Author: José Luis Roscales García
Publisher:
ISBN:
Category :
Languages : en
Pages : 204
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Exposure to contaminants, such as Persistent Organic Pollutants (POPs), is currently considered a serious anthropogenic threat to marine predators and their food webs. Exposure to contaminants by marine wildlife is mainly related to their trophic ecology, distribution and movements. However, the contribution of these biological features to pollutant levels remains poorly understood in most marine predators, including seabirds. New methodologies, including dietary and geographic tracers, such as stable isotope analyses, and a wide array of devices to track movement at different spatial and temporal scales, can provide new light into this issue. Although stable isotope signatures in marine wildlife provide valuable information about their trophic ecology, isotopic baseline levels also show geographical differences. Therefore, to understand isotopic differences among separate wildlife populations we first need to evaluate the influence of spatial variability in stable isotope signatures. In the present dissertation, some ecological factors, mainly feeding ecology, breeding locality and movements, and their influence shaping the isotopic signatures and the contaminant burdens, were examined in most Procellariiformes breeding in the Northeast Atlantic Ocean and the Mediterranean Sea. In particular, the isotopic signatures of Carbon and Nitrogen ([delta]13C and [delta]15N) as well as burdens of polycyclic aromatic hydrocarbons (PAHs) and organochlorinated compounds (OCs), e.g., polychlorinated biphenyls (PCBs) and pesticides such as 01T, in seabirds were determined. In this study, firstly, we evaluate the relative influence of geographic origin, movements and trophic ecology in shaping stable isotope signatures and contaminant burdens in pelagic seabirds. Then, we show the spatial patterns in the isotopic signatures, OCs and PAHs that emerge among Mediterranean and northeast Atlantic seabirds and evaluate pollutant sources and the influence of long-range transport mechanisms on these basins. Secondly, we provide evidences that show no marked differences in the trophic ecology of the studied seabird species throughout their breeding distributions, but clearly differ among species, pointing out the marked relationship of seabird trophic ecology with their PCB, 01T and PAH burdens. Overall, this study underlines the usefulness of combining environmental chemistry methodologies with new approaches in the study of animal ecology, showing the value of pelagic seabirds in marine contamination monitoring.
Author: Jose Luis Roscales García
Publisher:
ISBN:
Category :
Languages : en
Pages : 195
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Author: Melanie Bergmann
Publisher: Springer
ISBN: 3319165100
Category : Science
Languages : en
Pages : 456
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This book describes how man-made litter, primarily plastic, has spread into the remotest parts of the oceans and covers all aspects of this pollution problem from the impacts on wildlife and human health to socio-economic and political issues. Marine litter is a prime threat to marine wildlife, habitats and food webs worldwide. The book illustrates how advanced technologies from deep-sea research, microbiology and mathematic modelling as well as classic beach litter counts by volunteers contributed to the broad awareness of marine litter as a problem of global significance. The authors summarise more than five decades of marine litter research, which receives growing attention after the recent discovery of great oceanic garbage patches and the ubiquity of microscopic plastic particles in marine organisms and habitats. In 16 chapters, authors from all over the world have created a universal view on the diverse field of marine litter pollution, the biological impacts, dedicated research activities, and the various national and international legislative efforts to combat this environmental problem. They recommend future research directions necessary for a comprehensive understanding of this environmental issue and the development of efficient management strategies. This book addresses scientists, and it provides a solid knowledge base for policy makers, NGOs, and the broader public.
