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Research about North Carolina, Virginia, West Virginia

Source-linked reports with geographic coverage including North Carolina, Virginia, West Virginia.

9 recordsLinked to original sources
USGS2023

Genetic structure across isolated Virginia populations of the endangered candy darter (Etheostoma osburni)

Candy darter Etheostoma osburni , a federally endangered non-game fish, has been extirpated from most of its historic range in Virginia and now occurs in four isolated populations in the New River drainage. Understanding of population genetic structure will provide insights into the recent natural history of the species and can inform conservation management. Our objectives were to: characterize population genetic structure, estimate and compare effective population sizes ( N e ), and use this information to infer recent population history. Variation at mitochondrial cytochrome b sequences among 150 individuals showed 10 haplotypes separated by 1–14 mutational steps, some shared and some unique to particular populations. Variation at 12 microsatellite loci among 171 individuals showed lower variation in Dismal Creek than in other populations. All populations showed evidence of having experienced a genetic bottleneck and were highly differentiated from one another based on both types of DNA markers. Population genetic structure was related to stream position in regard to the New River, suggesting that populations were once connected. N e estimates for all populations were less than the 500 recommended to maintain evolutionary potential, but most estimates were greater than the 100 needed for use as source populations. Our findings indicate that habitat management to allow expansion of populations, and translocations to exchange genetic material among populations, may be effective tactics to promote conservation of candy darter in Virginia.

North Carolina, Virginia, West Virginia↗
USGS2023

Shallow fault slip of the 2020 M5.1 Sparta, North Carolina, earthquake

The 2020 M 5.1 Sparta, North Carolina, earthquake is the largest in the eastern United States since the 2011 M 5.8 Mineral, Virginia, earthquake and produced a ∼2.5‐km‐long surface rupture, unusual for an event of this magnitude. A geological field study conducted soon after the event indicates oblique slip along a east‐southeast‐trending fault with a consistently observed thrust component. My analysis of regional seismic waveforms, Interferometric Synthetic Aperture Radar, and Global Positioning System survey data yields a compact shallow rupture extending from Earth’s surface down‐dip to the southwest over a ∼3 km fault length. The inferred kinematic rupture is primarily toward the up‐dip and eastward along‐strike directions and has predominantly thrust motion in the west, transitioning to roughly equal thrust and left‐lateral strike‐slip motion in the east. No normal faulting component, as proposed in an earlier geophysical study, is necessary to explain the data. The prevalence of only dip‐slip motions observed at Earth’s surface may demand slip partitioning between dip slip and lateral motions at depth.

North Carolina, Virginia, West Virginia↗
USGS2022

Population genetics of Brook Trout (Salvelinus fontinalis) in the southern Appalachian Mountains

Broad-scale patterns of genetic diversity for Brook Trout remain poorly understood across their endemic range in the eastern United States. We characterized variation at 12 microsatellite loci in 22,020 Brook Trout among 836 populations from Georgia, USA to Quebec, Canada to the western Great Lakes region. Within-population diversity was typically lower in the southern Appalachians relative to the mid-Atlantic and northeastern regions. Effective population sizes in the southern Appalachians were often very small, with many estimates less than 30 individuals. The population genetics of Brook Trout in the southern Appalachians are far more complex than a conventionally held simple “northern” versus “southern” dichotomy would suggest. Contemporary population genetic variation was consistent with geographic expansion of Brook Trout from Mississippian, mid-Atlantic, and Acadian glacial refuges, as well as differentiation among drainages within these broader clades. Genetic variation was pronounced among drainages (57.4% of overall variation occurred among Hydrologic Unit Code (HUC)10 or larger units) but was considerable even at fine spatial scales (13% of variation occurred among collections within HUC12 drainage units). Remarkably, 87.2% of individuals were correctly assigned to their collection of origin. While comparisons with fish from existing major hatcheries showed impacts of stocking in some populations, genetic introgression did not overwhelm the signal of broad-scale patterns of population genetic structure. Although our results reveal deep genetic structure in Brook Trout over broad spatial extents, fine-scale population structuring is prevalent across the southern Appalachians. Our findings highlight the distinctiveness and vulnerability of many Brook Trout populations in the southern Appalachian Mountains and have important implications for wild Brook Trout management. To facilitate application of our findings by conservation practitioners, we provide an interactive online visualization tool to allow our results to be explored at management relevant scales.

