WorldCat Identities

Sofield, Ruth M.

Overview
Works: 23 works in 74 publications in 1 language and 836 library holdings
Genres: Academic theses 
Roles: Author, Editor
Classifications: QH545.A1, 571.95
Publication Timeline
.
Most widely held works by Ruth M Sofield
Introduction to environmental toxicology : molecular substructures to ecological landscapes by Wayne G Landis( )

33 editions published between 2010 and 2018 in English and held by 795 WorldCat member libraries worldwide

After fifteen years and three editions, Introduction to Environmental Toxicology: Molecular Substructures to Ecological Landscapes has become a standard that defines the field of environmental toxicology, and the fourth edition is no exception. The authors take an integrated approach to environmental toxicology that emphasizes scale and context as important factors in understanding effects and management options. This edition benefits from the insight of a new author, Dr. Ruth M. Sofield, who prepared the new chapter on the fate and transport of contaminants. The relationship between structure and toxicological properties has been a major theme of this book since its inception and this new chapter expands this fundamental concept to include fate and transport. In the early chapters the use of models in science is discussed and this theme carries throughout the rest of the book
Vectoring algal toxin in marine planktonic food webs : sorting out nutritional deficiency from toxicity effects by Amy K Burgess( )

2 editions published in 2011 in English and held by 3 WorldCat member libraries worldwide

The present study determined whether increased mortality and delayed development of larval crabs fed heterotrophic prey that themselves have been fed toxin-containing algae is due to toxicity effects or nutritional deficiency. The effects on larval crabs of previous exposure to heterotrophic prey fed toxin-containing algae were examined. Effects of varying length of exposure of larvae to toxin-containing prey were also examined. The rotifer Brachionus plicatilis was used as a heterotrophic prey source for three larval crab species (Lophopanopeus bellus, Metacarcinus magister, and Glebocarcinus oregonensis). Two rotifer treatments were created, one of rotifers fed a toxin-containing alga (Alexandrium andersoni or A. fundyense); the other of rotifers fed a non-toxic, nutritionally sufficient alga (Isochrysis galbana). To distinguish between toxic and nutritional effects, groups of larvae were fed various combinations of the two rotifer types. Diet treatments included the following ratios of toxin-containing algal fed and non-toxic algal fed rotifers: 100%/0%, 75%/25%, 50%/50%, 25%/75%, and 0%/100%. Larval crabs showed no differences in feeding rates or feeding preferences for the two rotifer diets. Crab survival was lower on the 100% toxin-containing algal fed rotifer diet when compared to the 100% nontoxin- containing algae fed rotifer diet for all three crab species. In all three crab species, stage duration was also extended in larvae fed the 100% toxin-containing algal fed rotifers compared to the 100% non-toxin-containing algal fed rotifers. Increased survival and accelerated development when toxin-containing rotifers were replaced in treatments with non-toxin-containing rotifers implicates nutritional deficiency in the former diet rather than its potential toxic effects. Reduction in time of exposure to a prey source reduced survival and extended development to a greater degree in toxin-containing rotifer treatments than in non-toxincontaining diets. There was no apparent effect of prior exposure to toxin-containing prey on survival or stage duration of later larval stage exposed to the same diet. Larval crabs face an unpredictable and complex prey environment once they enter the plankton. Encounters with Harmful Algal Blooms (HAB) or heterotrophic prey that have ingested HAB species may injure larvae that have no other food source. While my research suggests that nutritional deficiency of the rotifers fed toxin-containing algae causes higher mortality rates and delayed development in the crab larvae, toxin transfer cannot be totally eliminated and a combination of the two factors is most likely causing the negative effects. If the prey environment for these larval crabs includes a nutritionally sufficient animal prey source, negative impacts (i.e. delay in stage duration and decreased survival) caused by exposure to HABs and prey that have ingested HABs can be supplemented
Illuminating whole effluent toxicity testing : ultraviolet radiation, phototoxicity, and PAH-contaminated groundwater by Jason C Fortner( )

2 editions published in 2009 in English and held by 2 WorldCat member libraries worldwide

