Geology topics

Serena Ciparis

Publications and source records attributed to Serena Ciparis.

9 recordsLinked to original sources

USGS2026

Stream health shows indirect and threshold responses to implementation of agricultural conservation practices

Many agricultural conservation practices (hereafter conservation practices) are intended to protect streams from the deleterious effects of agriculture, but desired effects of their implementation are not always realized. Understanding the pathways through which conservation practices influence stream health can guide future implementation. Our goal was to quantify how conservation practices influence stream health in pastureland watersheds. We asked 4 research questions: R1) What are the effects of land use and conservation practices on instream conditions? R2) What are the effects of instream conditions on biota? R3) What are the relative effects of land use, conservation practices, and instream conditions on biota? R4) How do conservation practice density (no./ha) and agricultural land use interact to influence stream health? We collected data on water quality (total suspended solids, total N, total P, and Escherichia coli bacteria), instream habitat (substrate embeddedness and bank stability), and macroinvertebrate communities from 31 sites in the upper Tennessee River basin of southwest Virginia, USA. The sites collectively represented spatial analytical gradients of agricultural land use and density of conservation practices, with the dominant practices including prescribed grazing, brush management, and fencing. We found that conservation practice implementation was indirectly related to biotic assemblages through changes in water quality and habitat, but practice density in the study area was not associated with instream conditions that supported biotic communities representative of reference conditions. Further improving instream habitat conditions may require innovative conservation practices, targeted placement of practices in critical source areas of pollutants, or higher densities of practices.

Virginia↗

USGS2026

Development of a SWAT+ model to improve conservation practice efficacy for protecting stream health in karst pasturelands

Placing appropriate conservation practices in critical source areas of pollutants can benefit stream health in karst environments susceptible to agricultural pollution. Watershed models, such as the Soil and Water Assessment Tool+ (SWAT+), can optimize both practice selection and placement across the landscape, but to our knowledge no studies have tested this model in karst pasturelands. Our goal was to understand pollutant dynamics in pasturelands with karst topography in southwest Virginia, United States. We built a SWAT+ model to predict streamflow and pollutant loads for four watersheds. SWAT+ predicted that streamflow estimates were most affected by setting the available water capacity to zero and increasing the hydraulic conductivity of the soil, revealing that water, and associated pollutants, move primarily through subsurface pathways. Predicted sediment yield was negatively associated with agricultural land cover and was strongly influenced by channel erodibility—indicating that the predominant sediment source may be streambanks. Therefore, practices that stabilize stream banks (e.g., fencing cattle out of streams) may be most effective at reducing sediment loads. The model unsatisfactorily predicted total nitrogen and total phosphorus loads. The utility of SWAT+ for cattle grazing operations in karst regions could be improved by more accurately representing the effects of cattle grazing on streambank erosion and the dynamic subsurface movement of pollutants.

Virginia↗

USGS2025

Landowners' cognitions and motivations coupled with practice durability influence persistence in grazing agricultural conservation practices in southwest Virginia

Agricultural conservation practices are often used to protect stream health while continuing food production. However, recovery of stream health is often not as rapid or extensive as planned. The efficacy of practices may be improved by promoting their continued use by landowners (i.e., persistence) after cost-share contracts with government agencies end. Persistence rates and their drivers are typically unknown. Therefore, we mail-surveyed 889 landowners to understand persistence in grazing practices in southwest Virginia. Survey responses were analyzed quantitatively using logistic regression and qualitatively via coding. We found that persistence rates for vegetative practices, cattle-exclusion fencing, off-stream watering structures, and pasture management were 74%, 84%, 94%, and 94%, respectively. Both the quantitative and qualitative analyses indicated that landowner cognitions (i.e., attitudes toward practices, environment, and agencies), environmental motivations, and practice durability influence persistence. Our results highlight that persistence could be encouraged by: (1) providing targeted messaging that demonstrates persistence benefits and aligns with landowners' motivations, (2) ensuring that responsibility to maintain practices is transferred during land-tenure changes, and (3) allocating more agency funding to practice maintenance.

