Research Interests:
Research Interests:
Research Interests:
Microplastics (MPs) are globally ubiquitous in sediments and surface waters. Interactions between biota and MPs are complex and influence their fate and effects in the environment. Once MPs enter aquatic systems, they are colonized by... more
Microplastics (MPs) are globally ubiquitous in sediments and surface waters. Interactions between biota and MPs are complex and influence their fate and effects in the environment. Once MPs enter aquatic systems, they are colonized by biofilms that may form from the excretion of extracellular polymeric substances (EPS) from microalgae. Biofilm accumulation may change the density of the MPs, contributing to their transport to the sediments. Furthermore, benthic plantivores may consume biofilm laden MPs allowing them to enter the food web. Thus, it is crucial to understand the role algae plays in the vertical transport of MPs in the aquatic environment. In this study, Chlamydomonas was cultured with MPs at different concentrations (0-0.4 mg/mL), and temperatures ranging from 2.5 to 32.5 °C to understand the deposition dynamics and impacts of MPs on EPS production and algal density. Temperatures ranging up to 25 °C increased algal density and MPs deposition. However, at 32.5 °C, algal density and MPs deposition declined. The quantity of MPs also affected algal cell density and EPS production. MPs concentration from 0 to 0.4 mg/mL increased EPS production at all temperatures. Similarly, an increase in algal cell density and MPs deposition occurred when MPs concentration was raised to 0.3 mg/mL. Algal cultures exposed to 0.3-0.4 mg/mL of MPs had a decrease in algal cell density, with no corresponding decline in EPS production. At certain conditions, MPs can facilitate biofilm formation by stimulating EPS production, which can increase cell density thereby expediting MPs transport to the sediment.
Research Interests:
Research Interests: Chemistry, Animal Behavior, Environmental Chemistry, Daphnia, Medicine, and 13 moreBiological Sciences, Environmental Sciences, Wastewater, Animals, Nonylphenol, CHEMICAL SCIENCES, Phenols, Waste Water, Effluent, Physiological Stress Markers, Diazinon, Environmental Toxicology and Chemistry, and Stress Physiological
Research Interests:
Research Interests:
Dreissenids are invasive bivalves, native to water bodies of the Ponto-Caspian region of southwestern Asia. Following dispersion in Europe in the early nineteenth century, they were accidentally introduced into the Great Lakes region of... more
Dreissenids are invasive bivalves, native to water bodies of the Ponto-Caspian region of southwestern Asia. Following dispersion in Europe in the early nineteenth century, they were accidentally introduced into the Great Lakes region of North America in the 1980s and 1990s. Recently, they were discovered in the southwestern USA. Initially, Dreissena polymorpha (zebra mussel, ZM) spread more rapidly than Dreissena rostriformis bugensis (quagga mussel, QM); however, QM is becoming predominant in many areas of the Great Lakes and was the first to appear west of the Continental Divide, in Lake Mead. In Europe, as well, ZM was the first species to spread widely in western Europe from its endemic range; however, QM have recently been found in areas previously colonized only by ZM. This article reviews the dynamics of this double dreissenid invasion and considers the question: what mechanisms mediate the displacement of ZM by QM? Despite their similar appearance, QM differ from ZM in temperature and salinity tolerance, byssal thread attachment, growth, respiration rates, assimilation efficiency, enzymes such as thiaminase, depth of occurrence, and reproduction. Differences in reproduction include the depth at which reproductively active animals are found, the temperature at which spawning can be initiated, number of gametes produced, and length and timing of their annual reproductive cycle. A hypothetical role of hybrids between the species mediating species change is suggested. Future investigations of the displacement of ZM by QM should consider the role of reproductive differences (hybrids, responses to environmental chemicals, etc.) in mediating the change.