In this study, the acute toxicity of polycyclic aromatic hydrocarbon (PAH) - contaminated groundwater to Daphnia magna and Pimephales promelas were characterized under both ambient laboratory lighting and ambient laboratory lighting supplemented with ultraviolet radiation (UVR) using USEPA Whole Effluent Toxicity (WET) test methods. Research has shown the toxicity of some PAHs to aquatic organisms increases significantly in the presence of sunlight or artificial UVR, a phenomenon known as photoactivated toxicity or phototoxicity. Based on these findings, the discharge of PAH-contaminated groundwater to surface waters may be a phototoxic hazard to aquatic organisms. Since WET tests are frequently employed to evaluate the hazards of environmental media, they may provide a standardized means to characterize the toxicity of PAH-contaminants when sunlight is present. However, despite the known interaction of UVR with PAHs, WET protocols do not require the presence of UVR during testing. Under these protocols, the USEPA recommends the use of ambient laboratory lighting (10-20 [mu]E/m2/s or 50-100 ft-c). No recommendations are made for: 1) light source spectral distribution; 2) spectral irradiance levels; 3) presence of UVR; or 4) dose of light over time. The results of phototoxicity studies suggest that the lack of specific guidance for lighting conditions may result in inaccurate estimates of in situ toxicity when photoactive PAHs are present. To evaluate the influence of lighting on groundwater toxicity, acute groundwater toxicity was characterized in this study under the following two light treatments: 1) ambient laboratory lighting; and 2) ambient laboratory lighting plus UVA (320-400 nm) and UVB (280-320 nm). The first treatment was designed to approximate WET test lighting recommendations. The second design was based on measurements of habitat-specific irradiance, and incorporated optical radiation characteristics (UVR) that were more representative of local solar conditions. Results show that the toxicity of PAH-contaminated groundwater increased significantly to D. magna under laboratory lighting supplemented with UVR. Although trends in the P. promelas results suggest greater groundwater toxicity occurred to P. promelas when UVR was present, these trends were not found to be statistically significant. Overall, the study demonstrates that: 1) PAHcontaminated field samples be phototoxic to aquatic organisms; 2) WET testing conditions can induce phototoxicity when laboratory lighting is supplemented with UVR; 3) WET tests can be used to measure the magnitude of acute phototoxic effects; and 4) current WET lighting recommendations can lead to underestimation of sample hazard when phototoxic contaminants are present. The central implication of this study is that WET test estimation of sample toxicity may be improved in some cases by incorporating habitat-specific solar characteristics into current WET testing methodology. Moreover, since this study demonstrates that WET tests can be used to evaluate phototoxic hazards, WET testing methodology may represent a more consistent approach to phototoxicity testing for phototoxicity researchers than what is currently represented in the phototoxicity literature
Non-lethal determination of heavy metals in spiny dogfish (Squalus suckleyi) spines using LA-ICP-MS by Clayton L Bailes( )

2 editions published in 2012 in English and held by 2 WorldCat member libraries worldwide

Biological structures that develop incremental growth patterns over time present a unique opportunity to study chronological aspects of the organism's chemical environment. Spiny Dogfish (Squalus suckleyi), an abundant shark species, develop two dorsal spines that exhibit this type of growth pattern. The growth patterns on these spines have been used extensively as indicators of age. However, the chronological patterns of trace metal deposits in these spines have yet to be assessed. The main goals of this study were to develop the methods for analyzing this chronology and to explore techniques to analyze these data. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is a recently developed analytical technique for studying spatially-distributed elemental compositions in solids. LA-ICP-MS was used to quantify the concentrations of zinc and strontium across the life histories of 18 Spiny Dogfish. Metal accumulation and size differed between sharks caught at two sampling locations. This method was able to chronologically relate metal deposition to age in individuals of this species
Evaluating the contribution to toxicity of weak black liquor in pulp mill effluents by Renee L Ragsdale( )

2 editions published in 2011 in English and held by 2 WorldCat member libraries worldwide