Virginia↗

USGS2023

Ecological harm and economic damages of chemical contamination to linked aquatic-terrestrial food webs: A study-design tool for practitioners

Contamination of aquatic ecosystems can have cascading effects on terrestrial consumers by altering the availability and quality of aquatic insect prey. Comprehensive assessment of these indirect food-web effects of contaminants on natural resources and their associated services necessitates using both ecological and economic tools. In the present study we present an aquatic-terrestrial assessment tool (AT2), including ecological and economic decision trees, to aid practitioners and researchers in designing contaminant effect studies for linked aquatic-terrestrial insect-based food webs. The tool is tailored to address the development of legal claims by the US Department of the Interior's Natural Resource Damage Assessment and Restoration Program, which aims to restore natural resources injured by oil spills and hazardous substance releases into the environment. Such cases require establishing, through scientific inquiry, the existence of natural resource injury as well as the determination of the monetary or in-kind project-based damages required to restore this injury. However, this tool is also useful to researchers interested in questions involving the effects of contaminants on linked aquatic-terrestrial food webs. Stylized cases exemplify how application of AT2 can help practitioners and researchers design studies when the contaminants present at a site are likely to lead to injury of terrestrial aerial insectivores through loss of aquatic insect prey and/or dietary contaminant exposure. Designing such studies with ecological endpoints and economic modeling inputs in mind will increase the relevance and cost-effectiveness of studies, which can in turn improve the outcomes of cases and studies involving the ecological effects of contaminants on food webs.

Environmental Toxicology and Chemistry↗

USGS2023

Survival and growth of juvenile mussels in an outdoor pond after 28-day laboratory exposure to aqueous zinc

The extent to which effects seen in chronic toxicity studies in the laboratory affect mussel fitness later in life is poorly known. We examined juvenile Fatmucket ( Lampsilis siliquoidea ) survival and growth for 56 d following exposure to Zn in a laboratory bioassay. We conducted a 28-d chronic toxicity bioassay with 6-wk-old juvenile mussels exposed to a control and two Zn treatments (120 and 240 µg/L). We then transferred surviving mussels into a grow-out pond and monitored their survival and growth for 56 d. Survival and shell length were lower in both Zn treatments than in the control after the 28-d toxicity bioassay. After the 56-d grow-out period, survival did not differ among treatments, but shell length was lower in the 240-µg/L treatment than in the control and mass was lower in both Zn treatments than in the control. Mussel length was lower throughout the experiment in both Zn treatments than in the control, but there was weak support for a difference in the slopes, suggesting that Zn-exposed mussels may fall farther behind in size over time. Persistence of reduced size following Zn exposure could result in delayed sexual maturation and lowered fecundity, which could have long-term population-level effects.

Freshwater Mollusk Biology and Conservation↗

USGS2021

Method development for a short-term 7-day toxicity test with unionid mussels

The US Environmental Protection Agency's short-term freshwater effluent test methods include a fish ( Pimephales promelas ), a cladoceran ( Ceriodaphnia dubia ), and a green alga ( Raphidocelis subcapitata ). There is a recognized need for additional taxa to accompany the three standard species for effluent testing. An appropriate additional taxon is unionid mussels because mussels are widely distributed, live burrowed in sediment and filter particles from the water column for food, and exhibit high sensitivity to a variety of contaminants. Multiple studies were conducted to develop a relevant and robust short-term test method for mussels. We first evaluated the comparative sensitivity of two mussel species ( Villosa constricta and Lampsilis siliquoidea ) and two standard species ( P. promelas and C. dubia ) using two mock effluents prepared by mixing ammonia and five metals (cadmium, copper, nickel, lead, and zinc) or a field-collected effluent in 7-day exposures. Both mussel species were equally or more sensitive (more than two-fold) to effluents compared with the standard species. Next, we refined the mussel test method by first determining the best feeding rate of a commercial algal mixture for three age groups (1, 2, and 3 weeks old) of L. siliquoidea in a 7-day feeding experiment, and then used the derived optimal feeding rates to assess the sensitivity of the three ages of juveniles in a 7-day reference toxicant (sodium chloride [NaCl]) test. Juvenile mussels grew substantially (30%–52% length increase) when the 1- or 2-week-old mussels were fed 2 ml twice daily and the 3-week-old mussels were fed 3 ml twice daily. The 25% inhibition concentrations (IC25s) for NaCl were similar (314–520 mg Cl/L) among the three age groups, indicating that an age range of 1- to 3-week-old mussels can be used for a 7-day test. Finally, using the refined test method, we conducted an interlaboratory study among 13 laboratories to evaluate the performance of a 7-day NaCl test with L. siliquoidea . Eleven laboratories successfully completed the test, with more than 80% control survival and reliable growth data. The IC25s ranged from 296 to 1076 mg Cl/L, with a low (34%) coefficient of variation, indicating that the proposed method for L. siliquoidea has acceptable precision. Environ Toxicol Chem 2021;40:3392–3409. © 2021 SETAC

Environmental Toxicology and Chemistry↗

USGS2020

Coal-mining intensity influences species and trait distributions of stream fishes in two Central Appalachian watersheds

