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At least 37 records · Page 2Linked to original sources
USGS2007

Potential ecotoxicological significance of elevated concentrations of strontium in eggshells of passerine birds

We investigated the occurrence and potential ecotoxicological significance of elevated concentrations of strontium (Sr) in eggshells of nine passerine birds from four regions in Arizona. Concentrations of Sr in eggshells ranged from 70 to 1360 µg g −1 dry weight (overall mean = 684 ± 345 SD µg g −1 dw) for the four regions. 23% of the eggshells had Sr concentrations greater than 1000 µg g −1 dw. To our knowledge, these are among the highest levels of Sr that have been reported in bird eggshells in North America. Of the nine species, Brown-headed Cowbirds ( Molothrus ater ) had the greatest concentrations of Sr. There was a significant positive correlation between Sr and calcium (Ca), and between barium (Ba) and Ca. Ca, Sr, and Ba interact with each other and can exert similar chemical and pharmacological effects. Mean ( n ≥ 3) eggshell∶egg ratios for Sr varied with species and ranged from 6.1∶1 to 40.2∶1; ratios for individual eggs reached 92.7∶1. Mean Sr/Ca values ranged from 1.3 × 10 −3 to 3.0 × 10 −3 and mean eggshell thickness ranged from 83 ± 6 to 120 ± 9 µm for all species. Eggshell thickness was not significantly correlated with Sr for any species but tended to increase with Sr concentrations. We postulate that high concentrations of Sr in the shell could affect later-stage embryos by possible interference with Ca metabolism and bone growth, resulting in reduced hatching success and potential minor beak deformities.

Arizona↗
USGS2001

Ecotoxicology of Wild Mammals

An international group of 32 scientists has critically reviewed the scientific literature on exposure and effects of environmental contaminants in wild mammals. The underlying theme of this text is encompassed by the following four questions: What exactly do we know about environmental contaminants in mammals? What are the commonalities and differences between mammal orders/species in the effects that contaminants have? How and to what degree of accuracy can we predict the adverse effects of environmental contaminants on mammalian wildlife? How significant are contaminant insults compared with other density-independent and -dependent factors such as habitat loss, climatic factors and disease? The book is organized three topical sections including introductory chapters that provide a background on environmental contaminants and the mammalian orders, eight taxonomic chapters discussing all aspects of the exposure to and effects of contaminants in mammalian orders, and four thematic chapters that review and discuss generic issues including biomarkers, prediction and extrapolation of exposure and effects, hazard and risk assessment, and the relative significance of contaminants on mammals compared with other commonly encountered stressors. A final a summary chapter identifies phylogenetic trends, critical data gaps, and overarching research needs. Although the absolute number of toxicological studies in domesticated and wild mammals eclipses that wildlife species, a detailed examination of our knowledge base reveals that information for 'wild' birds is actually greater than that for 'wild' mammals. Of the various mammalian taxa, ecotoxicological data is most noticeably lacking for marsupials and monotremes. In contrast, rodents (comprising 43% of all mammal species) have been studied extensively, despite evidence of their tolerance to some organochlorine compounds, rodenticides, and even radionuclides. Mammalian species at greatest risk of exposure include those that consume a high percentage of their body weight on a daily basis. Aquatic mammals tend to bioaccumulate tremendous burdens of lipophilic contaminants, although storage in their fat depots may actually limit toxicity. Carnivores appear to be more sensitive to adverse effects of environmental contaminants than herbivores. Remarkably few of the thousands of compounds manufactured worldwide have been toxicologically evaluated in wild mammals, and concentrations of even fewer have been monitored in tissues.