Weak black liquor (WBL) losses in pulp mills may affect effluent treatment efficiencies and may be linked to aquatic toxicity observed in final mill effluents. Best management practices (BMP) for controlling losses of WBL have been effective at reducing WBL from entering the mill effluent treatment system, but it is unclear at what level WBL may contribute to increased toxicity, or whether specific chemical compounds found in WBL may be consistently responsible. The objective of this study was to evaluate the contribution of WBL in biologically-treated bleached kraft pulp mill effluents to toxicity, and to assess effluent chemical parameters that may correlate with biological responses. Weak black liquor and untreated wastewater (as it enters the biological treatment system) were collected from four bleached kraft mills along with mill-treated effluent samples. To simulate a range of potential WBL losses, various concentrations of WBL were added to untreated wastewater from each mill and treated in bench top aerobic reactors to mimic biological treatment (biotreatment). Following laboratory biotreatment, toxicity of the resulting "simulated effluents" (as well as mill-treated effluents) were evaluated using 48-h Mytilus galloprovincialis embryo-larval development and 7-d Ceriodaphnia dubia survival and reproduction chronic toxicity tests. All effluent samples were chemically characterized for pH, color, conductivity, turbidity, total suspended solids (TSS), polyphenols, hardness, alkalinity, salinity, biochemical oxygen demand (BOD), dissolved chemical oxygen demand (DCOD), dissolved organic carbon (DOC), resin acids (RAs), and phytosterols. Correlation analysis was used to determine if there were significant correlations between: 1) WBL solids and simulated effluent chemical parameters; 2) WBL solids and chronic toxicity to M. galloprovincialis and C. dubia; 3) effluent (mill-treated and simulated) chemical parameters and chronic toxicity to M. galloprovincialis and C. dubia; and 4) between the two chronic toxicity tests. Multivariate methods including cluster analysis (hierarchical, kmeans, and non-metric Riffle) and PCA were also used to explore the data for patterns, and to identify effluent chemical parameters that might relate to WBL solids or effluent toxicity. Results were that the 48-h EC50 for M. galloprovincialis embryo-larval development appears to be a more sensitive endpoint than the 7-d C. dubia reproduction with respect to both mill-treated and simulated effluent samples. For the simulated effluent samples, color, DCOD, and polyphenols were positively correlated with WBL solids. For three out of four mills, color and polyphenols were negatively correlated with the 48-h EC50 for M. galloprovincialis embryo-larval development (i.e. as the EC50 decreased (toxicity increased) these chemical parameters increased)). For two out of four mills, DCOD was negatively correlated with the 48-h EC50 for M. galloprovincialis embryo-larval development. Significant negative correlations were also observed between the 48-h EC50 for M. galloprovincialis embryo-larval development and abietic acid (one mill out of four) and between the 48-h EC50 for M. galloprovincialis embryo-larval development conductivity (one mill out of four). None of the measured chemical parameters correlated with chronic toxicity to C. dubia. A significant negative correlation was also observed between the 48-h EC50 for M. galloprovincialis embryo-larval development, and between WBL solids and the 7-d IC25 C. dubia reproduction (i.e. as WBL solids increased the toxicity increased (as indicated by a decrease in EC50/IC25)). A correlation was not found between the two chronic toxicity tests. Consistent across all multivariate methods, simulated effluent samples appeared to group together based on mill rather than on the amount of WBL solids added
Traditional and alternative delivery methods of general chemistry labs : environmental, monetary, and pedagogical comparisons by Sarah Steely( )

2 editions published in 2012 in English and held by 2 WorldCat member libraries worldwide

The main objective of my study was to investigate and compare a traditional and alternative mode of general chemistry laboratory delivery using environmental, monetary, and curriculum comparisons. I conducted an environmental carbon footprint analysis of traditional laboratory experiments versus laboratory kit counterparts. A dollar cost assessment of the delivery modes was also calculated. Both the environmental and dollar costs were determined on a per student basis for each experiment evaluated. The results demonstrate that traditional experiments had higher carbon emissions than the kit experiments, and the kit experiments were more expensive per student than the traditional experiments when I accounted for both faculty and graduate teaching assistant instruction. My analyses were strongly influenced by the boundary conditions and assumptions used in the carbon emission and cost calculations, so the results are only valid for the specific conditions described within this thesis. A review of the literature and a content analysis of the traditional and alternative laboratory delivery methods revealed that there was no clear evidence that one form of delivery was better at delivering a laboratory experience than the other in terms of student performance on exams or course grades. Both methods were also similar in the cognitive skills required of students. While the kits did not appear to be more appropriate at delivering a laboratory experience than traditional laboratories, they may offer an alternative for students who are unable to complete chemistry requirements in a more traditional setting. The literature review also revealed that there is a critical need for peer-reviewed studies with good experimental design to compare the effectiveness of a laboratory kit experience to a traditional laboratory experience
An assessment of the phototoxicity of contaminated groundwater : using whole effluent toxicity bioassays on daphnia magna and pimephales promelas with UVR supplemented lighting by Jason C Fortner( Book )

2 editions published in 2009 in English and held by 2 WorldCat member libraries worldwide

Spatial variability of snow chemistry of high altitude glaciers in the Peruvian Andes by Lindsay K Wallis( )

2 editions published in 2016 in English and held by 2 WorldCat member libraries worldwide