Author: Morgan E. Gilmour
Publisher:
ISBN: 9780438249554
Category :
Languages : en
Pages : 178
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Book Description
The vastness of the ocean makes it difficult to study. This is compounded by regional differences in temperature, wind patterns, underwater topography, and primary productivity that extend from the ocean's surface to depths of thousands of meters. Many organisms that inhabit the marine environment navigate many environmental changes as they move between regions in both the horizontal and vertical directions. The ability to navigate through different habitat types indicates that marine animals may be adaptable to multiple environments; however, it also suggests that they may be exposed to multiple hazards, including hazards of anthropogenic originches Rates of anthropogenic inputs of chemicals and litter to the atmosphere and the ocean are increasing. However, many effects of anthropogenic compounds on marine life are only beginning to be understood. In this dissertation, I assessed foraging ecology, contaminants, and the effects of contaminants, in seabirds, which are unique among marine animals because they hunt for fishes and squid from the air, but breed on land. Land-based breeding enables them to be easily studied, and they are good samplers of the vast ocean because they travel tens to thousands of kilometers from the breeding colony to forage. I first tested the hypothesis that seabirds' foraging behaviors are related to local oceanographic habitats, and that they exhibit behavioral plasticity to exploit the marine environment. GPS-tracking and remotely-sensed environmental data of four species of boobies ( Sula spp.) demonstrated adaptable behaviors that changed depending on the type of oceanographic habitat in which boobies foraged (e.g. based on depth, sea surface temperature and topography). Second, I measured blood-based persistent organic pollutants (POP) and mercury contaminant concentrations in boobies and two species of frigatebirds (Fregata spp.) from four colonies in the Pacific Ocean and Caribbean Sea. I combined blood-based contaminant measurements with two measures of foraging ecology (blood-based stable isotopes and GPS-tracking). Boobies and frigatebirds were exposed to different contaminants depending on their foraging habitat (e.g. nearshore vs offshore). Though three of the study sites were remote and uninhabited, all birds had contaminants. Lastly, I tested the hypothesis that mercury would negatively affect seabirds' breeding. I measured breeding in Flesh-footed Shearwaters (Ardenna carneipes) and Great-winged Petrels (Pterodroma macroptera ) in the Southern Ocean (Western Australia). Though Great-winged Petrels' blood mercury concentrations were the highest among all seabirds, I did not detect relationships between mercury and breeding in either species. Overall, seabirds are adaptive to their local marine environment. They traverse many habitat types while foraging, which influences the concentrations and types of contaminants that they encounter. However, they may be adapted, or tolerant, to some contaminants like mercury. Seabirds are good samplers of the marine environment, and continue to serve as good indicators of oceanographic processes and contaminants found in the ocean.
Author: Mark L. Tasker
Publisher:
ISBN:
Category : Environmental monitoring
Languages : en
Pages : 88
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Author: R.W. Furness
Publisher: Springer Science & Business Media
ISBN: 9401513228
Category : Science
Languages : en
Pages : 365
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Birds as Monitors of Environmental Change looks at how bird populations are affected by pollutants, water quality, and other physical changes and how this scientific knowledge can help in predicting the effects of pollutants and other physical changes in the environment.
Author: Robert W. Furness
Publisher: CRC Press
ISBN: 1351090054
Category : Science
Languages : en
Pages : 410
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The aim of this volume is to draw together state-of-the-art reviews of knowledge onlevels of heavy metals in marine environments (particularly in marine animals), the dynamicprocesses in these systems, toxic effects, and threats presented by heavy metals in foods ofmarine origin.All heavy metals, whether biologically essential or not, have the potential to be toxicto organisms at a threshold bioavailability. Such threshold concentrations vary betweenmetals, between species and with the physicochemical characteristics of the medium, somelike copper being particularly toxic even though essential in trace amounts. Responses ofanimals to metals in their medium or food depend to a large extent on the ability of speciesto regulate levels attained in their tissues. Higher animals have the capacity to regulate levelsof many metals, while marine invertebrates can regulate some within certain limits. Whereanimals cannot regulate physiological levels of metals, an alternative strategy is to detoxifyand store metals in relatively harmless forms. Knowledge of the manner in which animals deal with potentially toxic concentrations of heavy metals is of fundamental importance in the assessment of metal pollution by analysis of metal levels in biological samples. The interaction of heavy metals with biological materials is a key theme running through this volume. Toxic effects may be reflected at the individual, population, or ecosystem level, affecting species composition and production levels, or may be of direct dietary significance to man. The global cycling of metals through the marine environment is crucially affected by biological processes.
