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USGS2021

SSA task force on diversity, equity, and inclusion: Toward a changing, inclusive future in earthquake science

In the United States, a wide variety of studies show that the geoscience community does not reflect the broader societal makeup (e.g., Velasco and Jaurrieta de Velasco, 2010; Dutt, 2020; Howley, 2020). In fact, only about 10% of all Science, Technology, Engineering, and Mathematics (STEM) Ph.D. degrees are awarded to people of color, although they represent more than a third of the population (Dutt, 2020). These numbers have changed little over the past 40 yr (e.g., Bernard and Cooperdock, 2018; Dutt, 2020). Recent events in the United States have again raised awareness of this discrepancy in many fields; similar divergences may be present throughout the world. This discrepancy represents a tremendous loss of talent and contributes to ongoing bias and racism. As the premier international seismological professional society, Seismological Society of America (SSA) is committed, as stated in its ethics policy, to “freedom and transparency in research and education, which should be conducted in a supportive, inclusive, and respectful environment, free from any discrimination, harassment or bullying.” SSA convened the SSA Diversity, Equity, and Inclusion (DEI) Task Force to identify specific and actionable recommendations that the Society can take to start to address the significant issues surrounding the systematic underrepresentation in seismology and related geosciences by marginalized groups on both short- and long- term time horizons. This report, written by the Task Force, outlines actionable items that SSA can undertake as well as a framework by which progress can be measured to help guide the Society and its members forward as a community to make earthquake science more just, equitable, diverse, and inclusive. We recognize that this document cannot address the multiple individual, cultural, and historical barriers that some members may face (e.g., Núñez et al., 2020), nor can it reflect all possibilities or all recommended practices (e.g., Ali et al., 2021). What this document does represent, however, is the beginning of what we hope to be a significant cultural change in how we conduct earthquake science as an organization, not the end of this process as the Task Force fulfills its charter. As a note, some of the recommendations that the Task Force has outlined here have already been implemented within SSA or are actively being considered. For completeness, we still include them here because this highlights the commitment to change that SSA leadership has embraced.

Seismological Research Letters↗
USGS2010

Silurian-Devonian age and tectonic setting of the Connecticut Valley-Gaspé trough of Vermont using U-Pb SHRIMP analyses of detrital zircons

U-Pb SHRIMP ages of detrital zircons from metasedimentary rocks of the Connecticut Valley-Gaspe' trough in Vermont corroborate a Silurian-Devonian age of deposition for these strata and constrain their provenances. Ages of randomly selected detrital zircons obtained from quartzites within the Waits River and Gile Mountain Formations range from Archean to Devonian with Mesoproterozoic, Neoproterozoic, Ordovician, and Silurian age populations suggesting both eastern and western sources of the sediments. The two youngest single-grain detrital zircon ages from samples collected in the Waits River Formation are 418 ± 7 and 415 ± 2 Ma. The youngest single-grain detrital zircon age from the eastern part of the Gile Mountain Formation is 411 ± 8. The youngest detrital zircons from the western portion of the Gile Mountain Formation comprise an age population with a weighted average of 409 ± 5 Ma. These~409 Ma zircons are likely of volcanic origin, perhaps derived from the Piscataquis magmatic belt to the east. The absence of younger volcanic zircons in the coarser-grained eastern facies of the Gile Mountain Formation suggests the eastern sediments are older and were buried during Piscataquis volcanism and deposition in the west. The shift in protoliths from calcareous silts and muds of the Waits River Formation to quartzo-feldspathic sands of the Gile Mountain Formation implies a change from a continental slope-like depositional environment to a near-shore or terrestrial environment of deposition. This change supports a transition in the nature of the basin from an intercontinental back-arc extensional setting to a foreland basin setting. Maximum depositional ages of sediments above and below this facies boundary constrain the timing of transition in basin style between about 415 and 411 Ma. Given the timing of the approaching Acadian wedge, this shift in basin style likely reflects westward migration of thrust sheets during the Acadian orogeny. The finegrained nature of the youngest silts, muds and turbidites suggests that sedimentation occurred in increasingly deeper water. The implied basin subsidence was likely caused by lithospheric flexure as the Acadian wedge approached from the east. The timing of this subsidence is constrained to be younger than the youngest zircons at about 409 Ma.