Atmospheric contaminants become incorporated in glaciers through both wet and dry deposition. Some of this particulate matter can act as a source of contamination to glacial streams, leading to a concern for the chemical contamination to cause downstream toxicity to aquatic organisms and toxicity to people ingesting that water. Other portions of this particulate matter, including black carbon, can decrease the amount of light reflected off the snow, thereby contributing to increased rates of glacial melting. These issues are especially of concern to tropical glaciers, which are receding rapidly and are relied on heavily to provide drinking water in the dry season. A snow sampling campaign was conducted on the glaciers of seven mountains in the Cordillera Blanca mountain range in Peru during June-August, 2015 to determine concentrations of inorganic contaminants and black carbon in the upper layer of snow on high altitude glaciers (>5000 m.a.s.l.). Elevation did not appear to be a factor in chemical concentrations, as there were no significant linear relationships with measured analytes and elevation, with the exception of Zn on one mountain sampled. Snow samples on two of the mountains had higher As and Pb concentrations than U.S. Environmental Protection Agency (USEPA) established water quality criteria for human health. Five metals (Al, Cd, Fe, Pb, and Zn) were found to exceed the USEPA aquatic life criteria in at least one sample. The highest concentrations of black carbon and metals were found closest to a local population center and lowest were found in areas furthest from anthropogenic influences. This study also provides supporting evidence that soil/dust is a contributing source of particulate matter but not the light absorbing fraction. An initial attempt at sourcing the particulate matter in these samples was made through an examination of analyte ratios, correlations, and principal components analysis. Multivariate analysis, including hierarchical clustering on principal components, could not explain categories based solely on concentrations of light absorbing particles or distance from the closest large city in the region. The sources of contaminants in the area appears to be complicated, and further studies would provide more insight into the source and spatial distribution of particulate matter on these tropical glaciers
Emergent contaminants and effects on field-exposed chinook salmon and cutthroat trout in the Stillaguamish Watershed, WA. by Jody M Pope( )

2 editions published in 2016 in English and held by 2 WorldCat member libraries worldwide

Contaminants of emerging concern (CECs) are chemical compounds that have no regulatory standards, are recently discovered in the natural environment due to improved analytical methods, and can potentially cause adverse effects to aquatic life. More specifically, CECs affecting fish communities include endocrine disrupting chemicals (EDCs), which can produce developmental abnormalities or alter the epigenome, potentially affecting survival and reproductive success. This study assessed CEC occurrence as well as toxicological and epigenetic responses of caged, hatchery-reared Chinook salmon (Oncorhynchus tshawytscha) and field-collected, wild, resident cutthroat trout (O. clarkii) at sites representing different land uses in the Stillaguamish River watershed, Washington State. This study was comprised of two experiments over two years: the first hatchery-reared juvenile Chinook salmon were caged for 28-days and the second, wild, resident cutthroat trout were captured via electroshocking. This study analyzed presence and concentrations of CEC analytes in stream water using Polar Organic Chemical Integrative Sampler (POCIS) devices across all study sites. The study analyzed chemical contaminants in fish tissues (i.e., liver and gall bladder), as well as vitellogenin (VTG) protein in blood plasma. Gene expression was analyzed using microarray technology. Contaminants of emerging concern occurrences and concentrations were generally low, although somewhat higher at sites receiving urban or agricultural runoff or wastewater treatment effluent. Chemical analyses indicated low CEC concentrations in sampled tissue from both Chinook and cutthroat, as most analytes were not detected above reporting limits. Vitellogenin protein results revealed few measurable detections. Analysis of gene expression also suggest overall weak responses relative to controls. Overall, this study found some CEC pollution, mostly at sites influenced by urbanization, agriculture or wastewater effluent, but there was little to no indication that CECs are affecting fish health in the Stillaguamish watershed
Determining biologically available phosphorus in storm water entering Lake Whatcom, WA using the dual culture diffusion apparatus by Jonnel Deacon( )

2 editions published in 2015 in English and held by 2 WorldCat member libraries worldwide