Ecological & Environmental Toxicology Series.↗
USGS1995

Making sense of soil ecotoxicology

The toxicity of pesticides and environmental contaminants to soil organisms has been measured in studies on earthworms, 1 soil arthropods, 3-6 soil microorganisms, 7 and other soil organisms. 8 Toxicity data on earthworms produced in the pesticide registration procedure required by the OECD (Organization for economic cooperation and Development) will provide data on many additional chemicals. 9 Deciding how to use the data generated is troublesome. In 1965, Edwards 10 suggested that the effects of soil insecticides on soils may remain long after the pesticides have disappeared, and that it was clear that pesticides could drastically change the populations of soil organisms; Edwards noted, however, that the effects did not seem to be serious when compared with the benefits to crop production of using pesticides. Since 1965, many studies have been conducted on changes in soil ecosystems caused by environmental contaminants, but we still know little about what the toxicity to particular groups of soil organisms means to the functioning of the soil ecosystem. the problem was illustrated in discussions at the International Conference on Earthworm Ecotoxicology in Sheffield, England, in 1991. there was general agreement that earthworms ahould be taken into account when evaluating pesticides. However, it was unclear what level of reduction in earthworm populations would reduce soil quality or crop yeild. Because populations of earthworms naturally fluctuate greatly even in the absence of pesticides, and because some soils are fertile without any earthworms, it is difficult to equate their population decreases with damage to the soil ecosystem. Broadbent and Tomlin found that the insecticide carbofuran caused fluctuations in the populations of some microarthropods in a cornfield but, in comparing the effects to those of cultivation or adding compost, they concluded that it was unlikely that litter decomposition was significantly affected. 3

Book chapter↗
USGS1997

Ecotoxicology of aluminum to fish and wildlife

The toxicity of aluminum has been studied extensively in fish, less so in invertebrates, amphibians, and birds, and not at all in reptiles and free-ranging mammals. For aquatic organisms, Al bioavailability and toxicity are intimately related to ambient pH; changes in ambient acidity may affect Al solubility, dissolved Al speciation, and organism sensitivity to Al. At moderate acidity (pH 5.5 to 7.0), fish and invertebrates may be stressed due to Al adsorption onto gill surfaces and subsequent asphyxiation. At pH 4.5 to 5.5, Al can impair ion regulation and augment the toxicity of H+. At lower pH, elevated Al can temporarily ameliorate the toxic effects of acidity by competing for binding sites with H+. Aluminum toxicity in aquatic environments is further affected by the concentration of ligands such as dissolved organic matter, fluoride, or sulfate, and of other cations such as Ca and Mg which compete for cellular binding sites. Although risk of Al toxicity is often based on a model of free-ion (Al3+) activity, recent evidence suggests that factors determining Al toxicity may be more complex. In general, aquatic invertebrates are less sensitive to Al toxicity and acidity than fish; thus acidified, Al-rich waters may actually reduce predation pressure. Fish may be affected by asphyxiation at moderate acidic conditions or electrolyte imbalances at lower pH. In amphibians, embryos and young larvae are typically more sensitive than older larvae. Early breeding amphibians, which lay eggs in ephemeral ponds and streams subject to spring runoff, are most at risk from Al and acidification; those that breed later in the year in lakes or rivers are least vulnerable. Birds and mammals are most likely exposed through dietary ingestion of soil or Al-contaminated foods. Concentrations > 1000 mg.kg-1 in food may be toxic to young birds and mammals. Clinical signs in these animals are consistent with rickets because Al precipitates with P in the gut. Suggestions for additional research on the ecotoxicology of Al to wild animals are provided.

Book chapter↗
USGS2000

Ecotoxicology of wild mammals

An international group of 32 scientists has critically reviewed the scientific literature on exposure and effects of environmental contaminants in wild mammals. Although the absolute number of toxicological studies in domesticated and wild mammals eclipses that for birds, a detailed examination of scientific publications and databases reveal that information for 'wild' birds is actually greater than that for 'wild' mammals. Of the various taxa of mammals, ecotoxicological data is most noticeably lacking for marsupials and monotremes. In contrast, rodents (comprising 43% of all mammal species) have been studied extensively, despite evidence of their tolerance to some organochlorine compounds, rodenticides, and even radionuclides. Mammalian species at greatest risk of exposure include those that consume a high percentage of their body weight on a daily basis (e.g., shrews, moles and bats). Aquatic mammals tend to bioaccumulate tremendous burdens of lipophilic contaminants, although storage in their fat depots may actually limit toxicity. Carnivores appear to be more sensitive to adverse effects of environmental contaminants than herbivores. Remarkably few of the thousands of compounds manufactured worldwide have been toxicologically evaluated in wild mammals, and concentrations of even fewer have been monitored in tissues. Overarching research needs include: development of new exposure/effects models and better methods for estimation of species sensitivities; generation of comparative data on contaminant bioavailability, sublethal responses and detoxication mechanisms; enhanced understanding of pesticide, industrial contaminant and metal interactions; identification of endocrine disruptive contaminants and their overall ecological significance; and finally, estimating the relative contribution of environmental contamination as a factor affecting wild mammal populations.