Vermont↗
USGS2001

Reconnaissance for trace metals in bed sediment, Wright Patman Lake, near Texarkana, Texas

Many contaminants can be introduced into the environment by urban and industrial activities. The drainage area of Wright Patman Lake is influenced by these activities. Among the contaminants associated with urban and industrial activities are trace metals such as arsenic, lead, mercury, and zinc. These contaminants are relatively insoluble in water and commonly are found in stream, lake, and reservoir bottom sediment, especially the clays and silts within the sediment. Wright Patman Lake serves as the major potable water supply for the city of Texarkana and surrounding communities. Texarkana, located in the northeastern corner of Texas and the southwestern corner of Arkansas, had a population of about 56,000 in 1998, which reflects an increase of about 3.4 percent from the 1990 census (Ramos, 1999). Texarkana Water Utilities, which manages the water-treatment facilities for Texarkana, proposes to dredge the lake bed near the water intake in the Elliot Creek arm of Wright Patman Lake. It is possible that arsenic, lead, mercury, and other trace metals might be released into the water if the bed sediment is disturbed. Bed sediment in the Elliot Creek arm of the lake, in particular, could contain trace metals because of its proximity to Red River Army Depot and because industrial land use is prevalent in the headwaters of Elliot Creek. The U.S. Geological Survey (USGS), in cooperation with Reconnaissance for Trace Metals in Bed Sediment, Wright Patman Lake, Near Texarkana, Texas In cooperation with the Texarkana Water Utilities conducted a reconnaissance of Wright Patman Lake to collect bed-sediment samples for analysis of trace metals. This report presents trace metal concentrations in bed-sediment samples collected at six sites along the Elliot Creek arm of the lake, one site each in two adjacent arms, and one site near the dam on June 16, 1999 (fig. 1). One bed-sediment sample was collected at each of the nine sites, and one sediment core was collected at each of two of the sites. Trace metal concentrations are compared to sediment-quality guidelines for the protection of aquatic life and to screening levels based on historical trace metal concentrations in bed sediment of Texas reservoirs.

Texas↗
USGS2004

Movement behavior, dispersal, and the potential for localized management of deer in a suburban environment

We examined the potential for localized management of white-tailed deer ( Odocoileus virginianus ) to be successful by measuring movements, testing site fidelity, and modeling the effects of dispersal. Fifty-nine females were radiomarked and tracked during 1997 through 2000 in Irondequoit, New York, USA, a suburb of Rochester. We constructed home ranges for those deer with A greater than or equal to 18 reclocations/season. Fifty percent minimum convex polygons (MCP) averaged 3.9 (SE = 0.53) ha in the summer and 5.3 (SE = 0.80) ha in the winter. Deer showed strong fidelity to both summer and winter home ranges, and 30 of 31 females showed overlap of summer and winter home ranges. Annual survival was 64%; the major cause of mortality was deer-automobile collisions. Average annual dispersal rates were <15% for yearlings and adults. Using matrix population modeling, we explored the role of female dispersal in sustaining different management objectives in adjacent locales of approximately 1,000 ha. Modeling showed that if female dispersal was 8%, culling would have to reduce annual survival to 58% to maintain a population just under ecological carrying capacity and reduce survival to 42% to keel) the population at one-half carrying capacity. With the same dispersal, contraception Would need to be effective in 32% of females if the population is near carrying capacity and 68% if the population is at one-half of carrying capacity. Movement behavior data and modeling results lend support to the use of a localized approach to management of females that emphasizes neighborhood-scale manipulation of deer populations, but our research suggests that dispersal rates in females could be critical to long-term success.

New York↗
USGS2015

Landscape disturbance from unconventional and conventional oil and gas development in the Marcellus Shale region of Pennsylvania, USA

The spatial footprint of unconventional (hydraulic fracturing) and conventional oil and gas development in the Marcellus Shale region of the State of Pennsylvania was digitized from high-resolution, ortho-rectified, digital aerial photography, from 2004 to 2010. We used these data to measure the spatial extent of oil and gas development and to assess the exposure of the extant natural resources across the landscape of the watersheds in the study area. We found that either form of development: (1) occurred in ~50% of the 930 watersheds that defined the study area; (2) was closer to streams than the recommended safe distance in ~50% of the watersheds; (3) was in some places closer to impaired streams and state-defined wildland trout streams than the recommended safe distance; (4) was within 10 upstream kilometers of surface drinking water intakes in ~45% of the watersheds that had surface drinking water intakes; (5) occurred in ~10% of state-defined exceptional value watersheds; (6) occurred in ~30% of the watersheds with resident populations defined as disproportionately exposed to pollutants; (7) tended to occur at interior forest locations; and (8) had >100 residents within 3 km for ~30% of the unconventional oil and gas development sites. Further, we found that exposure to the potential effects of landscape disturbance attributable to conventional oil and gas development was more prevalent than its unconventional counterpart.

