Download or read book Mercury Bioaccumulation Through Food Webs in Acidic Lakes at Kejimkujik National Park and National Historic Site Nova Scotia written by Brianna Wyn and published by . This book was released on 2007 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mercury Concentrations in Yellow Perch Perca Flavescens from 24 Lakes at Kejimkujik National Park Nova Scotia written by Jennifer A. Carter and published by [Halifax, N.S.] : Parks Canada. This book was released on 2001 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: As part of a wider study on the bioaccumulation & ecological effects of mercury in freshwater fish & wildlife in Canada, this study measured total mercury in yellow perch from 24 lakes in Nova Scotia. The objectives of the study were to assess mercury concentrations in prey of common loons, which themselves have high mercury levels, and to determine which environmental factors were associated with differences in fish mercury concentrations from lake to lake. Results presented include mean perch mercury concentration & concentration range, correlations of fish characteristics with whole-fish mercury concentrations, and correlations of water chemistry parameters with fish mercury concentrations.
Download or read book Environmental Chemistry and Toxicology of Mercury written by Guangliang Liu and published by John Wiley & Sons. This book was released on 2011-11-07 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides the fundamentals, recent developments, and future research needs for critical mercury transformation and transport processes, as well as the experimental methods that have been employed in recent studies. The coverage discusses the environmental behavior and toxicological effects of mercury on organisms, including humans, and provides case studies at the end of each chapter. Bringing together information normally spread across several books, this text is unique in covering the entire mercury cycle and providing a baseline for what is known and what uncertainties remain in respect to mercury cycling.
Download or read book Mercury Concentrations in Brook Trout and White Perch from Kejimkujik National Park Nova Scotia written by André D'Entremont and published by Halifax, N.S. : Parks Canada, Atlantic Region. This book was released on 1998 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study examines fillet mercury levels in brook trout (Salvelinus fontinalis) and white perch (Morone americana) collected from water bodies in Kejimkujik National Park. Mercury levels found in these species, important components of the local recreational fishery, are compared to those observed in other North American studies and to Health Canada guidelines regarding safe consumption of fish. Correlations are identified between total mercury concentrations and fish age, length, and weight. Differences in mean mercury concentrations among sampling locations are also noted, and possible sources of the mercury contamination are discussed.
Download or read book Homeostasis and Toxicology of Non essential Metals written by Chris M. Wood and published by Academic Press. This book was released on 2012 with total page 531 pages. Available in PDF, EPUB and Kindle. Book excerpt: Homeostasis and Toxicology of Non-Essential Metals synthesizes the explosion of new information on the molecular, cellular, and organismal handling of metals in fish in the past 15 years. These elements are no longer viewed by fish physiologists as "heavy metals" that kill fish by suffocation, but rather as interesting moieties that enter and leave fish by specific pathways, which are subject to physiological regulation. The metals featured in this volume are those about which there has been most public and scientific concern, and therefore are those most widely studied by fish researchers. Metals such as Ag, Al, Cd, Pb, Hg, As, Sr, and U have no known nutritive function in fish at present, but are toxic at fairly low levels.
Download or read book Water and Sediment Chemistry Influences on Mercury Bioaccumulation in Freshwater Invertebrates from Two Lakes in Kejimkujik National Park Nova Scotia written by Rachel G. Clarke and published by . This book was released on 2019 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cycling of Mercury in Kejimkujik National Park written by Canada. Environment Canada. Atlantic Region and published by [Sackville, N.B.] : Environment Canada, Atlantic Region. This book was released on 2001 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report is a mid-year summary of research on mercury cycling in the environment of Kejimkujik National Park in western Nova Scotia. It begins with a general introduction to mercury cycling and the sources of mercury in the park, followed by individual project reports organized by ecosystem component: lake sediments, atmosphere, water/air & air/soil fluxes, water, watersheds, geology, soils, and vegetation. The final project reports cover modelling, mass balance, analytical developments, and future mercury research. Includes a list of articles & reports produced from the research.