Society of Environmental Toxicology and Chemistry,↗
USGS2010

Recent advancements in amphibian ecotoxicology

When the first edition of Ecotoxicology of Amphibians and Reptiles was published in 2000, I reviewed the state of the literature from 1972 through 1998 (Sparling et al. 2000). That review covered 11 271 contaminant citations listed in Wildlife Review and Sports Fisheries Abstracts published by the US Fish and Wildlife Service. Among its findings, only 2.7% of the cited papers were on amphibians and 1.4% on reptiles. This equated to an average annual rate of 11.5 citations for amphibians and 6 for reptiles, although the distribution of citations was not homogeneous through the years. In contrast, 61.8%, or 280, contaminant citations per year were on fish. Among the amphibian citations, most focused on effects, 23% dealt with metals, 22% with acid precipitation, and 19% with nonchlorinated pesticides. The remaining 38% covered all of the other contaminants of interest at that time. Almost all of the citations on reptiles dealt exclusively with residues, and turtles (Chelonia) were overrepresented compared to the percent of reptilian species comprised by this order. The most important categories of contaminants included metals (24%), organochlorine pesticides (23%), and polychlorinated biphenyls (PCBs) (19%), all persistent pollutants.

Book chapter↗
USGS1993

Developmental stability and its applications in ecotoxicology

Developmental stability refers to the ability of a developing organism to produce a consistent phenotype in a given environment. It provides a simple, reliable method of detecting stressed populations and monitoring their recovery. The most common measure of developmental instability, fluctuating asymmetry, assesses minor deviations from perfect bilateral symmetry in traits that are normally symmetrical. Measures of developmental instability are based upon the concept of developmental invariance. The biotest approach consists of the simultaneous analysis of developmental instability (and related physiological instability) in a variety of species.

Ecotoxicology↗
USGS2013

Ecotoxicology of organochlorine chemicals in birds of the Great Lakes

Silent Spring was fulfilled in the United States with passage of environmental legislation such as the Clean Water Act, the Federal Insecticide, Fungicide, and Rodenticide Act, and the Toxic Substance Control Act in the 1970s. Carson's writings, television interviews, and testimony before Congress alerted a nation and the world to the unintended effects of persistent, bioaccumulative chemicals on populations of fish, wildlife, and possibly humans. Her writings in the popular press brought attention to scientific findings that declines in populations of a variety of birds were directly linked to the widespread use of dichlorodiphenyltrichloroethane (DDT) in agriculture, public health, and horticulture. By the 1970s, DDT and other persistent organic pollutants (POPs) were being banned or phased out, and the intent of these regulatory acts became apparent in a number of locations across the United States, including the Great Lakes. Concentrations of DDT and its major product of transformation, dichlorodiphenylchloroethane (DDE), were decreasing in top predators, such as bald eagles (Haliaeetus leucocephalus), osprey (Pandion haliaetus), colonial waterbirds, and other fish-eating wildlife. Eggshell thinning and the associated mortality of bird embryos caused by DDE had decreased in the Great Lakes and elsewhere by the early 1980s.

Environmental Toxicology and Chemistry↗
USGS2022

Comparative behavioral ecotoxicology of Inland Silverside larvae exposed to pyrethroids across a salinity gradient