Research Interests:
Research Interests:
Research Interests:
Since their introduction to North America in the 1980s, research to develop effective control tools for invasive mussels (Dreissena polymorpha and D. rostriformis bugensis) has been ongoing across various research institutions using a... more
Since their introduction to North America in the 1980s, research to develop effective control tools for invasive mussels (Dreissena polymorpha and D. rostriformis bugensis) has been ongoing across various research institutions using a range of testing methods. Inconsistencies in experimental methods and reporting present challenges for comparing data, repeating experiments, and applying results. The Invasive Mussel Collaborative established the Toxicity Testing Work Group (TTWG) in 2019 to identify “best practices” and guide development of a standard framework for dreissenid mussel toxicity testing protocols. We reviewed the literature related to laboratory‐based dreissenid mussel toxicity tests and determined the degree to which standard guidelines have been used and their applicability to dreissenid mussel testing. We extracted detailed methodology from 99 studies from the peer‐reviewed and gray literature and conducted a separate analysis for studies using presettlement and posts...
Research Interests:
Research Interests:
Efforts to make research environments more inclusive and diverse are beneficial for the next generation of Great Lakes researchers. The global COVID-19 pandemic introduced circumstances that forced graduate programs and academic... more
Efforts to make research environments more inclusive and diverse are beneficial for the next generation of Great Lakes researchers. The global COVID-19 pandemic introduced circumstances that forced graduate programs and academic institutions to re-evaluate and promptly pivot research traditions, such as weekly seminar series, which are critical training grounds and networking opportunities for early career researchers (ECRs). While several studies have established that academics with funded grants and robust networks were better able to weather the abrupt changes in research and closures of institutions, ECRs did not. In response, both existing and novel partnerships provided a resilient network to support ECRs at an essential stage of their career development. Considering these challenges, we sought to re-frame the seminar series as a virtual collaboration for ECRs. Two interdisciplinary graduate programs, located in different countries (Windsor, Canada, and Detroit, USA) invested in a year-long partnership to deliver a virtual-only seminar series that intentionally promoted: the co-creation of protocols and co-led roles, the amplification of justice, equity, diversity and inclusion throughout all aspects of organization and representation, engagement and amplification through social media, the integration of social, scientific and cultural research disciplines, all of which collectively showcased the capacity of our ECRs to lead, organize and communicate. This approach has great potential for application across different communities to learn through collaboration and sharing, and to empower the next generation to find new ways of working together.
Research Interests:
Ecological thresholds and responses of stream benthic communities to
Research Interests:
Dreissenid mussels Dreissena bugensis (quagga mussel) and Dreissena polymorpha (zebra mussel) are prolific invasive species to the freshwaters of the United States and Western Europe. In the Great Lakes, D. polymorpha has initially... more
Dreissenid mussels Dreissena bugensis (quagga mussel) and Dreissena polymorpha (zebra mussel) are prolific invasive species to the freshwaters of the United States and Western Europe. In the Great Lakes, D. polymorpha has initially dominated the system since its invasion in the mid‐1980s; however, recently D. bugensis has displaced D. polymorpha as the dominant species. Dreissena bugensis has several competitive advantages over D. polymorpha, including greater tolerances to deeper and colder waters and lower respiration rates. Nevertheless, physiological differences between the species remain largely unknown. The oxidative stress response is a mechanism used by all organisms to mitigate environmental stress by reducing oxygen radicals in the body, and comparing this mechanism between similar species can be useful for understanding how different species compete in aquatic environments. We compared oxidative stress biomarkers (lipid peroxidation [LPO] and catalase [CAT] activity) in m...