Download or read book Photoreactions of Mercury in the Freshwater Lakes of Kejimkujik National Park Nova Scotia written by Emma E. Vost and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury is a globally distributed, toxic environmental contaminant. Divalent mercury (Hg(II)) in freshwater lakes is reduced to volatile elemental mercury (Hg(0)) through reactions with Dissolved Organic Matter (DOM) and energy from solar radiation. Samples were collected from ten lakes in Kejimkujik National Park, Nova Scotia in May, 2008, 2009 and August 2010 and analysed for DOC (ranging 1.4 - 15.4 mg L-1), attenuation, anions, cations, and mercury photoreduction and oxidation rates. An integrated pseudo first order reaction equation was found to fit the gross reduction data extremely well (R2 value of >0.98; p value
Download or read book Methylmercury Photodemethylation in Kajimkujik Lakes written by Sara Jane Klapstein and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Methylmercury (MeHg) concentration in surface waters is a key variable regulating mercury availability to food webs. Few studies have quantified the seasonal importance of photodemethylation reactions and the influence of chromophoric dissolved organic matter (DOM) properties on these relationships. To address this research gap we have used numerous controlled experiments that focused primarily on the quantification of the relationships between solar radiation exposures, DOM, and MeHg within six freshwater lakes in Kejimkujik National Park and National Historic Site in Nova Scotia. The concentration of DOM was found to strongly control the photoreactivity of DOM in these study lakes across sampling seasons (R2=0.94). The effect of DOM photoreactivity on MeHg photodemethylation was directly tested using photochemically manipulated water from one lake collected in three different months. Photodemethylation rate constants and efficiencies tended to be higher in water collected during June, when in-situ DOM concentration was lower, than in water collected in August and October. Experiments that included water from all six lakes in summer and fall showed that DOM concentration could explain 76% of variation in photodemethylation rate constants. The outcomes from this combination of studies and experiments provide insight for prediction of photodemethylation potential in our study system and for comparison with MeHg concentrations in corresponding food webs. Methylmercury is associated with DOM (DOM-MeHg) in complexes, however in high DOM waters the proportion of DOM that is associated with MeHg (DOM-MeHg) will decrease and this MeHg-free DOM may be critical in regulating photodemethylation reactions. Photodemethylation will still occur in high DOM waters but at a limited rate because a smaller proportion of the photoreactions will involve DOM-MeHg complexes. This is the first study to test and quantify a competitive interaction between MeHg photodemethylation and DOM phototransformations (both photomineralization and photobleaching) to support the conceptual idea that higher dissolved organic carbon systems will have slower rates of photodemethylation. Overall, this compiled body of work yielded a method for predicting seasonal and spatial changes to MeHg concentrations in surface waters depending on environmental and physicochemical factors.
Download or read book Effects of Methylmercury on the General Health of Wild Fish in Kejimkujik National Park Nova Scotia written by Stephanie Graves and published by . This book was released on 2016 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Kejimkujik National Park and National Historic Site (KNPNHS), Nova Scotia is considered a biological mercury (Hg) hotspot because the yellow perch (Perca flavescens) and common loons (Gavia immer) inhabiting the lakes frequently exceed 'safe' levels of Hg. In this study, the relationship between Hg and overall health of three forage fish species (brown bullhead Ameirus nebulosus, banded killifish Fundulus diaphanus and golden shiner Notemigonus crysoleucas) in the lakes of KNPNHS was assessed using the endpoints condition factor, liversomatic index (LSI) and macrophage aggregates (MAs; indicators of tissue damage). Condition was negatively related to Hg in golden shiner and banded killifish, LSI was not related to Hg in any of the three species, and all species showed evidence of increasing MA prevalence with increasing Hg concentrations. These findings suggest that the health of wild fish species in KNPNHS is being affected by Hg, and that Hg concentrations similar to or greater than those found in the fish from KNPNHS are of concern for the health of other populations of wild fishes."--Leaf ii.
Download or read book Mercury Bioaccumulation in Fishes from Subalpine Lakes in the Wallowa whitman National Forest Northeastern Oregon and Western Idaho written by U.S. Department of the Interior and published by CreateSpace. This book was released on 2014-03 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury (Hg) is a globally distributed pollutant that poses considerable risks to human and wildlife health. Over the past 150 years since the advent of the industrial revolution, approximately 80 percent of global emissions have come from anthropogenic sources, largely fossil fuel combustion. As a result, atmospheric deposition of Hg has increased by up to 4-fold above pre-industrial times. Because of their isolation, remote high-elevation lakes represent unique environments for evaluating the bioaccumulation of atmospherically deposited Hg through freshwater food webs, as well as for evaluating the relative importance of Hg loading versus landscape influences on Hg bioaccumulation.