Author: R. W. Furness
Publisher: Springer Science & Business Media
ISBN: 1461320933
Category : Science
Languages : en
Pages : 210
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In the last few years there has been an excltmg upsurge in seabird research. There are several reasons for this. Man's increased ex ploitation of natural resources has led to a greater awareness of the potential conflicts with seabirds, and of the use of seabirds to indicate the damage we might be doing to our environment. Many seabird populations have increased dramatically in numbers and so seem more likely to conflict with man, for example through competition for food or transmission of diseases. Oil exploration and production has resulted in major studies of seabird distributions and ecology in relation to oil pollution. The possibility that seabirds may provide information on fish stock biology is now being critically investigated. Some seabird species have suffered serious declines in numbers and require conservation action to be taken to reduce the chances that they will become extinct. This requires an understanding of the factors determining their population size and dynamics.
Author: Alice Carravieri
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
Antarctic and subantarctic marine environments are reached by inorganic and organic contaminants through ocean circulation and atmospheric transport. Yet, environmental contamination is poorly known in the Southern Ocean, in particular in the Indian sector. Among environmental contaminants, mercury (Hg) and persistent organic pollutants (POPs) are primarily of concern, because they are toxic, highly mobile, and they bioaccumulate in the tissues of living organisms and biomagnify up the food web. Seabirds, as upper predators, are exposed to large quantities of contaminants via food intake and have widely served as biomonitors of marine contamination, notably through the non-destructive sampling of their feathers and blood. My doctoral work has focussed on the abundant and diverse seabird species (more than 40) breeding in the French Southern and Antarctic Lands, southern Indian Ocean, in order to describe and explain contaminant concentrations over a large latitudinal gradient, from Antarctica to the subtropics, and to identify the best bioindicator species for contaminant biomonitoring. In a first methodological step, seabirds with synchronous moult of body feathers (adult penguins and chicks of all species) were recognised as good candidates as bioindicators, because, unlike most adult birds, they present low within-individual variation in feather contaminant concentrations. In a second explanatory step, the influence of intrinsic (individual traits) and extrinsic factors (feeding ecology inferred from the stable isotope method) driving variation in contaminant concentrations was evaluated in feathers of the large avian community of the Kerguelen Islands (27 species) and in blood of wandering albatrosses from the Crozet Islands (180 birds of known individual traits). Feeding ecology was the main factor driving variation in contaminant concentrations of blood and feathers, both at the community, population and individual levels, whereas age, sex, phylogeny and breeding status played a minor role. Age-class was however an important intrinsic factor to consider, with chicks usually having lower concentrations than adults. In a third step, spatio-temporal patterns of contamination were studied through selected bioindicator species and by taking into account their feeding habits. Results from different species (oceanic seabirds) and populations (skua chicks) showed that, contrary to predictions, Hg exposure gradually increases from Antarctic to subantarctic and subtropical waters, whereas, in accordance with the global distillation theory, POPs exposure has the opposite pattern. Comparisons between penguin feathers from museum collections and contemporary samples showed that bird exposure to Hg is overall not different today when compared to 50-70 years ago, but subantarctic species are possibly experiencing an increasing trend. Future research efforts should be focussed on the use of feathers as biomonitoring tools, in particular for POPs determination. The best recommended bioindicator species include the emperor penguin and snow petrel (Antarctic), king penguin, blue petrel and black-browed albatross (subantarctic), and northern rockhopper penguin and Indian yellow-nosed albatross (subtropical). Future biomonitoring studies on these species will give invaluable insights into the poorly-known temporal trends of environmental contamination in the Southern Ocean.
Author: International Council for the Exploration of the Sea
Publisher:
ISBN:
Category : Fisheries
Languages : en
Pages : 604
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