Research Interests:
Background/Question/Methods Saginaw Bay is a eutrophic embayment of Lake Huron with excess nutrient loading from a largely agricultural watershed. Despite ongoing efforts to reduce nutrient loads, phosphorus levels remain elevated. We... more
Background/Question/Methods Saginaw Bay is a eutrophic embayment of Lake Huron with excess nutrient loading from a largely agricultural watershed. Despite ongoing efforts to reduce nutrient loads, phosphorus levels remain elevated. We assessed the potential importance of internal phosphorus loading; focusing on influences of sediment type, oxygen levels and dreissenid mussels on sediment phosphorus fluxes. Sediment cores were collected from three regions of the bay, and assessed for carbon, nutrients, porosity and bulk density. These cores were utilized in two separate incubation experiments evaluating: 1) sediment P flux under aerobic and anaerobic conditions, and 2) nutrient remineralization from mussel biodeposits when added to the surface of the cores. Results/Conclusions Anaerobic treatments exhibited significantly higher P release back to overlying waters (p < 0.05) when compared to aerobic treatments. This release was greatest in sediments collected from the depositional z...
Background/Question/Methods While invasive European earthworms belonging to the family Lumbricidae have known impacts on the temperate deciduous forests of North America, little is known about earthworms originating from other areas,... more
Background/Question/Methods While invasive European earthworms belonging to the family Lumbricidae have known impacts on the temperate deciduous forests of North America, little is known about earthworms originating from other areas, despite increasingly common reports of thriving populations. Amynthas hilgendorfi, an Asian species with established populations in North American forests, is characterized by an annual life cycle, high metabolic and growth rates, and an ability to thrive at very high densities – traits that distinguish this species from many European earthworms. We hypothesized that the ecological impacts of this species on forest soils also differ, and here we present the results of field and laboratory experiments designed to 1) evaluate the potential impacts of A. hilgendorfi on forest-floor nutrient cycling and leaf-litter decomposition, 2) compare these impacts to those of a better-understood European species, Lumbricus rubellus,and 3) test for interactive effects...
ABSTRACT Many initiatives since the early 1900s have been implemented to maintain water quality within the Great Lakes–St. Lawrence River basin. Despite these substantial efforts, emerging and re-emerging biological and chemical... more
ABSTRACT Many initiatives since the early 1900s have been implemented to maintain water quality within the Great Lakes–St. Lawrence River basin. Despite these substantial efforts, emerging and re-emerging biological and chemical contaminants continue to pose serious human, animal, and ecosystem health risks. With over 100 biological and chemical contaminants detected in the basin and over 600 persistent and bio-accumulative contaminants listed in international databases, the threat of these contaminants to the basin is immense. This article discusses examples of legacy and emerging contaminants and their interactions with other drivers within the basin. A historical review of these contaminants from the past 50 years (1963 to present) has been prepared, as well as a synthesis of their current state. From this information and based on local and global initiatives and reports, three future scenarios for contaminants have been described projecting to the next 50 years (present to 2063), which are categorized as Status Quo, Utopian, and Dystopian. These are meant to categorize the possible range of occurrences and help decision makers prepare for various management options and improve resilience to future changes. In addition, we have highlighted some tools that are needed to effectively detect emerging contaminants in the basin. By exploring the plausible future scenarios of contaminants in the basin, we aim to highlight the need for bi-national agreements and initiatives to be developed and extended, both in time and scope, to restore and protect the basin and encourage ecosystem health.
