Download or read book Effects of Chronic Pesticide Exposure on Larval Amphibians written by Shannon E. Julian and published by . This book was released on 2000 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Pesticides on Amphibians with Special Reference to the Pyrethroid Insecticide Cypermethrin written by Lindsay M. Biga and published by . This book was released on 2013 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pollution by pesticides is a ubiquitous concern for wildlife. The effects of pesticides are especially concerning in aquatic environments, which are particularly vulnerable as they have several exposure routes for the influx of chemicals. These effects are of particular concern as biodiversity loss reaches unprecedented rates. This includes recent declines of amphibian populations and loss of amphibian species. Pesticide exposure may contribute to some amphibian populations and extinctions. This dissertation explores the effects of pesticides on amphibians, with particular reference to the pyrethroid insecticide cypermethrin. I first synthesized acute toxicity data of pesticides for amphibians from the literature (Chapter 2). Using 96h LC50 values for amphibian larvae exposed to insecticides, herbicides, and fungicides, I determined that amphibian species cannot be systematically classified as sensitive or tolerant to pesticides. Rather, relative acute lethal toxicities varied among species and between chemicals and types of pesticides even within a species, indicating that no amphibian species from this analysis can represent anticipated toxic effects to all amphibians. I next examined the differences in sensitivity to cypermethrin among three developmental stages for three anuran (frog) species (Chapter 3). I experimentally exposed embryos, recently hatched larvae and larvae with limb buds to cypermethrin in the laboratory. Exposure to cypermethrin had lethal and sublethal effects on some species and stages, but not all. The Pacific treefrog (Pseudacris regilla) was the most sensitive species and the early larval stage was the most sensitive for these three species. Additionally, cypermethrin exposure induced abnormal behavior in response to prodding for some species and stages. These results indicate differences in sensitivity to cypermethrin among species of amphibians. To further understand differences in sensitivity to pesticides among amphibians, I compared how three populations of P. regilla responded to cypermethrin exposure (Chapter 4). I performed a time-to-death assay in the laboratory, exposing newly hatched larvae from each population to cypermethrin under identical conditions. All populations had high rates of mortality when exposed to cypermethrin compared to unexposed controls and populations varied in the time to death. Moreover, exposed individuals were smaller than unexposed controls. Interestingly, population sensitivity did not appear to be associated with proximity to agriculture, but rather with elevation gradient, indicating that an evolved tolerance to pesticide exposure is not the mechanism for the differences in sensitivity observed here. To investigate the effects of cypermethrin on amphibians within a community context, I studied exposure in mesocosms (Chapter 5). I set up semi-natural aquatic ponds in enclosures that contained zooplankton, phytoplankton, and periphyton along with amphibian larvae. I experimentally exposed these mesocosms to cypermethrin and measured the effects on the amphibians and the other members of the community. Cypermethrin affected the entire aquatic community, even at the lowest dose, indicating the direct and indirect deleterious effects of cypermethrin on both invertebrate and vertebrate species in an aquatic community. This dissertation provides needed data on the effects of the pyrethroid insecticide cypermethrin on amphibians and their communities. Understanding the toxicity of newer, commonly used pesticides to non-target organisms is important as conservation biologists and managers make efforts to combat future amphibian population declines which may be associated with chemicals in the environment.