Long term monitoring of Lake Whatcom, a large monomictic lake located near Bellingham, Washington, has indicated a decrease in water quality that resulted in excessive algae growth associated with increased phosphorus inputs. Recently, a total maximum daily load was issued to limit phosphorus inputs into the lake, with emphasis on storm water mitigation. Not all phosphorus in storm water can be used by algae; the portion that can be used is described as bioavailable, and includes both inorganic and organic forms of phosphorus. My research focused on quantifying the amount of phosphorus made available by alkaline phosphatase, an algal and bacterial enzyme that can release some of the phosphorus associated with organic and inorganic particulates. Storm water samples were collected from tributaries of Lake Whatcom and analyzed to determine the total phosphorus concentrations. The alkaline phosphatase bioavailable phosphorus concentration was determined using dual culture diffusion apparatuses, with phosphorus-starved Selenastrum capricornutum algal cultures that were separated from the storm water phosphorus source by an enzyme-permeable membrane. The total phosphorus concentrations in the storm water were reduced by 37 to 92% (median = 78%), which suggests that storm water entering Lake Whatcom contains a substantial amount of bioavailable phosphorus. Because of this, management goals should assume that all storm water entering the lake from these tributaries has an equal ability to sustain algal growth. Chlorophyll was not correlated with phosphorus reductions, suggesting that in these short-term tests, the algal cellular energy may have been focused on enzyme production to facilitate phosphorus uptake
The influence of humic acid and water hardness on the partitioning of silver ions and nanoparticles between fresh water and freshwater algae by Matthew D Ferguson( )

2 editions published in 2011 in English and held by 2 WorldCat member libraries worldwide

Silver nanoparticle (AgNP) containing products are abundant in consumer goods. If trends continue, AgNP levels will continue to rise as innovative applications continue to be realized. These nanoparticles (NPs) can enter the environment as their uses can transport them to natural waters (e.g., washing socks containing AgNPs). Research on the behavior of AgNPs and Ag+ in artificial fresh water is presented in this thesis. Specifically, their sorptive properties between fresh water and freshwater algae, Pseudokirchneriella subcapitata (Korshikov) Hindák, as a function of hardness, humic acid (HA) content, and silver type were investigated. The experimental design was modeled after a 23 factorial analysis in which each factor is varied at two levels: (1) no added HA and with HA, (2), Ag type [AgNP versus Ag+], and (3) low hardness and high hardness. The Freundlich Isotherm method was used to determine the KF partitioning constants at the varying conditions. The effects of each factor on partitioning constants were evaluated. A normal probability plot was used to determine which factors had the greatest effect. Results were that the greatest effects were caused by hardness and the interaction between hardness and HA. An increase in hardness caused a decrease in Ag sorption by an average log KF of 0.46475, whereas the interaction between hardness and HA caused an increase in Ag sorption by an average log KF of 0.40375. The other two main effects (Ag type and HA content) also had an effect on sorption. However, these main effects were not as great as that observed with hardness
Impacts of major freshwater ions on the acute toxicity and chemical behavior of silver nanoparticles by Claire A Walli( )

2 editions published in 2019 in English and held by 2 WorldCat member libraries worldwide

Silver nanoparticles (AgNPs) are increasing in presence in commercial and medical products due to their bactericidal properties and can be transported into the environment during the laundering, use, and waste of those products. Strong evidence suggests aqueous silver (Ag+) dissolved from the AgNP surface is the toxic component of AgNPs but there is no consensus on the possibility of additional nanoparticle-specific properties that elicit toxicity. Ag+ toxicity to freshwater organisms has been well studied using the Biotic Ligand Model (BLM), which describes how water quality conditions, such as the concentrations of certain freshwater ions, affect the toxicity of Ag+. Some freshwater ions also cause AgNPs to aggregate, which can reduce the surface area from which Ag+ can dissolve. The sensitivity of AgNPs to water quality conditions has made studying their toxicity challenging in part because the range of acceptable water quality conditions in standardized toxicity testing methods produces different AgNP toxicity results. This study assessed the impacts of the freshwater ions Ca2+, Na+, Cl-, and SO42- on AgNP toxicity and chemical behavior in ASTM acute Daphnia magna toxicity testing conditions. Toxicity and analytical tests were performed in experimental waters created by adding fixed concentrations of NaCl, CaCl2, and Na2SO4 to ASTM moderately hard water (MHW) in a factorial design. AgNP sedimentation was measured using UV-Vis, and particle size distribution and particle concentration were measured using the single particle ICP-MS technique. LC50s for experimental waters ranged from 53.48 - 383.52 [lower case mu]g/L. NaCl and CaCl2 reduced toxicity in comparison to MHW. The rank order for AgNP LC50s in the experimental waters was the same as the rank order that the BLM predicted for Ag+ toxicity indicating that Ag+ dissolved from the AgNP may have been responsible for some of the AgNP toxicity. However, CaCl2 reduced toxicity more than the BLM predicted should happen based on Ag+ and there was a much larger interaction effect between CaCl2 and NaCl than was predicted. CaCl2 significantly increased particle size and sedimentation rates, which was concluded to be caused by the Ca2+. An interaction effect between CaCl2 and NaCl was also observed for sedimentation, which appeared to be due to the doubled Cl- concentration. AgNP aggregation was likely responsible for the differences between the AgNP toxicity results and the predictions of the BLM supporting that the BLM is not able to completely characterize all of the factors that affect AgNP toxicity
Characterization of particulate matter accumulated on Ramalina farinacea in the Seattle area using semi-automated electron microscopy by Tor G Guddal( )