Download or read book The Fate of Atmospherically Deposited Mercury in Mountain Lake Food Webs and Implications for Fisheries Management written by and published by . This book was released on 2019 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mountain lakes are an iconic feature of the landscape in the Mountain West. They hold significant ecological and cultural value, and are important sentinels of environmental change. Despite their pristine image, these remote waterbodies are subjected to numerous anthropogenic stressors. Mountain lakes are naturally fishless systems, but historical fish stocking has led to major changes in mountain lake food web structure, including declines of resident amphibians, large-bodied zooplankton, and emergent insect populations. Atmospherically deposited contaminants, such as mercury, can accumulate in mountain lake food webs, leading to relatively high levels in the fish relative to the water. Managing for these stressors is difficult, because although fish stocking causes ecological problems, and mercury bioaccumulation poses human health risks, the cultural value of angling remains important. The goal of this dissertation was to better understand the issues of fish stocking and mercury bioaccumulation in a socioecological context: from the importance of trophic dynamics for mercury bioaccumulation in mountain lake fish, to the implications of fish stocking and mercury bioaccumulation for mountain lake management. In Chapter 2, I identified the ecological, limnological, and landscape-level indicators of mercury bioaccumulation in mountain lake food webs in order to inform better ecosystem management. In Chapter 3, I conducted an experiment to test if fatty acid stable isotopes can partition benthic and terrestrial prey sources in fish in a simplified mountain lake food web, in hopes of providing a more informative tool for future food web studies. In Chapter 4, I used intercept surveys to determine the public perceptions of mountain lake fisheries management in two national parks, and assess the risk mercury may pose to mountain lake anglers by determining fish consumption habits. This dissertation provides a unique set of tools that advance our understanding of food web dynamics and mercury bioaccumulation in mountain lakes, as well as the social value of these ecosystems. My results suggest that the most effective way to protect the health of mountain lakes and their visitors will be for managing agencies to collaborate with scientists and angling groups when making fisheries management decisions, and to invest in outreach about both the ecological and toxicological implications of fish stocking and mercury bioaccumulation in mountain lakes. The use of such socioecological research approaches is becoming progressively more important, as the threats of climate change and unstable regulatory protections for mountain ecosystems increase.
Download or read book Mercury Biomagnification Through Acidic Lake Food Webs in Relation to Lake Characteristics and Elemental Composition of Aquatic Organisms written by Meredith Clayden and published by . This book was released on 2012 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Among lake Variability in Methylmercury and Amino Acids in Aquatic Invertebrates from Kejimkujik National Park written by Jennifer C. Thera and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methylmercury (MeHg) is a neurotoxicant that is known to biomagnify in food webs and can result in fish consumption advisories. In aquatic invertebrates, MeHg concentrations are known to be highly variable (up to 30-fold) within and among freshwater systems and are a key predictor of mercury in fish, as diet is the main route of exposure. As such, there is global interest in understanding why some systems and invertebrate species accumulate more MeHg than others. The factors driving MeHg variability in aquatic invertebrates are not fully understood, but appear to correlate in part with diet and the physical and chemical parameters of the system. Since MeHg is primarily bound to the amino acid cysteine in proteins, my hypotheses were that cysteine content will be species-specific and that it will explain the within and among taxa variability in MeHg. In 2013 and 2014, food web taxa (benthic invertebrates, zooplankton, and fish) were collected from six lakes within Kejimkujik National Park, Nova Scotia, Canada that are known to vary in physical and chemical characteristics and biotic MeHg. Accurate detection and quantification of amino acids (especially thiols) are needed before they can be applied to the understanding of MeHg variability. I developed and validated a UPLC method to analyze amino acids in aquatic invertebrates, biofilm, and fish muscle. Overall, performance characteristics were reproducible, accurate, and comparable to other methods and tissues. The amino acid compositions of aquatic invertebrates, an understudied group, were significantly different based largely on their percentages of cysteine, histidine, proline, and aspartic acid + asparagine. Cysteine content differed among invertebrate taxa, with the lowest concentrations in Limnephilidae caddisflies (4.67 ± 0.58 nmol mg−1 tissue) and the highest concentrations in zooplankton (7.82 ± 2.88 nmol mg−1 tissue), but not among lakes (pH range 5.5-6.2). Primary consumers feeding on a benthic carbon source (Limnephilidae and Heptageniidae) had less cysteine and less MeHg than the pelagic primary consumers (bulk zooplankton). MeHg was significantly and positively related to cysteine content in five of the seven taxa. Despite this, more of the within-taxa variability was explained by [delta]15N, although this does not hold true when isotope data were adjusted for among-system differences in basal [delta]15N. This research generated new knowledge on 1) the importance of phylogenetics, diet, and lake characteristics in determining the amino acid composition of aquatic invertebrates and 2) on cysteine as a predictor of MeHg concentrations within aquatic invertebrates.
Download or read book Mercury Bioaccumulation in Dragonflies Odonata Anisoptera from Two Lakes in Kejimkujik National Park Nova Scotia written by Amy H. Buckland-Nicks and published by . This book was released on 2011 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Fish Community Complexity on Mercury Bioaccumulation in Lake Food Webs Supporting Brook Trout Salvelinus Fontinalis written by Monica Lynn Darlene Finley and published by . This book was released on 2013 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mercury Flux Measurements Over Air and Water in Kejimkujik National Park Nova Scotia written by Faisal S. Boudala and published by . This book was released on 2010 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