Research Interests:
Research Interests:
Research Interests:
Research Interests: Ecotoxicology, Biology, Daphnia, Medicine, Biological Sciences, and 15 moreInsecticides, Environmental Sciences, Nicotine, Animals, Bioassay, Ecotoxicity, Cholinesterase inhibitors, CHEMICAL SCIENCES, Daphnia Magna, Chlorpyrifos, Imidazoles, Environmental Toxicology and Chemistry, Acute Toxicity, Biological Assay, and Imidacloprid
Research Interests: Environmental Science, Environmental Chemistry, Daphnia, Medicine, Biological Sciences, and 15 moreLakes, Environmental Sciences, Humans, Animals, Plankton, Michigan, Chironomidae, Polychlorinated Biphenyl, CHEMICAL SCIENCES, Adult, Environmental Toxicology and Chemistry, Invertebrate, Food Chain, Geologic Sediments, and Dreissena
Research Interests: Environmental Science, Bioaccumulation, Environmental Monitoring, Environmental Chemistry, Medicine, and 15 moreChiroptera, Multidisciplinary, Sewage sludge, Bat, Endocrine disruptors, Animals, Sewage, Larva, Diptera, Sewage Treatment, Effluent, Endocrine Disruptors, Invertebrate, Food Chain, and Aminophenols
Summary Natural variation in the structure and function of aquatic communities along environmental or spatiotemporal gradients can influence how systems respond to biotic and abiotic disturbances. Although these context‐dependent... more
Summary Natural variation in the structure and function of aquatic communities along environmental or spatiotemporal gradients can influence how systems respond to biotic and abiotic disturbances. Although these context‐dependent responses are a well‐established element of basic ecology, they have received little attention from an ecotoxicological perspective. As the scope of freshwater bioassessment expands from single catchments to broad‐scale, regional surveys, it has become apparent that community responses to contaminants can vary significantly among locations. This variability is generally considered a nuisance and an impediment to recognising ecological patterns; however, natural spatiotemporal variation in communities also provides opportunities to test hypotheses about context‐dependent responses to contaminants in aquatic ecosystems. This study presents three examples of context‐dependent responses of benthic stream communities to contaminants. We show how longitudinal var...
Research Interests:
Daphnia (Crustacea) are extensively used as model organisms in ecotoxicology; however, little is known regarding their endocrine system. This study examines Daphnia vulnerability to vertebrate hormones. Twelve natural or synthetic... more
Daphnia (Crustacea) are extensively used as model organisms in ecotoxicology; however, little is known regarding their endocrine system. This study examines Daphnia vulnerability to vertebrate hormones. Twelve natural or synthetic vertebrate hormones were screened for activity on developmental and reproductive processes in Daphnia magna. Natural hormones tested included: β‐estradiol, gonadotropin, hydrocortisone, insulin, melatonin, progesterone, somatostatin, testosterone, and thyroxine at concentrations ranging from 1 to 100 μg/L. Synthetic hormones tested included diethylstilbestrol (estrogenic), R‐1881 (androgen), and ICI‐182,780 (antiestrogen); all hormones were screened with a 6‐d assay. Additionally, progesterone, insulin, testosterone, and thyroxine were screened for 25 d. Diethylstilbestrol decreased D. magna growth rate while thyroxine increased it. Short‐term testosterone exposure reduced D. magna fecundity; however, long‐term exposure did not, potentially indicating test...
Research Interests: Endocrinology, Environmental Toxicology, Reproduction, Biology, Daphnia, and 15 moreMedicine, Biological Sciences, Environmental Sciences, Progesterone, Internal Medicine, Insulin, Female, Animals, Hormones, Sex Determination, CHEMICAL SCIENCES, Hormone, Sex Differentiation, Daphnia Magna, and Diethylstilbestrol
Research Interests:
The temporal expansion of harmful algal blooms, primarily associated with cyanobacteria, may impact aquatic organisms at vulnerable life‐history stages. Broadcast spawning species release gametes into the water column for external... more
The temporal expansion of harmful algal blooms, primarily associated with cyanobacteria, may impact aquatic organisms at vulnerable life‐history stages. Broadcast spawning species release gametes into the water column for external fertilization, directly exposing sperm to potential aquatic stressors. To determine if cyanobacteria can disrupt reproduction in freshwater broadcast spawners, we evaluated sublethal effects of cyanobacteria exposure on quagga mussel (Dreissena rostriformis bugensis) sperm. In laboratory studies, sperm were collected after inducing mussels to spawn using serotonin and exposed to 11 cultures of cyanobacteria including Anabaena flos‐aquae, Aphanizomenon flos‐aquae, Dolichospermum lemmermannii, Gloeotrichia echinulata, 5 cultures of Microcystis aeruginosa, M. wesenbergii, and Planktothrix suspensa. Sperm motility, using endpoints of cumulative distance traveled and mean velocity, was calculated for a minimum of 10 individual sperm using a novel optical biotra...