Download or read book Pesticide Effects on Amphibians written by Jacob Lawrence Kerby and published by . This book was released on 2006 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Chronic Fungicide and Herbicide Exposure on Survival and Development of Amphibian Larvae written by Jan E. Ferrigan and published by . This book was released on 2001 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of an Insecticide on Amphibian Communities written by Michelle Dawn Boone and published by . This book was released on 2000 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rachel Carson's Silent Spring raised public awareness that there were ecological consequences to widespread pesticide use. Yet many of the pesticides used today are benign in comparison with the early synthetic pesticides. However, the effects of these chemicals are typically not tested on living communities. The effects of pesticides on natural community dynamics may be especially noteworthy for amphibians in light of recent concerns about amphibian declines. The main objective of my research was to determine how realistic, sublethal levels of the short-lived insecticide carbaryl may influence amphibian species that are experiencing stresses known to be important in the natural environment (e.g., competition, predation, pond drying). This research was conducted in artificial ponds (i.e., cattle tanks) and in small farm ponds to test the effects of carbaryl on amphibians. Carbaryl may serve as a model chemical for other contaminants with the same mode of action (acetyl cholinesterase inhibition: carbamates and organophosphates). I measured endpoints at metamorphosis (survival, mass, and age) to determine if exposure to carbaryl had lasting effects on tadpole development and survival. Studies in cattle tank indicated that the effects of carbaryl varied depending on the predator environment and initial larval density for some species. Interactions of carbaryl with predator and density may result in an indirect effect of carbaryl causing increased food resources through the elimination of zooplankton populations that may compete for similar resources as tadpoles; this resulted in greater survival and greater mass at metamorphosis for some species relative to individuals in control ponds. In an experiment where multiple exposures to carbaryl were applied, exposure led to higher rates of metamorphosis with the majority of metamorphs coming from high-density ponds dosed three times. This interaction suggests that exposure to carbaryl later in the larval period may have stimulated metamorphosis in high-density conditions. Because natural environments include a large range of factors typically excluded in experimental studies, we cannot assume contaminant levels that are safe in the laboratory or in mesocosms are protective of populations in the natural environment. A study in farm ponds, however, suggested that even a short-lived contaminant like carbaryl can affect amphibian species in field conditions. Carbaryl exposure positively influenced survival with approximately twice as many individuals leaving carbaryl treated ponds than control ponds. Our results indicate that differences in biotic conditions influenced the potency of carbaryl and that even low concentrations induce changes that may alter community dynamics in ways not predicted from single-factor, laboratory-based studies. Additionally, our results suggest that even in realistic conditions where predatory and competitive conditions may be strong, contaminants can still alter population dynamics.
Download or read book OECD Guidelines for the Testing of Chemicals Section 2 Test No 231 Amphibian Metamorphosis Assay written by OECD and published by OECD Publishing. This book was released on 2009-09-08 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Test Guideline describes an amphibian metamorphosis assay intended to screen substances which may interfere with the normal functioning of the hypothalamo-pituitary-thyroid axis. The assay was validated with the species Xenopus laevis, which is ...
Download or read book Carryover Effects of Hydroperiod Length Neonicotinoid Pesticide Exposure and Predation Risk in a Pond breeding Amphibian written by Cassandra Marie Thompson and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Amphibian species are declining globally, and are now one of the most threatened taxon, with over one-third of global amphibian species being listed by IUCN as Threatened, Endangered, or Critically Endangered. Foremost, the effects of climate change are pervasive across both terrestrial and aquatic systems, and synergies with other threats are actively contributing to current declines and local or global extinctions. Whether a species will be able to buffer itself against novel climate conditions and interactions with other environmental stressors will largely depend on their ability to respond through physiological and behavioral plasticity. Assessing these responses and their demographic consequences is particularly challenging for species with complex life cycles, such as amphibians, for which environmental variation can have different effects on demographic parameters across life stages. Environmental variation during development can have profound, variable effects on an organism's phenotype, fitness, morphology, and physiological attributes. As such, carryover effects from one life stage to another occur when an individuals’ early life experiences affect their fitness, performance, and demographic parameters at a later life stage. Aquatic stressors, such as temperature regimes, predation risk, pool hydroperiod, and exposure to contaminants often have sublethal impacts on the developmental environment of larval amphibians, which can affect morphology, behavior, and physiology throughout development and into later life stage. My doctoral research uses a range of meso- and microcosm experiments with larval and juvenile wood frogs (Rana sylvatica) to investigate (1) whether the innate plasticity of pond-breeding amphibians allows them to demographically compensate for negative carryover effects of various environmental stressors experienced during the larval stage and (2) how particular stressors may interact and cause synergistic, additive, or antagonistic effects on larval development and carryover effects. First, I investigated the carryover impacts of pond drying (hydroperiod length) on the development, survival, morphology, and locomotor performance of larval and juvenile frogs. Shorter hydroperiods resulted in lower larval survival and smaller sizes at metamorphosis. Post-metamorphic frogs from longer hydroperiod treatments grew faster and larger compared to individuals from shortest hydroperiods and had higher locomotor performance during endurance trials under various temperature and dehydrations regimes. Second, I quantified the developmental and behavioral effects of pond drying and sublethal neonicotinoid pesticide imidacloprid exposure on larval wood frogs.
Download or read book Ecotoxicology of Amphibians and Reptiles written by Donald W. Sparling and published by CRC Press. This book was released on 2010-06-02 with total page 946 pages. Available in PDF, EPUB and Kindle. Book excerpt: Building on the success of its popular predecessor, the second edition of Ecotoxicology of Amphibians and Reptiles presents newly available findings on the species that are important environmental indicators. This new edition covers nearly twice as many topics as the first, including recent developments in the ecotoxicology of amphibians and reptil
Download or read book Ecological Risk Assessment for Chlorpyrifos in Terrestrial and Aquatic Systems in the United States written by John P. Giesy and published by Springer Science & Business Media. This book was released on 2014-04-10 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reviews of Environmental Contamination and Toxicology attempts to provide concise, critical reviews of timely advances, philosophy and significant areas of accomplished or needed endeavor in the total field of xenobiotics, in any segment of the environment, as well as toxicological implications.