Pennsylvania↗
USGS1979

Alcoholic fermentation in swamp and upland populations of Nyssa sylvatica: Temporal changes in adaptive strategy

Both the upland and swamp varieties of Nyssa sylvatica respond initially to flooding with an acceleration of ethanol production. Under continued flooding the roots of the upland variety sylvatica have decreased rates of ethanol production, very likely a result of the progressively worsening necrosis of the root system. Few of these plants survive a full year of flooding. The swamp variety biflora survives and grows well under flooded conditions due to sequential metabolic and anatomical changes in the roots. Within a month after flooding, var. biflora initiates new roots with greatly accelerated rates of ethanol production, perhaps providing for a short-term compensatory energy source. Long-term acclimation to flooding involves a replacement of these roots and increased oxygen transport to the roots. The hypoxic conditions of the soil environment are avoided, and these rates of ethanol production are similar to those of drained plants.

American Naturalist↗
USGS2013

Effectiveness of an integrated hatchery program: Can genetic-based performance differences between hatchery and wild Chinook salmon be avoided?

Performance of wild (W) and hatchery (H) spring Chinook salmon ( Oncorhynchus tshawytscha ) was evaluated for a sixth generation hatchery program. Management techniques to minimize genetic divergence from the wild stock included regular use of wild broodstock and volitional releases of juveniles. Performance of HH, WW, and HW (hatchery female spawned with wild male) crosses was compared in hatchery and stream environments. The WW juveniles emigrated from the hatchery at two to three times the rate of HH fish in the fall (HW intermediate) and 35% more HH than WW adults returned (27% more HW than WW adults). Performance in the stream did not differ statistically between HH and WW fish, but outmigrants (38% WW, 30% HW, and 32% HH fish) during the first 39 days of the 16-month sampling period composed 74% of total outmigrants. Differences among hatchery-reared crosses were partially due to additive genetic effects, were consistent with domestication (increased fitness for the hatchery population in the hatchery program), and suggested that selection against fall emigration from the hatchery was a possible mechanism of domestication.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2024

Detection and transport of environmental DNA from two federally endangered mussels

Environmental DNA (eDNA) offers a novel approach to supplement traditional surveys and provide increased spatial and temporal information on species detection, and it can be especially beneficial for detecting at risk or threatened species with minimal impact on the target species. The transport of eDNA in lotic environments is an important component in providing more informed descriptions of where and when a species is present, but eDNA transport phenomena are not well understood. In this study, we used species-specific assays to detect eDNA from two federally endangered mussels in two geographically distinct rivers. Using the eDNA concentrations measured from field samples, we developed a one-dimensional (1D) hydrodynamic transport model to predict the downstream fate and transport of eDNA. We detected eDNA from both federally endangered mussels across several seasons and flow rates and up to 3.5 km downstream from the source populations, but the detection rates and eDNA concentrations were highly variable across and within rivers and study reaches. Our 1D transport models successfully integrated the variability of the eDNA field samples into the model predictions and overall model results were generally within ±1 standard error of the eDNA field concentration values. Overall, the results of this study demonstrate the importance of optimizing the spatial locations from where eDNA is collected downstream from a source population, and it highlights the need to improve understanding on the shedding mechanisms and magnitude of eDNA from source populations and biogeomorphic processes that influence eDNA transport.

Missouri, Tennessee↗
USGS2020

Testing environmental DNA from wolf snow tracks for species, sex, and individual identification