North Carolina, Virginia, West Virginia↗
USGS2021

A new composite abundance metric detects stream fish declines and community homogenization during six decades of invasions

Aim We developed a new technique, utilizing species-specific counts of individuals from historical fish community samples, to examine landscape-level, spatio-temporal trends in relative abundance distributions. Abundance-based historical distribution analyses are often plagued by data comparability issues, but provide critical information about community composition trends inaccessible to those using analyses based only on species presence–absence. We established trends in native and non-native fish abundance and community homogenization, uniqueness and diversity to help local conservation managers prioritize targets and motivate similar studies globally to support fish conservation. Location Upper and middle New River (UMNR) basin, Appalachian Mountains, USA. Methods We compiled catch data from 61 years of fish community surveys (1958–2019) and tested for community homogenization by comparing data from repeatedly sampled sites (1900s versus 2000s samples) using dispersion analyses. We measured community uniqueness (site contributions to beta diversity) and species diversity (Shannon index) at sampled streams to identify potential conservation hotspots. We then used regression analyses and Wilcoxon signed-rank tests to examine species-specific basin-wide and local abundance trends and identify species of potential conservation concern. Results Dispersion of sites in species abundance space was significantly greater in the 1900s compared with the 2000s, indicating homogenization had occurred. Of 36 native species analysed, 44.4% (16) showed basin-wide declines. Non-native species exhibited mixed patterns; site-level abundance increased in 2 of 15 species analysed (13%). Main conclusions Our results indicate basin-wide community homogenization has occurred within the UMNR, but many unique and diverse communities persist. If conserved, these could help maintain regional fish diversity. We found basin-wide declines in four endemic species, as well as spread patterns of non-native and native species that were not detected by a presence–absence analysis applied within the same study area. This finding illustrates the importance of considering both species’ abundance and occurrence patterns as separate dimensions of biodiversity to inform conservation planning.

North Carolina, Virginia, West Virginia↗
USGS2001

Benthic invertebrate communities and their responses to selected environmental factors in the Kanawha River basin, West Virginia, Virginia, and North Carolina

The effects of selected environmental factors on the composition and structure of benthic invertebrate communities in the Kanawha River Basin of West Virginia, Virginia and North Carolina were investigated in 1997 and 1998. Environmental factors investigated include physiography, land-use pattern, streamwater chemistry, streambed- sediment chemistry, and habitat characteristics. Land-use patterns investigated include coal mining, agriculture, and low intensity rural-residential patterns, at four main stem and seven tributary sites throughout the basin. Of the 37 sites sampled, basin size and physiography most strongly affected benthic invertebrate-community structure. Land-use practices also affected invertebrate community structure in these basins. The basins that differed most from the minimally affected reference condition were those basins in which coal mining was the dominant nonforest land use, as determined by comparing invertebrate- community metric values among sites. Basins in which agriculture was important were more similar to the reference condition. The effect of coal mining upon benthic invertebrate communities was further studied at 29 sites and the relations among invertebrate communities and the selected environmental factors of land use, streamwater chemistry, streambed- sediment chemistry, and habitat characteristics analyzed. Division of coal-mining synoptic-survey sites based on invertebrate-community composition resulted in two groups?one with more than an average production of 9,000 tons of coal per square mile per year since 1980, and one with lesser or no recent coal production. The group with significant recent coal production showed higher levels of community impairment than the group with little or no recent coal production. Median particle size of streambed sediment, and specific conductance and sulfate concentration of streamwater were most strongly correlated with effects on invertebrate communities. These characteristics were related to mining intensity, as measured by thousands of tons of coal produced per square mile of drainage area.