Pyrethroids, a class of commonly used insecticides, are frequently detected in aquatic environments, including estuaries. The influence that salinity has on organism physiology and the partitioning of hydrophobic chemicals, such as pyrethroids, has driven interest in how toxicity changes in saltwater compared to freshwater. Early life exposures in fish to pyrethroids cause toxicity at environmentally relevant concentrations, which can alter behavior. Behavior is a highly sensitive endpoint that influences overall organism fitness and can be used to detect toxicity of environmentally relevant concentrations of aquatic pollutants. Inland Silversides ( Menidia beryllina ), a commonly used euryhaline model fish species, were exposed from 5 days post fertilization (~1-day pre-hatch) for 96 h to six pyrethroids: bifenthrin, cyfluthrin, cyhalothrin, cypermethrin, esfenvalerate and permethrin. Exposures were conducted at three salinities relevant to brackish, estuarine habitat (0.5, 2, and 6 PSU) and across 3 concentrations, either 0.1, 1, 10, and/or 100 ng/L, plus a control. After exposure, Inland Silversides underwent a behavioral assay in which larval fish were subjected to a dark and light cycle stimuli to determine behavioral toxicity. Assessment of total distanced moved and thigmotaxis (wall hugging), used to measure hyper/hypoactivity and anxiety like behavior, respectively, demonstrate that even at the lowest concentration of 0.1 ng/L pyrethroids can induce behavioral changes at all salinities. We found that toxicity decreased as salinity increased for all pyrethroids except permethrin. Additionally, we found evidence to suggest that the relationship between log K OW and thigmotaxis is altered between the lower and highest salinities.

Science of the Total Environment↗
USGS1991

Reproductive outcomes in colonial fish-eating birds: A biomarker for developmental toxicants in Great Lakes food chains: I. Historical and ecotoxicological perspectives

Colonial fish-eating birds have been used as convenient model populations in which to study the impact of chronic exposure to complex mixtures of persistent lipophilic environmental contaminants within the Great Lakes ecosystem. To date, published reports of contaminant-induced adverse reproductive outcomes exist for six species. We briefly review the studies of the herring gull ( Larus argentatu s), Forster's tern ( Sterna forsteri ), and the double-crested cormorant ( Phalacrocorax auritus ) to illustrate the use of reproductive outcomes in fish-eating birds as a biomarkerfor developmental toxicants in Great Lakes food chains. We discuss the management implications of using various species for such purposes. We recommend that cormorants be used more extensively in biomonitoring programs to measure exposure and effects of polyhalogenated aromatic hydrocarbons and other contaminants in aquatic food chains in the Great Lakes.

Great Lakes↗
USGS2006

Toxicogenomics in regulatory ecotoxicology

Recently, we have witnessed an explosion of different genomic approaches that, through a combination of advanced biological, instrumental, and bioinformatic techniques, can yield a previously unparalleled amount of data concerning the molecular and biochemical status of organisms. Fueled partially by large, well-publicized efforts such as the Human Genome Project, genomic research has become a rapidly growing topical area in multiple biological disciplines. Since 1999, when the term “toxicogenomics” was coined to describe the application of genomics to toxicology (1), a rapid increase in publications on the topic has occurred (Figure 1). The potential utility of toxicogenomics in toxicological research and regulatory activities has been the subject of scientific discussions and, as with any new technology, has evoked a wide range of opinion (2–6).

Environmental Science & Technology↗
USGS2025

Ecotoxicological effects of crude oil to early life stage Danio rerio: A molecular, morphological and behavioral approach focused on swim bladder development

Proper development and inflation of the swim bladder is essential for swimming and foraging behavior in fish. To characterize the effects of the Brazilian oil spill that occurred between 2019 and 2020 to early life stage fish, the expression of genes involved in swim bladder development were targeted, with biochemical assays, morphology, and behavior assessed. The swim bladder was focused on due to recent findings of being a target of polycyclic aromatic hydrocarbons (PAHs) present in oil. Zebrafish ( Danio rerio ) were exposed to oil water accommodated fractions at concentrations measured following the spill, 1.12–71.8 total PAHs (μg-ΣPAHt L −1 ). Larvae exposed to 4.49 and 17.9 μg-ΣPAHt L −1 had a downregulation in swim bladder development genes hb9 , sox2 , has2 , and elovl1a at 48 hr postfertilization (hpf). Downregulation in these genes was associated with a high frequency of uninflated swim bladders at 96 and 168 hpf, with uninflated swim bladders detected in 100% of 96 to 168 hpf larvae exposed to 35.9 and 71.8 μg-ΣPAHt L −1 . Superoxide dismutase and catalase levels were inhibited in larvae exposed to 1.12 and 2.24 μg-ΣPAHt L −1 , respectively. There was an increase in glutathione-S-transferase and glutathione levels in exposed larvae. Average swimming speed and distance were reduced in larvae exposed to 1.12 μg-ΣPAHt L −1 . This suggests that complex mixtures of PAHs from crude oil can inhibit the transcription of genes involved in swim bladder tissue development and proper swim-up behavior, which may have implications for the viability and success of developing larvae, affecting recruitment.