Monitoring elusive, relatively low-density, large predators, such as the grey wolf (Canis lupus), has often been accomplished by live-capture and radiocollaring. Increasingly, non-invasive methods are considered best practice whenever it is possible to use them. Recently, environmental DNA (eDNA) deposited in snow tracks was demonstrated as useful for identifying lynx (Lynx canadensis), fisher (Pekania pennanti), wolverine (Gulo gulo), sika deer (Cervus nippon), red fox (Vulpes vulpes), and the Japanese marten (Martes melampus) to species level using mitochondrial DNA (mtDNA) markers. We tested whether eDNA from fresh wolf snow tracks collected in the Superior National Forest, Minnesota, USA during winter 2019 could be used to identify species, sex, and individual. Seven of the 8 snow track samples were successfully identified to “wolf-dog” species using mtDNA, with alleles amplifying in 5 of the samples at 1 or both of loci u250 and FH2096 in the allele range for wolves for this population. None yielded enough high-quality DNA to obtain genotypes to determine individual or sex. We recommend additional field trials to determine the minimum number of tracks required per individual to obtain sufficient, high-quality eDNA, as well as collecting associated urine or blood (from estrus) when possible. If individual wolves could be identified and sexed by the eDNA in their snow tracks, researchers should be able to determine population and family or group metrics with greater precision and less effort than typically required when conducting winter scat or hair-based genetic field studies of low density, elusive carnivores. Furthermore, this method would have applications to other areas of research and management, such as hunting quota determinations, validation of field methods and, in particular regards to wolves and other predators, livestock depredation issues. Overall, this technique holds significant future promise as field and laboratory methods are further refined for greater precision and optimized regarding the varying collection, filtration, and extraction protocols for different species in various environments.

Minnesota↗
USGS1969

Factors initiating phytoplankton blooms and resulting effects on dissolved oxygen in Duwamish River estuary, Seattle, Washington

Phytoplankton productivity, standing stock, and related environmental factors were studied during 1964-66 in the Duwamish River estuary, at Seattle, Wash., to ascertain the factors that affect phytoplankton growth in the estuary; a knowledge of these factors in turn permits the detection and evaluation of the influence that effluent nutrients have on phytoplankton production. The factors that control the concentration of dissolved oxygen were also evaluated because of the importance of dissolved oxygen to the salmonid populations that migrate through the estuary. Phytoplankton blooms, primarily of diatoms, occurred in the lower estuary during August 1965 and 1966. No bloom occurred during 1964, but the presence of oxygen-supersaturated surface water in August 1963 indicates that a bloom did occur then. Nutrients probably were not the primary factor controlling the timing of phytoplankton blooms. Ammonia ,and phosphate concentrations increased significantly downstream from the Municipality of Metropolitan Seattle's Renton Treatment Plant outfall after the plant began operation in June 1965, and concentrations of nitrogen and phosphorus were relatively high before operation of the Renton Treatment Plant and during nonbloom periods. The consistent coincidence of blooms with minimum fresh-water discharge and tidal exchange during August throughout the study period indicates that bloom timing probably was controlled mostly by hydrographic factors that determine retention time and stability of the surface-water layer. This control was demonstrated in part by a highly significant correlation of gross productivity with retention time (as indicated by fresh-water discharge) and vertical stability (as indicated by the difference between mean surface and mean bottom temperatures). The failure of a bloom to develop in 1964 is related to a minimum fresh-water discharge that was much greater than normal during that summer. Hydrographic factors are apparently important because, as shown by studies of other estuarine environments by other workers, phytoplankton production increases when the zone of vertical turbulent mixing is not markedly deeper than the compensation depth. Phytoplankton cells produced in the surface waters sink, thereby contributing oxidizable organic matter to the bottom saline-water wedge. The maximum BOD (biochemical oxygen demand) in this bottom wedge occurs in the same section of the estuary and ,at the same time as the maximum phytoplankton biomass (as indicated by chlorophyll a) and minimum DO (dissolved oxygen). Other sources of BOD occur in the estuary, and conditions of minimum discharge and tidal exchange assist in reducing DO. Nonetheless, the highly significant correlation of chlorophyll a with BOD throughout the summer indicates that respiration and decomposition of phytoplankton cells is dearly an important contributor of BOD. Increases in the biomass and resultant B0D of blooms because of increased effluent nutrients presumably would further decrease the concentration of DO. This possible effect of effluent nutrients was evaluated by laboratory .bioassays and by a comparison of mean annual biomasses in the estuary. A green algal population in vitro did increase in response to added effluent nutrients; however, the available field data suggest that a 46-percent increase in effluent discharge between 1965 and 1966 did not increase the estuary's phytoplankton biomass significantly.

