Lost River ( Deltistes luxatus ) and short nose ( Chasmistes brevirostris ) suckers in Upper Klamath Lake, Oregon, 2009

Data from a long-term capture-recapture program were used to assess the status and dynamics of populations of two long-lived, federally endangered catostomids in Upper Klamath Lake, Oregon. Lost River suckers ( Deltistes luxatus ) and shortnose suckers ( Chasmistes brevirostris ) have been captured and tagged with passive integrated transponder (PIT) tags during their spawning migrations in each year since 1995. In addition, beginning in 2005, individuals that had been previously PIT-tagged were reencountered on remote underwater antennas deployed throughout the spawning areas. Captures and remote encounters during spring 2009 were used to describe the spawning migrations in that year and also were incorporated into capture-recapture analyses of population dynamics over the last decade. Cormack-Jolly-Seber (CJS) open population capture-recapture models were used to estimate annual survival probabilities, and a reverse-time analog of the CJS model was used to estimate recruitment of new individuals into the spawning populations. In addition, data on the size composition of captured fish was examined for any additional evidence of recruitment. Survival and recruitment estimates were combined to estimate changes in population size over time and to determine the status of the populations through 2007. Separate analyses were conducted for each species and also for each subpopulation of Lost River suckers (LRS). One subpopulation of LRS migrates into tributaries to spawn, similar to shortnose suckers (SNS), whereas the other subpopulation spawns at upwelling areas along the eastern shoreline of the lake. In 2009, we captured and tagged 781 LRS at four shoreline areas and recaptured an additional 638 individuals that had been tagged in previous years. Across all four areas, the remote antennas detected 6,056 individual LRS during the spawning season. Spawning activity peaked in April and most individuals were encountered at Sucker Springs and Cinder Flats. In the Williamson River, we captured and tagged 3,008 LRS and 287 SNS, and recaptured 271 LRS and 81 SNS that had been tagged in previous years. Remote antennas that spanned the river downstream of the tributary spawning areas detected a total of 12,509 LRS and 5,023 SNS. Most LRS passed upstream in mid-April when water temperatures were rising and near or greater than 10°C. In contrast, peaks in upstream passage of SNS occurred in late April and early May when water temperatures were rising and near or greater than 12°C. Finally, an additional 1,569 LRS and 1,794 SNS were captured in trammel net sampling at prespawn staging areas in the northeastern portion of the lake. Of these, 209 of the LRS and 452 of the SNS had been PIT-tagged in previous years. For LRS, encounter histories showed that nearly all of the fish captured at the staging areas were members of the subpopulation that spawns in the tributaries. Capture-recapture analyses for the LRS subpopulation that spawns at the shoreline areas included encounter histories for more than 9,000 individuals, and analyses for the subpopulation that spawns in the tributaries included more than 14,000 encounter histories. With a few exceptions, the survival of males and females in both subpopulations was high (>0.9) between 1999 and 2007. Notably lower survival occurred for both sexes from the tributaries in 2000, for males from the shoreline areas in 2002, and for males from the tributaries in 2006. Recruitment of new individuals into either spawning population was trivial in all years between 2002 and 2007. Over that period, the abundance of males in the lakeshore spawning subpopulation declined by 44–53 percent and the abundance of females declined by 25–38 percent. Similarly, the abundance of males in the tributary spawning subpopulation declined by as much as 39 percent and the abundance of females declined by as much as 33 percent. Capture-recapture analyses for SNS included encounter histories for more than 12,000 individuals. The majority of annual survival estimates between 2001 and 2007 were high (>0.8), but SNS experienced more years of low survival than either LRS subpopulation. The survival of both sexes was particularly low in both 2001 and 2004, and male survival also was somewhat low in 2002 and 2006. Similar to LRS, recruitment of new individuals into the spawning population was trivial in all years between 2001 and 2007. Over that period, the abundance of male SNS declined by 58–80 percent and the abundance of females declined by 52–73 percent. Despite relatively high survival in most years, both species have experienced substantial declines in the abundance of spawning fish because losses from mortality have not been balanced by recruitment of new individuals. Indeed, all populations appear to be largely comprised of fish that were present in the late 1990s and early 2000s. As a result, the status of the endangered sucker populations in Upper Klamath Lake remains worrisome, and the situation is most dire for shortnose suckers. Survival analyses show that the two species do not necessarily experience poor survival in the same years and that poor survival on an annual scale is not predictable from fish die-offs observed in the summer and fall. Future analyses will explore the connections between annual sucker survival and environmental factors of interest, such as water quality and disease. Our monitoring program provides a robust platform for estimating vital population parameters, evaluating the status of the populations, and assessing the effectiveness of conservation and recovery efforts.