2 editions published in 2018 in English and held by 2 WorldCat member libraries worldwide

Semi-automated scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) can be used to determine the size and composition of filtered particulate matter (PM). This information is valuable for determining the identity and contribution of overlapping air emissions. One limitation of this method is the cost of filtering PM at enough locations to give meaningful spatial data. To address this limitation, I developed an exploratory method to collect PM using Ramalina farinacea for semi-automated SEM analysis as a component of lichen biomonitoring studies. I applied this method as a proof of concept in the Seattle area to better understand trends in regional urban dust. To do this, bags of lichen were transplanted to 9 locations in the Duwamish Valley and adjacent uplands for 3 months between September and December, 2017. Some of these locations were arranged close to major industrial sources of airborne metals, which we hypothesized would contribute to the PM observed on the lichens alongside the regional background signature of particulate emissions. Upon collection, PM deposition on the lichen was characterized using SEM with EDS. A total of 18,581 particles were identified and analyzed using the PACLA for Oxford two-stage classifier. My findings suggest that R. farinacea are an effective tool for collecting PM and show the greatest proportion of anthropogenic-specific particles on lichens adjacent to Interstate 5. Furthermore, the spatial trends of PM between locations suggest that fugitive dust controls such as green walls and green spaces may be more effective than point source controls at further reducing exposure to harmful dust in the Seattle area
Changes in water chemistry and biological communities associated with metal mining in streams in the North Cascades by Brooke G Bannerman( )

2 editions published in 2017 in English and held by 2 WorldCat member libraries worldwide

Hard rock and placer mining have been occurring throughout the mountains in the northern portion of Washington State since the late-1800s. As a result, aquatic ecosystems in this region are susceptible to the physical, chemical and biological changes that result from mining activities. These alterations, which include changes in water chemistry, habitat modifications, and reduction or contamination of food sources, can adversely impact aquatic communities of periphyton, benthic macroinvertebrates and fish. To evaluate changes in water chemistry and biological communities in two regions with extensive mining histories, the Ruby Creek watershed and Upper Skagit River watershed, I analyzed metals in grab samples of surface water, on Stabilized Liquid Membrane Devices (SLMDs) which passively sample metals in surface waters over time, and in periphyton. Metals were present in the water and benthos, and site-specific and temporal differences in the kinds and quantities of metals were linked to locations of hard rock and placer mining activities. Metal concentrations in surface waters differed between sites upstream and downstream of mining depending on different times when mining was or was not occurring. Metal concentrations in surface waters at some sites in the Ruby Creek watershed were high enough to be capable of adversely affecting aquatic organisms over time. Metals that were present in streams were not always detected in grab samples, but their presence was confirmed by SLMDs and periphyton. Clustering analyses of both SLMDs and periphyton each distinguished two different groups of samples, samples collected downstream of placer mining (SLMDs) and samples collected downstream of hard rock mining (periphyton). The accumulation of metals in periphyton indicated these communities could be a concentrated source of toxic metals to primary consumers, such as small aquatic insects, and may pass to other aquatic organisms at higher trophic levels through dietary exposures
Effects of heavy metals on benthic macroinvertebrates in the Cordillera Blanca, Peru by George L Burgess( Book )

2 editions published in 2015 in English and held by 2 WorldCat member libraries worldwide