North Carolina, Virginia, West Virginia↗
USGS2000

Water quality in the Kanawha-New River basin: West Virginia, Virginia, and North Carolina, 1996-98

This report summarizes major findings about water quality in the Kanawha-New River basin that emerged from an assessment conducted between 1996 and 1998 by the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program. Water quality is discussed in terms of local and regional issues and compared to conditions found in all 36 NAWQA study areas assessed to date. Findings also are explained in the context of selected national benchmarks, such as those for drinking-water quality and the protection of aquatic organisms.

North Carolina, Virginia, West Virginia↗
USGS2000

Environmental setting and its relations to water quality in the Kanawha River basin

The Kanawha River and its major tributary, the New River, drain 12,233 mi2 in West Virginia, Virginia, and North Carolina. Altitude ranges from about 550 ft to more than 4,700 ft. The Kanawha River Basin is mountainous, and includes parts of three physiographic provinces, the Blue Ridge (17 percent), Valley and Ridge (23 percent), and Appalachian Plateaus (60 percent). In the Appalachian Plateaus Province, little of the land is flat, and most of the flat land is in the flood plains and terraces of streams; this has caused most development in this part of the basin to be near streams. The Blue Ridge Province is composed of crystalline rocks, and the Valley and Ridge and Appalachian Plateaus Provinces contain both carbonate and clastic rocks. Annual precipitation ranges from about 36 in. to more than 60 in., and is orographically affected, both locally and regionally. Average annual air temperature ranges from about 43ºF to about 55ºF, and varies with altitude but not physiographic province. Precipitation is greatest in the summer and least in the winter, and has the least seasonal variation in the Blue Ridge Province. In 1990, the population of the basin was about 870,000, of whom about 25 percent lived in the Charleston, W. Va. metropolitan area. About 75 million tons of coal were mined in the Kanawha River Basin in 1998. This figure represents about 45 percent of the coal mined in West Virginia, and about seven percent of the coal mined in the United States. Dominant forest types in the basin are Northern Hardwood, Oak-Pine, and Mixed Mesophytic. Agricultural land use is more common in the Valley and Ridge and Blue Ridge Provinces than in the Appalachian Plateaus Province. Cattle are the principal agricultural products of the basin. Streams in the Blue Ridge Province and Allegheny Highlands have the most runoff in the basin, and streams in the Valley and Ridge Province and the southwestern Appalachian Plateaus have the least runoff. Streamflow is greatest in the spring and least in the autumn. About 61 percent of the basin's population use surface water from public supply for their domestic needs; about 30 percent use self-supplied ground water, and about nine percent use ground water from public supply. In 1995, total withdrawal of water in the basin was about 1,130 Mgal/d. Total consumptive use was about 118 Mgal/d. Surface water in the Blue Ridge Province is usually dilute (less than 100 mg/L dissolved solids) and well aerated. Dissolved- solids concentrations in streams of the Valley and Ridge Province at low flow are typically greater (150-180 mg/L) than those in the Blue Ridge Province. The Appalachian Plateaus Province contains streams with the most dilute (less than 30 mg/L dissolved solids) and least dilute (more than 500 mg/L dissolved solids) water in the basin. Coal mining has degraded more miles of streams in the basin than any other land use. Streams that receive coal-mine drainage may be affected by sedimentation, and typically contain high concentrations of sulfate, iron, and manganese. Other major water-quality issues include inadequate domestic sewage treatment, present and historic disposal of industrial wastes, and logging, which results in the addition of sediment, nutrients, and other constituents to the water. One hundred eighteen fish species are reported from the Kanawha River system downstream from Kanawha Falls. Of these, 15 are listed as possible, probable, or known introductions. None of these fish species is endemic to the Kanawha River Basin. The New River system has only 46 native fishes, the lowest ratio of native fishes to drainage area of any river system in the eastern United States, and the second-highest proportion of endemic fish species (eight of 46) of any river system in the eastern United States.

North Carolina, Virginia, West Virginia↗