Water Supply Paper↗
USGS2015

Environmental predictors of shrubby cinquefoil ( Dasiphora fruticosa ) habitat and quality as host for Maine’s endangered Clayton’s copper butterfly ( Lycaena dorcas claytoni )

Population size of habitat-specialized butterflies is limited in part by host plant distribution and abundance. Effective conservation for host-specialist species requires knowledge of host-plant habitat conditions and relationships with the specialist species. Clayton’s copper butterfly ( Lycaena dorcas claytoni ) is a Maine state-endangered species that relies exclusively on shrubby cinquefoil ( Dasiphora fruticosa ) as its host. Dasiphora fruticosa occurs in 28 wetlands in Maine, ten of which are occupied by L. d. claytoni. Little is known about environmental conditions that support large, persistent stands of D. fruticosa in Maine. We evaluated the environment (hydrology, pore water and peat nutrients) associated with D. fruticosa distribution, age, and condition in Maine wetlands supporting robust stands of D. fruticosa to compare with L. d. claytoni occurrence. Although dominant water source in D. fruticosa —containing wetlands included both groundwater discharge and surface-flow, D. fruticosa coverage was greater in wetlands with consistent growing season water levels that dropped into or below the root zone by late season, and its distributions within wetlands reflected pore water hydrogen ion and conductivity gradients. Flooding magnitude and duration were greatest during the L.d. claytoni larval feeding period, whereas, mean depth to water table and upwelling increased and were most variable following the L. d. claytoni egg-laying period that precedes D. fruticosa senescence. Oldest sampled shrubs were 37 years, and older shrubs were larger and slower-growing. Encounter rates of L. d. claytoni were greater in wetlands with larger D. fruticosa plants of intermediate age and greater bloom density. Wetland management that combines conditions associated with D. fruticosa abundance (e.g., non-forested, seasonally consistent water levels with high conductivity) and L. d. claytoni occurrence (e.g., drawdown below the root zone following egg-laying, abundant blooms on intermediate-aged D. fruticosa, nearby D. fruticosa -containing wetlands) will aid L. d. claytoni conservation.

Wetlands Ecology and Management↗
USGS2014

Mercury accumulation in sea lamprey ( Petromyzon marinus ) from Lake Huron

We determined whole-fish total mercury (Hg) concentrations of 40 male and 40 female adult sea lampreys ( Petromyzon marinus ) captured in the Cheboygan River, a tributary to Lake Huron, during May 2011. In addition, bioenergetics modeling was used to explore the effects of sex-related differences in activity and resting (standard) metabolic rate (SMR) on mercury accumulation. The grand mean for Hg concentrations was 519 ng/g (standard error of the mean = 46 ng/g). On average, males were 16% higher in Hg concentration than females. Bioenergetics modeling results indicated that 14% higher activity and SMR in males would account for this observed sex difference in Hg concentrations. We concluded that the higher Hg concentration in males was most likely due to higher rate of energy expenditure in males, stemming from greater activity and SMR. Our findings have implications for estimating the effects of sea lamprey populations on mercury cycling within ecosystems, as well as for the proposed opening of sea lamprey fisheries. Eventually, our results may prove useful in improving control of sea lamprey, a pest responsible for substantial damage to fisheries in lakes where it is not native.

Michigan↗
USGS2024

Landscape fragmentation overturns classical metapopulation thinking

Habitat loss and isolation caused by landscape fragmentation represent a growing threat to global biodiversity. Existing theory suggests that the process will lead to a decline in metapopulation viability. However, since most metapopulation models are restricted to simple networks of discrete habitat patches, the effects of real landscape fragmentation, particularly in stochastic environments, are not well understood. To close this major gap in ecological theory, we developed a spatially explicit, individual-based model applicable to realistic landscape structures, bridging metapopulation ecology and landscape ecology. This model reproduced classical metapopulation dynamics under conventional model assumptions, but on fragmented landscapes, it uncovered general dynamics that are in stark contradiction to the prevailing views in the ecological and conservation literature. Notably, fragmentation can give rise to a series of dualities: a) positive and negative responses to environmental noise, b) relative slowdown and acceleration in density decline, and c) synchronization and desynchronization of local population dynamics. Furthermore, counter to common intuition, species that interact locally (“residents”) were often more resilient to fragmentation than long-ranging “migrants.” This set of findings signals a need to fundamentally reconsider our approach to ecosystem management in a noisy and fragmented world.