Research Interests:
A traditional method of enumerating Clostridium perfringens using membrane filtration (MF) as an indicator of fecal contamination was compared to recently developed rapid method using Rapid Fung Double Tube (RFDT) in an evaluation to... more
A traditional method of enumerating Clostridium perfringens using membrane filtration (MF) as an indicator of fecal contamination was compared to recently developed rapid method using Rapid Fung Double Tube (RFDT) in an evaluation to characterize the extent of sewage contamination in sediments of the Great Lakes. Evaluation of these two methods included determining C. perfringens concentrations and recovery efficiencies from sewage, sewage-spiked sediments, and water (surface and bottom) and sediment samples collected from two Great Lakes. The RFDT method proved to be a superior method for identifying C. perfringens in lake sediments compared to MF, as it had higher recovery efficiency and was more rapid, reliable, simple, and effective. This study provides biological evidence of the long-term deposition and movement of sewage particulates in the Great Lakes environment and demonstrates the potential usefulness of C. perfringens as a tracer for sewage contamination using a reliable ...
Research Interests:
Background/Question/Methods Dreissena polymorpha (zebra mussel) was the first dreissenid mussel to establish in Saginaw Bay, and the only dreissenid species found in the bay between 1990 and 1996. Following this time period the closely... more
Background/Question/Methods Dreissena polymorpha (zebra mussel) was the first dreissenid mussel to establish in Saginaw Bay, and the only dreissenid species found in the bay between 1990 and 1996. Following this time period the closely related D. bugensis (quagga mussel) progressively became the dominant Dreissenid mussel in Saginaw Bay. Previous studies document the impacts of zebra mussels on the phytoplankton community during the initial years of the invasion; however, little information exists on the changes in the phytoplankton community since the species shift towards quagga mussels. We document the recent changes (2008-2010) in phytoplankton community structure following the initial zebra mussel invasion (1990-1996) using a combination of indicators including chlorophyll a, phytoplankton identifications and biovolumes, and microcystin toxin concentrations. Results/Conclusions The phytoplankton community in Saginaw Bay maintains a diverse fauna heavily dominated by diatoms. Ho...
Monitoring recreational waters for fecal contamination is an important responsibility of water resource management agencies throughout the world, yet fecal indicator bacteria (FIB)-based recreational water quality assessments rarely... more
Monitoring recreational waters for fecal contamination is an important responsibility of water resource management agencies throughout the world, yet fecal indicator bacteria (FIB)-based recreational water quality assessments rarely distinguish between analytical, spatial, and temporal variability. To address this gap in water resources research and management protocol, we compare two methods for quantifying FIB concentration variability at a frequently-used beach on Lake Huron (Michigan, USA). The first method calculates differences between most probable number (MPN) and colony-forming unit (CFU) values derived from conventional analysis procedures. The second method uses the &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;raw data&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; from these analysis procedures in a Bayesian hierarchical model to explicitly acknowledge analytical variability and subsequently infer the relative significance of the effect of sampling location and time on in situ FIB concentrations. Results of the Bayesian analysis indicate that in situ FIB concentrations do not vary significantly over small spatial and temporal scales, and that observed differences in MPN and CFU values over these same spatial and temporal scales are due almost entirely to intrinsic variability introduced by laboratory analysis procedures. Our findings underscore potential opportunities for incorporating Bayesian statistical models directly into routine recreational water quality assessments and for advancing the state of the art in methods for protecting humans from waterborne disease.