Oregon↗

USGS2022

Contaminants of emerging concern in the Great Lakes: Science to inform management practices for protecting the health and integrity of wildlife populations from adverse effects: GLRI action plan I, focus area 1, goal 5

Executive Summary: Under Action Plan I (2010-2014) of the Great Lakes Restoration Initiative (GLRI), Federal and Academic partners began an investigation of the presence and distribution of contaminants of emerging concern (CECs) in the Great Lakes and potential impacts on fish and wildlife. The term CECs is applied to a broad range of chemicals that are currently in use but for which we currently lack good understanding of whether fish, wildlife, or humans are being exposed and/or whether negative health or environmental effects are expected if exposure occurs. Pharmaceuticals, personal care products, flame retardants, many current use pesticides, and poly- and perfluorinated chemicals are some well-known groups of CECs, but there is no definitive or comprehensive list that can be used to support the management of CECs to reduce impacts on the Great Lakes ecosystem. Four overarching goals were identified for this collaborative investigation: 1. Evaluate the sources, occurrence, and distribution of CECs across the Great Lakes Basin. 2. Examine associations between the distribution of CECs and land-use patterns. 3. Review both scientific literature and field-generated data to determine the potential for CECs to cause adverse effects on Great Lakes fish and wildlife populations. 4. Develop efficient strategies to survey and/or monitor for threats that CECs may pose in order to take effective management actions before those threats evolve into large scale impacts on Great Lakes ecosystems or the services they provide. Achievement of these goals ensures progress towards Focus Area 1: Toxic Substances and Areas of Concern from GLRI Action Plan I, Goal 5: “ The health and integrity of wildlife populations and habitat are protected from adverse chemical and biological effects associated with the presence of toxic substances in the Great Lakes Basin ”. This large-scale research effort was comprised of individual and collaborative projects from multiple federal agencies and academic institutions, involving over 85 investigators, and overseen by the U.S. Environmental Protection Agency (EPA) Region 5, Great Lakes National Program Office. Partners include the United States Geological Survey, the National Oceanic and Atmospheric Administration, U.S. Fish and Wildlife Service, Saint Cloud State University, the U.S. EPA Office of Research and Development, and the U.S. Army Corps of Engineers. Key findings: 1. Contaminants of emerging concern were found throughout the monitored Great Lakes tributaries, but types and concentrations vary in association with regional land use. CECs were detected in nearly all samples collected. The type and concentration of the specific contaminants detected varied considerably among field sites and in association with land use type, such as urban, agricultural, wetland, 2 or forest. Contaminants were detected in the water column, sediment, and tissues of all species surveyed in the current work (mussels, aquatic insects, fish, and insect-eating birds). 2. There were over 20 contaminants for which CEC concentrations approached or exceeded those reported to cause toxicity in laboratory experiments. This was based on detection in water, sediments and or biota at one or more field sites. These contaminants represent compounds that warrant further investigation and monitoring with respect to potential impacts in certain areas of the Great Lakes basin. Based on the present investigation, compounds of greatest concern include: polycyclic aromatic hydrocarbons, associated with oil-based products and combustion of organic matter; atrazine, an herbicide; dichlorvos, an insecticide; and ibuprofen and venlafaxine, both pharmaceuticals. 3. Results suggest that mixtures of CECs presently found in most Great Lakes tributary locations surveyed may elicit subtle biological effects, but likely are not, alone, causing obvious detriment to current communities of fish and wildlife. CECs detected in the Great Lakes were associated with subtle biological effects like changes in gene expression, altered circulating glucose, etc. in both wild-caught and laboratory-reared organisms. These effects were generally not indicative of reproductive failure or mortality. However, the effects may have more serious implications when combined with other sources of stress like habitat degradation, changing climate conditions, and competition with invasive species. Due to limited historical data, it is unknown whether severe CEC-related impacts have already affected aquatic communities in waterbodies that have received long-term inputs of these contaminants. Likewise, under Action Plan I, biological effects were not necessarily evaluated at the sites where CEC concentrations exceeding laboratory toxicity thresholds were detected. As a result, strategic, ongoing surveillance and monitoring of CECs is warranted. This collaborative investigation resulted in new tools, approaches, and data that can be used to inform and support the management of CECs to reduce their impacts on Great Lakes natural resources. The following products of this research effort are available through https://communities.geoplatform.gov/glri/ or by contacting the investigators (see technical chapters found in Appendices A-F): 1. Database of CEC occurrence and concentrations in US tributary streams. The database includes CEC detections in water, sediment, and fish and wildlife tissues, and represents the most comprehensive survey of CECs in the Great Lakes Region. 2. Synopses of results and key findings. Integrated summaries of results, conclusions, and management implications of the CEC research are available through reports, topical fact sheets, and presentations. 3. Technical publications: This collaborative research effort has resulted in over 50 peer-reviewed publications, agency reports, and data releases that can be of use to resource managers, the scientific community, and members of the public. 4. Innovative tools. Innovative monitoring devices, sampling equipment, conceptual frameworks, and software applications were developed over the course of this 3 research. These tools are transferable to stakeholders via internet accessibility or via specifications, instructions, and demonstration detailed in technical publications. Hypotheses to guide CECs research under Action Plan II. Findings from 2010-2014 were used to guide further research in 2015-2018 for basin-wide surveillance of CECs and for sites warranting further study of potential biological impacts of CECs. Additional surveillance included both evaluation of additional classes of contaminants and expanded lists for chemical classes shown to be of greatest concern. Mixtures of some of the most frequently detected contaminants were also tested in laboratory studies to understand whether long term exposures to multiple contaminants may result in effects not evident from uncontrolled, short-term field experiments.