PNAS↗
USGS2026

Enduring cultural legacies affect Euro-American wildlife values

Social values shape biodiversity conservation success. Yet information is lacking on how values form, change and adapt people to their environment. Our 33-nation survey in 2021–2023 ( n = 18,477) explored the effect of the institutions of European colonization on present-day values towards wildlife in the Americas. Here we found mutualism values (seeing wildlife as part of one’s social community) prevail in Iberian-origin Latin American countries, whereas domination values (seeing wildlife as a resource for human use) are more prevalent in British-origin North American countries. Multilevel analysis showed significant country-level effects of colonial institution (for example, colonial origin, Protestant versus Catholic religious cultures) and endowment (for example, pre-colonial population density, Indigenous ancestry, settler mortality) factors on wildlife values in the Americas. The strong mutualism emphasis in Latin America appears to be consistent with acculturation between the compatible ideologies of Indigenous peoples and the Iberian colonizers. The effectiveness of wildlife institutions and policies will depend on their congruence with the social values of publics being served.

Nature Sustainability↗
USGS2023

Bighorn sheep associations: Understanding tradeoffs of sociality and implications for disease transmission

Sociality directly influences mating success, survival rates, and disease, but ultimately likely evolved for its fitness benefits in a challenging environment. The tradeoffs between the costs and benefits of sociality can operate at multiple scales, resulting in different interpretations of animal behavior. We investigated the influence of intrinsic ( e.g. , relatedness, age) and extrinsic factors ( e.g. , land cover type, season) on direct contact (simultaneous GPS locations ≤ 25 m) rates of bighorn sheep ( Ovis canadensis ) at multiple scales near the Waterton-Glacier International Peace Park. During 2002–2012, male and female bighorn were equipped with GPS collars. Indirect contact (GPS locations ≤ 25 m regardless of time) networks identified two major breaks whereas direct contact networks identified an additional barrier in the population, all of which corresponded with prior disease exposure metrics. More direct contacts occurred between same-sex dyads than female-male dyads and between bighorn groups with overlapping summer home ranges. Direct contacts occurred most often during the winter-spring season when bighorn traveled at low speeds and when an adequate number of bighorn were collared in the area. Direct contact probabilities for all dyad types were inversely related to habitat quality, and differences in contact probability were driven by variables related to survival such as terrain ruggedness, distance to escape terrain, and canopy cover. We provide evidence that probabilities of association are higher when there is greater predation risk and that contact analysis provides valuable information for understanding fitness tradeoffs of sociality and disease transmission potential.

Alberta, British Columbia, Montana↗
USGS1978

Water resources inventory of Connecticut Part 8: Quinnipiac River basin

The Quinnipiac River basin area in southcentral Connecticut covers 363 square miles, and includes all drainage basins that enter Long Island Sound from the Branford to the Wepawaug Rivers. Its population in 1970 was estimated at 535,000. Precipitation averages 47 inches per year and provides an abundant supply of water. Twenty-one inches returns to the atmosphere as evapotranspiration; the remainder flows directly to streams or percolates to the water table and discharges to Long Island Sound. Small amounts of water are exported from the basin by the New Britain Water Department, and small amounts are imported to the basin by the New Haven Water Company. The amount of water that can be developed at a given place depends upon precipitation, variability of streamflow, hydraulic properties and areal extent of the aquifers, and hydraulic connection between the aquifers and major streams. The quality of the water is determined by the physical environment and the effects of man. Stratified drift is the only aquifer capable of large sustained yields of water to individual wells. Yields of 64 screened wells tapping stratified drift range from 17 to 2,000 gpm (gallons per minute); their median yield is 500 gpm. Till is widespread and generally provides only small amounts of water. Wells in till normally yield only a few hundred gallons of water daily and commonly are inadequate during dry periods. Till is generally used only as an emergency or secondary source of water. Bedrock aquifers underlie the entire report area and include sedimentary, igneous, and metamorphic rock types. These aquifers supply small but reliable quantities of water to wells throughout the basin and are the chief source for many nonurban homes and farms. About 90 percent of the wells tapping bedrock yield at least 2 pgm, and much larger yields are occasionally reported. Maximum well yields of 305 gpm for sedimentary, 75 gpm for igneous, and 200 gpm for metamorphic bedrock have been reported. Water potentially available from stratified drift was estimated on the basis of hydraulic characteristics of the aquifers and evaluation of natural and induced recharge. Long-term yields estimated for 14 favorable areas of stratified drift range from 0.8 to 16.1 mgd (million gallons per day), but detailed verification studies are needed before development. The natural quality of water in the report area is good. The water is generally low in dissolved solid and is soft to moderately hard. Surface water is less mineralized than ground water, especially during high flow when it is primarily surface runoff. A median dissolved-solids concentration of 117 mg/l (milligrams per liter) and a median hardness of 58 mg/l was determined for water samples collected at 20 sites on 16 streams during high flow. A median dissolved-solids concentration of 146 mg/l and a median hardness of 82 mg/l was determined for samples collected at the same sites during low flow. In contrast water from 130 wells had a median dissolved-solids concentration of 188 mg/l and a median hardness of 110 mg/l. Iron and manganese occur in objectionable concentrations in parts of the report area, particularly in water from streams draining swamps and in water from aquifers rich in iron- and manganese-bearing minerals. Concentrations of iron in excess of 0.3 mg/l were found in 40 percent of the high-streamflow samples, 59 percent of the low-streamflow samples and 20 percent of the ground-water samples. Human activities have modified the quality of water in much of the basin. Wide and erratic fluctuations in concentration of dissolved solids in streams, high bacterial content of the Quinnipiac River, and locally high nitrate and chloride concentrations in ground water are evidence of man's influence. Streams, wetlands, and some aquifers along the southern boundary of the basin contain salty water. Overpumping has caused extensive saltwater intrusion in aquifers in the southern and eastern parts of New Haven. The total amount of fresh water used in the area during 1970 is estimated at 35,710 million gallons, or 183 gallons per day per capita. Public water-supply systems met the domestic requirements of about 90 percent of the population; all the systems supplied water that met the drinking water standards of the Connecticut Department of Health.