Glacial retreat as a result of global climate change is causing ongoing alterations in the hydrogeochemistry of streams in the glacial foreland of the Cordillera Blanca mountain range in Ancash, Peru. Changes in water chemistry include increased concentrations of toxic metals and decreased pH, which have the potential to affect the structure of benthic macroinvertebrate communities in impacted streams. This study measured physical-chemical water quality parameters, metal concentrations, and macroinvertebrate abundances at 29 sample reaches throughout seven valleys located in Huascaran National Park. The relationships of invertebrate abundances and metrics of community structure to water quality parameters, including metal concentrations, were analyzed by non-parametric correlation. Several sensitive local taxa were identified, including the Baetidae, Heptageniidae, Helodidae, and Tabanidae families, as well as the Oligochaeta. In addition, a regional source analysis was conducted for toxic metals, which found six of seven consistently detected metals share a common source. Finally, an analysis of the cumulative criterion unit (CCU) was performed; CCU, an approach to metal mixture toxicity, can be calculated either on the basis of total or dissolved metals. Previous studies in the region used total metal concentrations. Invertebrate abundances and metrics correlated about as well or slightly better, in general, with CCU computed on the basis of dissolved metals as they did with CCU computed with total metals
A multivariate analysis of the relationship between the water quality conditions and algal species composition of six mountain lakes in the North Cascades, WA, USA by Michael P Lawlor( )

2 editions published in 2019 in English and held by 2 WorldCat member libraries worldwide

The objective of my study was to characterize the water quality conditions and algal species composition of six mountain lakes in the North Cascades of Washington, USA. Exploratory data analysis examined water quality conditions and algal species composition separately, then determined if they were related. The lakes exhibited median temperatures from 13.3 °C to 20.8 °C, had nitrate and soluble reactive phosphate concentrations below 100 [lowercase mu]g/L and 6 [lowercase mu]g/L, respectively, were slightly acidic (pH 5.1-6.9), and had median dissolved oxygen concentrations ranging from 6.7 mg/L to 10.6 mg/L. Over 340 non-diatom algal taxa were identified. Algal species richness was positively correlated with water temperature ([lowercase tau] = 0.353, p-value <0.05), and peak richness occurred between the middle of August and beginning of September. Desmids had the greatest richness of any major algal group, with 181 unique taxa. Many of the desmid taxa identified are ecologically sensitive. Hierarchical clustering separated the lakes into the same three distinct groups for both the water quality and algal species composition data, suggesting they are associated with one another. The observed relationship between algal species composition and water quality conditions, and the presence of many sensitive algal taxa indicates that algal biomonitoring would be an effective tool for detecting changes in water quality conditions of lakes in the North Cascades. This study expands upon the water quality and algal monitoring of mountain lakes in the North Cascades, which contributes to the larger effort to use mountain lakes to monitor changing climatic conditions
Water quality and algal diversity of ten lakes along the Mountain Loop Highway, Washington by Katy Pfannenstein( )

2 editions published in 2016 in English and held by 2 WorldCat member libraries worldwide

The first pre- and post-wildfire charcoal quantification using peroxide-acid digestion by Melissa R. A Pingree( )

2 editions published in 2011 in English and held by 2 WorldCat member libraries worldwide

In the summer of 2002, the 200,000-ha Biscuit Wildfire consumed a portion of the 150-ha Long-Term Ecosystem Productivity (LTEP) experiment in the Siskiyou National Forest, Oregon. The wildfire burned previously established 100-year-old conifer control and thinned experimental units, which allows comparison with prescribed burn and unburned units. This research evaluates the O horizon and mineral soil charcoal, a key fire-related soil component that affects physical and chemical properties. Charcoal C was quantified by a peroxide-acid digestion method developed for forest soils. Charcoal C was 17% of the organic C for a reference Australian Vertisol soil and 9% for a German Chernozem, which are similar to published values from a dichromate digestion method. The charcoal C of the Siskiyou LTEP soils was quantified in hand-sorted charcoal from the O horizon and in the <4-mm fraction of the A (0-3 cm depth) and B1 (3-15 cm depth) mineral soil horizons. The mineral soils contained substantial amounts of charcoal C and no changes were detected as a result of prescribed or wildfire. Concentrations were 10 g charcoal C/kg in A horizon and 7 g charcoal C/kg in B1 horizon and areal masses averaged 1,860 kg charcoal C/ha in A layer soils and 5,260 kg charcoal C/ha for B1 layer soils. Charcoal C in the O layer averaged 18 kg charcoal C/ha prior to the fire and was increased by a factor of 5 by both prescribed fire and wildfire. The effect of thinning on wildfire-induced charcoal C changes was non-significant. Charcoal was formed at a rate of 0.5 - 6.0% of surface woody fuels consumed in the wildfire. Long-term soil C sequestration in the Siskiyou - LTEP soils is greatly influenced by the contribution of charcoal C, which makes up 20% of mineral soil organic C. The significant effect of recent fire on the O layer soils demonstrates the significant short-term effects of the Biscuit Wildfire and the dynamic nature of the O layer. This research reiterates the importance of wildfire and prescribed fire to soil C in a Southwestern Oregon coniferous forest ecosystem
Land use, riparian buffers, and biological stream conditions in the Puget lowlands of Washington by Colin Wahl( )