Great Lakes↗

USGS2014

Population viability and connectivity of the Louisiana black bear ( Ursus americanus luteolus )

In 1992, the U.S. Fish and Wildlife Service (USFWS) granted Ursus americanus luteolus (Louisiana black bear) threatened status under the U.S. Endangered Species Act of 1973, listing loss and fragmentation of habitat as the primary threats. A study was developed by the U.S. Geological Survey in cooperation with the University of Tennessee, the Louisiana Department of Wildlife and Fisheries, and the USFWS to estimate demographic rates and genetic structure of Louisiana black bear populations; evaluate relations between environmental and anthropogenic factors and demographic, genetic, and movement characteristics of Louisiana black bear populations; and develop data-driven stochastic population projection models to assess long-term persistence of individual subpopulations and the overall black bear population in Louisiana. Data were collected with non-invasive DNA sampling, live capture, winter den visits, and radio monitoring from 2002 to 2012 in the four areas supporting breeding subpopulations in Louisiana: Tensas River Basin (TRB), Upper Atchafalaya River Basin (UARB), Lower Atchafalaya River Basin (LARB), and Three Rivers Complex (TRC). Bears were live trapped and radio collared in the TRB and TRC to estimate survival and reproductive rates, deterministic matrix models were used to estimate asymptotic growth rates, and stochastic population models were used to estimate long-term viability. DNA extracted from hair collected at baited, barbed-wire enclosures in the TRB, UARB, and LARB and capture-mark-recapture (CMR) analysis based on Bayesian hierarchical modeling methods were used to estimate apparent survival ( φ ), per capita recruitment ( γ ), abundance ( N ), realized growth rate ( λ ), and long-term viability. From 2002 to 2012, we radio monitored 86 adult females greater than (>) 2 years old within the TRB, and 43 adult females were monitored in the TRC. The mean annual survival rate estimate ranged from 0.97 to 0.99 for the TRB and from 0.93 to 0.97 for the TRC. Fecundity and yearling recruitment in the TRB were 0.47 and 0.15, respectively, whereas estimates for the TRC were 0.37 and 0.18. Depending on estimated carrying capacity, the strength of the density dependence, level of uncertainty, and the treatment of unresolved signals, persistence probabilities for the TRC subpopulation ranged from 0.295 to 0.999. Estimates of N for females in the TRB ranged from 140 to 163 during 2006–12 when detection heterogeneity was assumed to follow a logistic-normal distribution (Model 1) and from 133 to 158 when a 2-point finite mixture distribution was assumed (Model 2). Annual estimates of γ ranged from 0.00 to 0.16 and from 0 to 0.22, depending on the model, and estimates of φ ranged from 0.87 to 0.93 during that period. In the UARB, estimates of N for females ranged from 25 to 44 during the study period, regardless of heterogeneity model. Estimated γ ranged from 0.00 to 0.41, and φ ranged from 0.88 to 0.90 during that period. Estimated N for females in the LARB was from 78 to 97 from 2010 to 2012 based on Model 