Connecticut↗
USGS2020

Forecasting water demand across a rapidly urbanizing region

Urban growth and climate change together complicate planning efforts meant to adapt to increasingly scarce water supplies. Several studies have independently examined the impacts of urban planning and climate change on water demand, but little attention has been given to their combined impact. Here we forecast urban water demand using a Geographically Weighted Regression model informed by socio-economic, environmental and landscape pattern metrics. The purpose of our study is to evaluate how future scenarios of population densities and climate warming will jointly affect water demand across two rapidly growing U.S. states (North Carolina and South Carolina). Our forecasts indicate that regional water demand by 2065 will increase by 37%–383% relative to the baseline in 2010, across all scenarios of change. Our results show future water demand will increase under rising temperatures, but could be ameliorated by policies that promote higher density development and urban infill. These water-efficient land use policies show a 5% regional reduction in water demand and up to 25% reduction locally for counties with the highest expected population growth by 2065. For rural counties experiencing depopulation, the land use policies we considered are insufficient to significantly reduce water demand. For expanding communities seeking to increase their adaptive capacity to changing socio-environmental conditions, our framework can assist in developing sustainable solutions.

North Carolina, South Carolina↗
USGS2021

Flow dynamics influence fish recruitment in hydrologically connected river-reservoir landscapes

Hydrologic processes are often important determinants of successful recruitment of native fishes. However, water management practices can result in abnormal changes in daily and seasonal hydrology patterns. Rarely has fish recruitment across river–reservoir landscapes been considered in relation to flow management, despite the direct relationship between reservoir water management and the resulting upstream and downstream hydrology. We evaluated the relationships between lotic and lentic hydrology and recruitment of two native broadcast-spawning fishes, Freshwater Drum Aplodinotus grunniens and Gizzard Shad Dorosoma cepedianum . Four seasonal periods for each species were identified that related to the species’ spawning biology, from which we derived our remaining hydrology variables. Annual hydrology variables were also considered in our analysis. We developed regression models in conjunction with a model-selection procedure for each species and habitat type based on the catch-curve residuals from fish populations in hydrologically connected river–reservoir systems in the Ozark Highland and Ouachita Mountain ecoregions, USA. Our results indicated that recruitment of reservoir Freshwater Drum was negatively correlated to annual reservoir retention time. In lotic habitats, Freshwater Drum recruitment was positively correlated with prespawn discharge conditions and negatively correlated with annual flow variability. Similarly, riverine Gizzard Shad recruitment was positively correlated to the frequency of high-flow pulses during the spawning period. Our results indicate that releasing reservoir water to best mimic relatively natural flow patterns may benefit some broadcast-spawning species that occupy both lentic and downstream lotic environments, especially during the spring. This information, combined with future efforts on additional spawning guilds, will provide a foundation for developing holistic river–reservoir water-allocation plans.

Missouri, Oklahoma↗