Download or read book An Introduction to Aquatic Toxicology written by Mikko Nikinmaa and published by Elsevier. This book was released on 2014-07-01 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: An Introduction to Aquatic Toxicology is an introductory reference for all aspects of toxicology pertaining to aquatic environments. As water sources diminish, the need to understand the effects that contaminants may have on aquatic organisms and ecosystems increases in importance. This book will provide you with a solid understanding of aquatic toxicology, its past, its cutting-edge present and its likely future. An Introduction to Aquatic Toxicology will introduce you to the global issue of aquatic contamination, detailing the major sources of contamination, from where they originate, and their effects on aquatic organisms and their environment. State-of-the-art toxicological topics covered include nanotoxicology, toxicogenomics, bioinformatics, transcriptomics, metabolomics, as well as water management and the toxicological effects of major environmental issues such as algal blooms, climate change and ocean acidification. This book is intended for anyone who wants to know more about the impact of toxicants on aquatic organisms and ecosystems, or to keep up to date with recent and future developments in the field. Provides with the latest perspectives on the impacts of toxicants on aquatic environments, such as nanotoxicology, toxicogenomics, ocean acidification and eutrophication Offers a complete overview, beginning with the origins of aquatic toxicology and concluding with potential future challenges Includes guidance on testing methods and a glossary of aquatic toxicology terms
Download or read book Recognition and Management of Pesticide Poisonings 5th Ed written by J. Routt Reigart and published by DIANE Publishing. This book was released on 2009-06 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 5th ed. is an update and expansion of the 1989 4th ed. This EPA manual provides health professionals with information on the health hazards of pesticides currently in use, and current consensus recommendations for management of poisonings and injuries caused by them. As with previous updates, this new ed. incorporates new pesticide products that are not necessarily widely known among health professionals. Contents: (1) General Information: Introduction; General Principles in the Management of Acute Pesticide Poisonings; Environmental and Occupational History; (2) Insecticides; (3) Herbicides; (4) Other Pesticides; (5) Index of Signs and Symptoms; Index of Pesticide Products. Charts and tables.
Download or read book Amphibian conservation action plan proceedings IUCN SSC Amphibian Conservation Summit 2005 written by and published by IUCN. This book was released on 2007 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Solitary Bees written by Bryan N. Danforth and published by Princeton University Press. This book was released on 2019-08-27 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most up-to-date and authoritative resource on the biology and evolution of solitary bees While social bees such as honey bees and bumble bees are familiar to most people, they comprise less than 10 percent of all bee species in the world. The vast majority of bees lead solitary lives, surviving without the help of a hive and using their own resources to fend off danger and protect their offspring. This book draws on new research to provide a comprehensive and authoritative overview of solitary bee biology, offering an unparalleled look at these remarkable insects. The Solitary Bees uses a modern phylogenetic framework to shed new light on the life histories and evolution of solitary bees. It explains the foraging behavior of solitary bees, their development, and competitive mating tactics. The book describes how they construct complex nests using an amazing variety of substrates and materials, and how solitary bees have co-opted beneficial mites, nematodes, and fungi to provide safe environments for their brood. It looks at how they have evolved intimate partnerships with flowering plants and examines their associations with predators, parasites, microbes, and other bees. This up-to-date synthesis of solitary bee biology is an essential resource for students and researchers, one that paves the way for future scholarship on the subject. Beautifully illustrated throughout, The Solitary Bees also documents the critical role solitary bees play as crop pollinators, and raises awareness of the dire threats they face, from habitat loss and climate change to pesticides, pathogens, parasites, and invasive species.
Download or read book Ecological Effects of Pesticides on Non target Species written by David Pimentel and published by . This book was released on 1971 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pesticides Industry Sales and Usage written by Arnold Lyle Aspelin and published by . This book was released on 1997 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AMPHIBIAN CONSERVATION written by Semlitsch R and published by Smithsonian. This book was released on 2003-06-17 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Leading amphibian biologist Semlitsch has assembled experts to tackle the timely issue of disappearing and deformed populations of amphibians. Every environmentalist will find this book an accessible and informative examination of what many scientists have called one of the major threats to the world's biodiversity.
Download or read book Short term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms written by and published by . This book was released on 1994 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