Research Interests:
Hazard quotients are commonly used with sediment quality guidelines (typically the probable effect concentration, PEC) to interpret site-specific sediment quality and potential toxicity to benthic communities. Methods to combine hazard... more
Hazard quotients are commonly used with sediment quality guidelines (typically the probable effect concentration, PEC) to interpret site-specific sediment quality and potential toxicity to benthic communities. Methods to combine hazard quotients across pollutants into a single multi-chemical hazard score are generally non-standardized. This study contrasted three multi-chemical hazard score approaches, generated as the sum (sumPEC), average (avgPEC) and weighted average hazard quotient (wtavgPEC) for 13 priority chemicals in the Detroit River, to predict chironomid abundance in sediments of appropriate habitat. In addition, a novel hazard quotient approach (HZD), that uses both threshold effect and probable effect sediment quality guidelines and an assumed sigmoidal toxicity distribution, was developed to provide an alternative summed hazard score and compared with the above hazard indices. Multivariate analyses were used to define sediment habitat types and delineate habitats that ...
Research Interests:
Research Interests:
The Great Lakes form a natural barrier to raptor migration. Thermals, or pockets of rising heat, provide buoyancy to raptors and vultures that allow them to soar for hours without flapping their wings. These thermals disappear over open... more
The Great Lakes form a natural barrier to raptor migration. Thermals, or pockets of rising heat, provide buoyancy to raptors and vultures that allow them to soar for hours without flapping their wings. These thermals disappear over open water, thus requiring raptors to avoid open-water crossings as much as possible. Migrating raptors from Canada are forced to pass to the west or east of the Great Lakes before heading south across the US to their wintering grounds in Mexico, Central and South America. For those birds traveling to the east around the Great Lakes, the region of Essex, ON and Gibraltar, MI hosts some of the largest flights of raptors north of the Mexican border. Thanks to the volunteer efforts of dedicated hawk watchers, The Detroit River Hawk Watch has become recognized as one of the top hawk watch sites in North America. With annual fall counts of almost 130,000 raptors the annual fall migration through the Gibraltar, MI hawk site is highlighted by spectacular kettles...
Research Interests:
Urban settings are increasingly faced with challenges across natural and engineered environmental systems, threatening the sustainability of urban centers where >50% of the world's population resides. The pressures of aging... more
Urban settings are increasingly faced with challenges across natural and engineered environmental systems, threatening the sustainability of urban centers where >50% of the world's population resides. The pressures of aging infrastructure, water and air pollution, and environmental justice exemplify the growing need for urban professionals to employ complex scientific reasoning across disciplines where they can effectively address the multi-faceted issues of urban sustainability. Here we present an innovative model for preparing the next generation of public, private, and academic leaders to address complex problems in urban sustainability. Specifically, we outline the design and implementation of an integrated, adaptable graduate training program, with the goals of science leadership, curriculum relevancy, community impact, broader applicability, recruitment into science, technology, engineering and mathematics (STEM) programs and careers, and program sustainability. This pr...
Research Interests:
Consumption guidelines are a common way of improving conscious consumption behaviors in areas where game fish are known to contain contaminants. However, guideline information can be difficult to distribute, and effectiveness difficult to... more
Consumption guidelines are a common way of improving conscious consumption behaviors in areas where game fish are known to contain contaminants. However, guideline information can be difficult to distribute, and effectiveness difficult to measure. To increase the distribution and effectiveness of guideline information for the Detroit River, an educational campaign was launched in 2010, which included distribution of pamphlets with consumption information, posting of permanent signs at popular fishing locations, and hiring River Walkers to personally communicate with anglers. In 2013 and 2015, we conducted in-person surveys of active shoreline anglers to determine the effectiveness of education and outreach efforts. Results from the survey indicated that 55% of anglers were aware of the guidelines in 2013, and by 2015 36% had communicated the information to family or friends. However, anglers were often unwilling to reduce consumption of popular game species, despite high contaminant...