2 editions published in 2012 in English and held by 2 WorldCat member libraries worldwide

Stream conservation and restoration strategies often focus on preserving extant riparian forest and restoring riparian habitat. In the Pacific Northwest, these efforts are often directed toward restoring and maintaining habitat that supports salmon populations. Riparian restoration, though beneficial to stream habitat, may not be sufficient to restore functioning stream ecosystems in watersheds heavily altered by intensive land use. To evaluate this hypothesis, I measured the biological condition of streams affected by human activity, and compared reaches with and without limited riparian corridors. I assessed 12 streams in watersheds dominated by different land use (cultivated, developed, forested, grassland) and sampled from reaches with and without riparian forests. This study integrated invertebrate data and abiotic stream parameters collected in 2006 and water nutrients and sediment toxicity collected in 2009-2010. I calculated the percent of individuals (relative abundance) from insect orders Ephemeroptera, Plecoptera, and Trichoptera (%EPT) and assessed specific conductance, dissolved oxygen (DO), temperature, and substrate, water nutrients and sediment toxicity. Relative abundance of intolerant invertebrates was highest in watersheds that most resembled historic forested habitat. Forested watersheds averaged the highest %EPT (23.8) followed by grassland (16.1), cultivated (1.96), and developed (0.31). Riparian forests were not associated with increased %EPT in forested, cultivated or developed watersheds. However, in grassland watersheds, %EPT was ~8-fold higher in forested than non-forested reaches. High values of %EPT were associated with ostensibly good abiotic conditions (i.e., large stream substrate, low specific conductance and temperature), common in forested watersheds. Developed and cultivated watersheds did not follow this pattern. In some cases, %EPT was low despite abiotic conditions similar to forested watersheds, where %EPT was high. While water nutrients were higher in cultivated watersheds, there were no discernable patterns in sediment toxicity, and neither nutrients nor toxicity were correlated with %EPT. These results confirm that intensive land use degrades stream biological communities, and suggest that patchy forested riparian corridors are insufficient to mitigate severe, large-scale biological degradation
An investigation of acid rock drainage in glacial streams through multivariate exploratory analysis and the Biotic Ligand Model in the Cordillera Blanca, Peru by Edward W Bain( )

2 editions published in 2017 in English and held by 2 WorldCat member libraries worldwide

Water chemistry in the Cordillera Blanca, Peru, where glaciers provide crucial freshwater to the arid Andes Mountains, was characterized during the dry season (June-August), 2014. Metal concentrations, anion concentrations, and physical and chemical parameters were assessed at 94 sample sites in seven river valleys. Nonparametric multivariate exploratory statistics were used to compare sample sites. Compared to other river valleys, high metal concentrations were evident in the Quilcayhuanca valley. Water chemistry and visual signs indicated that acid rock drainage (ARD) is occurring in the Cordillera Blanca, likely due to glacial recession. Hierarchical clustering analysis was performed on the results of a principal components analysis on the chemical data. The results of these two analyses showed cobalt, manganese, and nickel were the top metals that distinguished the different clusters. In addition to the exploratory analysis, the Biotic Ligand Model (BLM) was used to predict toxicity to aquatic life based on the chemical measurements at the sampling sites. Approximately 20% of the sites had predicted toxic responses to metals and another 20% of the sites were outside of the pH tolerance range of individual species. These sites outside of the pH ranges were assumed to cause toxicity to the aquatic organisms due to hydrogen ions rather than metals. From this, the altered water quality in headwater streams in the Cordillera Blanca is predicted to be detrimental to aquatic life. The reduction in water quality makes the understanding of these headwater streams critical in efforts to mitigate the loss of crucial water resources
 
moreShow More Titles
fewerShow Fewer Titles
Audience Level
0
Audience Level
1
  Kids General Special  
Audience level: 0.37 (from 0.35 for Introducti ... to 0.73 for Vectoring ...)

Introduction to environmental toxicology : molecular substructures to ecological landscapes
Covers
Alternative Names
Sofield, Ruth

Languages
English (71)