Documenting responses of biotic assemblages to coal-mining impacts is crucial to informing regulatory and reclamation actions. However, attributing biotic patterns to specific stressors is difficult given the dearth of preimpact studies and prevalence of confounding factors. Analysing species distributions and abundances, especially stratified by species traits, provides insights into how assemblage composition shifts occur. We evaluated stream habitats and fish assemblages along a mining intensity gradient in 83 headwater (2nd- and 3rd-order) streams of the upper Clinch and Powell river basins in Virginia. Our multivariate gradient (MINE.PC1) was based on percentages of watershed area covered by surface mine, underground mine and valley fill to represent spatial variance in mining intensity. MINE.PC1 was positively correlated with conductivity and percentage of substrate as cobble. Forty fish-assemblage metrics were analysed via boosted regression trees to assess assemblage responses to mining intensity, while accounting for environmental variation and spatial structure among sites. Conductivity and MINE.PC1 were strongly negatively related to occurrences of Fantail Darter ( Etheostoma flabellare ) and sculpin ( Cottus ) spp. Several taxonomic, trophic and reproductive metrics of assemblage composition responded strongly to mining intensity or its instream correlates. For example, coal mining favoured omnivore-herbivores, but inhibited invertivores, simple lithophils and nonsimple nonlithophils. We revealed distinct negative and positive responses to mining-related stressors, which suggest changes to macroinvertebrate prey availability and/or contaminant loads contribute to fish extirpations in coalfield streams. Future assessments of mining impacts on fish assemblages could be more instructive by including characterisations of physicochemical stressors and regionally calibrated biotic metrics with demonstrated sensitivity to mining.

Virginia↗

USGS2013

Relationships between nutrient enrichment, pleurocerid snail density and trematode infection rate in streams

Summary 1. Nutrient enrichment is a widespread environmental problem in freshwater ecosystems. Eutrophic conditions caused by nutrient enrichment may result in a higher prevalence of infection by trematode parasites in host populations, due to greater resource availability for the molluscan first intermediate hosts. 2. This study examined relationships among land use, environmental variables indicating eutrophication, population density of the pleurocerid snail, Leptoxis carinata, and trematode infections. Fifteen study sites were located in streams within the Shenandoah River catchment (Virginia, U.S.A.), where widespread nutrient enrichment has occurred. 3. Snail population density had a weak positive relationship with stream water nutrient concentration. Snail population density also increased as human activities within stream catchments increased, but density did not continue to increase in catchments where anthropogenic disturbance was greatest. 4. Cercariae from five families of trematodes were identified in L. carinata, and infection rate was generally low (<10%). Neither total infection rate nor the infection rate of individual trematode types showed a positive relationship with snail population density, nutrients or land use. 5. There were statistically significant but weak relationships between the prevalence of infection by two trematode families and physical and biological variables. The prevalence of Notocotylidae was positively related to water depth, which may be related to habitat use by definitive hosts. Prevalence of Opecoelidae had a negative relationship with orthophosphate concentration and a polynomial relationship with chlorophyll a concentration. Transmission of Opecoelid trematodes between hosts may be inhibited by eutrophic conditions. 6. Leptoxis carinata appears to be a useful species for monitoring the biological effects of eutrophication and investigating trematode transmission dynamics in lotic systems.

Virginia↗

USGS2012

Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams

Application of manures from animal feeding operations (AFOs) as fertilizer on agricultural land can introduce nutrients and hormones (e.g. estrogens) to streams. A landscape-scale study was conducted in the Shenandoah River watershed (Virginia, USA) in order to assess the relationship between densities of AFOs in watersheds of agricultural streams and in-stream nutrient concentrations and estrogenic activity. The effect of wastewater treatment plants (WWTPs) on nutrients and estrogenic activity was also evaluated. During periods of high and low flow, dissolved inorganic nitrogen (DIN) and orthophosphate (PO4-P) concentrations were analyzed and estrogens/estrogenic compounds were extracted and quantified as17β-estradiol equivalents (E2Eq) using a bioluminescent yeast estrogen screen. Estrogenic activity was measurable in the majority of collected samples, and 20% had E2Eq concentrations > 1 ng/L. Relatively high concentrations of DIN (> 1000 μg/L) were also frequently detected. During all sampling periods, there were strong relationships between watershed densities of AFOs and in-stream concentrations of DIN (R2 = 0.56–0.81) and E2Eq (R2 = 0.39–0.75). Relationships between watershed densities of AFOs and PO4-P were weaker, but were also significant (R2 = 0.27–0.57). When combined with the effect of watershed AFO density, streams receiving WWTP effluent had higher concentrations of PO4-P than streams without WWTP discharges, and PO4-P was the only analyte with a consistent relationship to WWTPs. The results of this study suggest that as the watershed density of AFOs increases, there is a proportional increase in the potential for nonpoint source pollution of agricultural streams and their receiving waters by nutrients, particularly DIN, and compounds that can cause endocrine disruption in aquatic organisms.

Science of the Total Environment↗