1 and from 68 to 84 based on Model 2. Estimates of γ were 0.00 for 2010–11 regardless of heterogeneity model and ranged from 0.24 to 0.31 for 2011–12, depending on the model assumptions. We estimated φ as 0.81 for 2010–11, and from 0.84 to 0.85 for 2011–12, depending on model assumptions. We estimated Φ as 0.81 for 2010–11, ranging and from 0.84 to 0.85 for 2011–12, depending on model assumptions. On the basis of vital rate estimates from Model 1 of the CMR analysis, probability of persistence over 100 years for the TRB population was >0.999, 0.975, and 0.958 for process-only, 50-percent (%) credible interval (CI), and 95% CI projections, respectively. Similarly, the probability of persistence based on Model 2 was >0.999, 0.982, and 0.958. For the UARB, probabilities of persistence based on Model 1 were >0.999, 0.971, and 0.958 for process-only, 50% CI, and 95% CI projections, respectively, and 0.993, 0.929, and 0.849 for Model 2. Using the telemetry and reproductive data from the TRC, probabilities of persistence were greater than or equal to 0.95 only for projections based on the most optimistic set of assumptions. Assuming that the dynamics of the TRB, TRC, and UARB populations were independent and using the most pessimistic population-specific persistence probabilities (that is, 0.958, 0.295, and 0.849, respectively), the overall probability of persistence for bears in that population system was 0.996. Genetic methods were used to estimate interchange and structure between subpopulations in Louisiana and in Minnesota (MINN); Mississippi (MISS); and the White River Basin (WRB), Arkansas. Results from the all-population and the WRB–TRB clustering analyses indicate at least five genetically distinct populations. The genetic clustering and migrant analyses combined with capture data provided direct evidence that interchange has occurred from the WRB to the TRB and MISS, from the TRB to MISS, from the UARB to the TRC, and from the TRC to the TRB. Indirect evidence that interchange occurred from the UARB to the TRC and from the UARB to the TRB by way of the TRC was documented. No evidence was found of interchange from any of the subpopulations to the WRB, UARB, or LARB. From April 2010 to April 2012, global positioning system (GPS) radio collars were placed on 8 female and 23 male bears ranging from 1 to 11 years of age to develop a step-selection function model to predict routes and rates of interchange. For both males and females, the probability of a step being selected increased as the distance to natural land cover and agriculture at the end of the step decreased and as distance from roads at the end of a step increased. Of 4,000 correlated random walks, the least potential interchange was between TRB and TRC and between UARB and LARB, but the relative potential for natural interchange between UARB and TRC was high. The step-selection model predicted that dispersals between the LARB and UARB populations were infrequent but possible for males and nearly nonexistent for females. No evidence of natural female dispersal between subpopulations has been documented thus far, which is also consistent with model predictions.

Louisiana↗