Environmental Toxicology and Chemistry↗
USGS2010

Ecotoxicology of organic contaminants to amphibians

The effects of organic contaminants on amphibians are poorly known but of considerable interest. These contaminants include the highly toxic dioxins and furans as well as PCBs, PAHs and organochlorine pesticides. Although these compounds may have lower acute toxicity than dioxins and furans, they have been implicated in several problems associated with genotoxicity, endocrine disruption, malformations and reduced growth. There is evidence that amphibian tadpoles bioaccumulate these organic compounds and may have biological concentrating factors ranging in the hundreds. This chapter reviews what is known about the effects and concentrations of organic contaminants in amphibians and provides recommendations for further research

Book chapter↗
USGS2012

Ecotoxicology of mercury in fish and wildlife: Recent advances

A number of recent studies have documented subtle, yet potentially important effects of mercury on behavior, neurochemistry, and endocrine function in fish and wildlife at currently realistic levels of environmental exposure. Current levels of environmental methylmercury exposure are sufficient to cause significant biological impairment, both in individuals and in whole populations, in some ecosystems. Future toxicological studies on fish and wildlife will focus on linking biomarkers of methylmercury exposure and associated oxidative stress to effects on reproduction and population change; determining the genetic basis for mercury-related neurotoxic and other biological changes; determining the genetic basis for species differences in sensitivity to methylmercury; and linking toxic effects of methylmercury in individual animals to population-level changes.

Book chapter↗
USGS2011

Proactive aquatic ecotoxicological assessment of room-temperature ionic liquids

Aquatic environments are being contaminated with a myriad of anthropogenic chemicals, a problem likely to continue due to both unintentional and intentional releases. To protect valuable natural resources, novel chemicals should be shown to be environmentally safe prior to use and potential release into the environment. Such proactive assessment is currently being applied to room-temperature ionic liquids (ILs). Because most ILs are water-soluble, their effects are likely to manifest in aquatic ecosystems. Information on the impacts of ILs on numerous aquatic organisms, focused primarily on acute LC50 and EC50 endpoints, is now available, and trends in toxicity are emerging. Cation structure tends to influence IL toxicity more so than anion structure, and within a cation class, the length of alkyl chain substituents is positively correlated with toxicity. While the effects of ILs on several aquatic organisms have been studied, the challenge for aquatic toxicology is now to predict the effects of ILs in complex natural environments that often include diverse mixtures of organisms, abiotic conditions, and additional stressors. To make robust predictions about ILs will require coupling of ecologically realistic laboratory and field experiments with standard toxicity bioassays and models. Such assessments would likely discourage the development of especially toxic ILs while shifting focus to those that are more environmentally benign. Understanding the broader ecological effects of emerging chemicals, incorporating that information into predictive models, and conveying the conclusions to those who develop, regulate, and use those chemicals, should help avoid future environmental degradation.

Current Organic Chemistry↗
USGS2014

Mercury in birds of San Francisco Bay-Delta, California: trophic pathways, bioaccumulation, and ecotoxicological risk to avian reproduction

San Francisco Bay Estuary in northern California has a legacy of mercury contamination, which could reduce the health and reproductive success of waterbirds in the estuary. The goal of this study was to use an integrated field and laboratory approach to evaluate the risks of mercury exposure to birds in the estuary. We examined mercury bioaccumulation, and other contaminants of concern, in five waterbird species that depend heavily on San Francisco Bay Estuary for foraging and breeding habitat: American avocets ( Recurvirostra americana ), black-necked stilts ( Himantopus mexicanus ), Forster’s terns ( Sterna forsteri ), Caspian terns ( Hydroprogne caspia ), and surf scoters ( Melanitta perspicillata ). These species have different foraging habitats and diets that represent three distinct foraging guilds within the estuary’s food web. In this report, we provide an integrated synthesis of the primary findings from this study and results are synthesized from 54 peer-reviewed publications generated to date with other unpublished results.

California↗