Research Interests:
Research Interests:
Research Interests:
Consumption guidelines are a common way to improve conscious consumption behaviors in areas where game fish are known to contain contaminants. However, guideline information can be difficult to distribute, and effectiveness difficult to... more
Consumption guidelines are a common way to improve conscious consumption behaviors in areas where game fish are known to contain contaminants. However, guideline information can be difficult to distribute, and effectiveness difficult to measure. To increase the distribution and effectiveness of guideline information for the Detroit River, an educational campaign was launched in 2010, which included distribution of pamphlets with consumption information, posting of permanent signs at popular fishing locations, and hiring River Walkers to personally communicate with anglers. In 2013 and 2015, we conducted in-person surveys of active shoreline anglers to determine the effectiveness of education and outreach efforts. Results from the survey indicated that 55% of anglers were aware of the guidelines in 2013, and by 2015 36% had communicated the information to family or friends. However, anglers were often unwilling to reduce consumption of popular game species, despite high contaminant l...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Photocopy. Thesis (Ph. D.)--University of Wisconsin--Madison, 2002. Includes bibliographical references.
Research Interests:
Research Interests:
Management of invasive species has increasingly emphasized the importance of early detection and rapid response (EDRR) programs in limiting introductions, establishment, and impacts. These programs require an understanding of vector and... more
Management of invasive species has increasingly emphasized the importance of early detection and rapid response (EDRR) programs in limiting introductions, establishment, and impacts. These programs require an understanding of vector and species spatial dynamics to prioritize monitoring sites and efficiently allocate resources. Yet managers often lack the empirical data necessary to make these decisions. We developed an empirical mapping tool that can facilitate development of EDRR programs through identifying high-risk locations, particularly within the recreational boating vector. We demonstrated the utility of this tool in the Great Lakes watershed. We surveyed boaters to identify trips among water bodies and to quantify behaviors associated with high likelihood of species transfer (e.g., not removing organic materials from boat trailers) during that trip. We mapped water bodies with high-risk inbound and outbound boater movements using ArcGIS. We also tested for differences in hi...
Research Interests:
Project Abstract: The purpose of this task agreement is to obtain technical assistance for help completing revisions and updates to the Greater Yellowstone Network Water Quality Standard Operating Procedures in order to include water... more
Project Abstract: The purpose of this task agreement is to obtain technical assistance for help completing revisions and updates to the Greater Yellowstone Network Water Quality Standard Operating Procedures in order to include water quality parameters intended to be monitored as part of the Integrated Water Quality Monitoring Plan. The cooperator will provide technical assistance by helping the network define
Research Interests: Data Management, Air pollution, Animal Welfare, Puerto Rico, Quality Control, and 15 moreQuality Assurance, Rare species, National Park Service, Fuel Treatment, Native Plants, Invasive Plant, National Park, Analytical Method, Ambient Temperature, Natural Resource, Plant species, Glacier National Park, Alien Plants, Annual Report, and Information System
Contaminant exposure in aqueous systems typically involve complex chemical mixtures. Given the large number of compounds present in the environment, it is critical to rapidly identify hazardous chemical interactions. This study utilizes a... more
Contaminant exposure in aqueous systems typically involve complex chemical mixtures. Given the large number of compounds present in the environment, it is critical to rapidly identify hazardous chemical interactions. This study utilizes a prototype for a novel high throughput assay to quantify behavioral changes over time to identify chemical interactions that affect toxicity. The independent and combined effects of two chemicals, diazinon (an insecticide) and 4-nonylphenol (a detergent metabolite) on the swimming behavior of the freshwater crustacean, Daphnia pulex were examined. Cumulative distance and change in direction were measured repeatedly via optical tracking over 90-minutes. Exposure to low concentrations of diazinon (0.125 to 2 µM) or 4-nonylphenol (0.25 to 4µM) elicited significant concentration- and time-dependent effects on swimming behavior. Exposure to 0.5 µM 4-nonylphenol alone did not significantly alter mean cumulative distance, but did elicit a small, significan...