Author: Alice Carravieri
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
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: J. P. Croxall
Publisher: Cambridge University Press
ISBN: 9780521301787
Category : Nature
Languages : en
Pages : 460
Get Book Here
Book Description
Originally published in 1986, this book is concerned with the ways in which seabirds function as predators in the marine environment; in particular about how they find and catch food and how much of it they consume. It reviews both the feeding ecology of seabirds (including adaptations for flight and diving) and also most of the leading field studies (in polar, temperate and tropical regions) that have quantitatively examined the interactions of seabird communities with their prey.
Author: Muhammad Nawaz Rajpar
Publisher:
ISBN:
Category : Science
Languages : en
Pages :
Get Book Here
Book Description
Seabirds are those waterbirds that directly or indirectly depend on the marine environment over the waters, id est, they foraged at sea either near shore or offshore and inhabit in coastal areas, islands, estuaries, wetlands, and ocean islands. They are mostly aerial waterbirds sailing above sea spending much of their time (weeks, months, and even years) in marine environments or floating on the water surface or diving in deep sea in search of food. Seabirds encompass of 65 genera, 222 marine, and 72 partially marine bird species. Seabirds have been used as good indicators (id est, bioindicators) of marine ecosystems due to cause-effect association with different microclimate and habitats. They exploit broad scale of habitat, quickly respond to environmental changes, they can be detected easily (id est, they showed their presence through vocalization), easy to identify, can be surveyed efficiently over large spatial scale, e.g., presence, abundance, and influenced by surrounding habitats as compared to other animals. Employing seabird as bioindicators is a cost-effective and informative tool (well defined matrix) to determine the effects of disturbances, contamination, id est, effects of pollutants, organic substances, and oil-spills of the marine environment. Seabirds are top predators in the marine food chain and key component of the food web. Seabirds may indicate the status of habitat, reduction in food occurrence and abundance, rate of the predation, an effect of weather (climate change), and threats. The other reason could be that, seabirds often closely associate with inter-site more distinctly than other animals and may breed in the same site each year, easy to catch while incubating and during rearing chicks. Hence, it is crucially important to use seabirds as bioindicators within the context of ecological and spatial parameters to determine the effects of disturbances in the marine environment and for effective conservation and better management of seabirds in the future.
Author: Jaime A. Ramos
Publisher: CRC Press
ISBN: 1000622576
Category : Nature
Languages : en
Pages : 271
Get Book Here
Book Description
Seabirds are global travellers connecting oceans and seas all over the world, and facing multiple threats at local and global scales. Seabirds are long-lived top predators, reflecting changes at lower trophic levels, and are good models to assess ecological changes produced by human societies. Thus, world-wide collaborations are needed to understand seabird ecology and to develop effective conservation measures benefitting both humans and seabird populations. This book provides a modern overview on seabird biodiversity studies: it begins by covering the most up-to-date techniques to study seabirds, and then focus on pragmatic issues related with interactions between seabirds and humans, the use of seabirds as ecological indicators and conservation of seabirds. It gives an updated insight on all these topics and highlights gaps that need further development for a comprehensive understanding of the relationships between seabirds and human actions. This book covers the response of the seabird research community to a biodiversity crisis aiming to contribute towards environmental sustainability. It should provide inspiration to a wide range of professionals and students, including the much needed world-wide collaboration between research groups and practitioners. In this way seabird research and conservation provide an inspiration for the solution of global issues such as climate change.
Author: Heimo Mikkola
Publisher: BoD – Books on Demand
ISBN: 1789236568
Category : Science
Languages : en
Pages : 112
Get Book Here
Book Description
Changes in seabird populations are good indicators of large-scale and long-term change in marine ecosystems, and are important because of their global impacts on the marine environment. This book has six chapters that present a wide variety of global seabird-related issues, from India to Svalbard, Norway. It also gives a comprehensive history of the use and chemical content of guano and certification schemes in fisheries for seabird conservation in Argentina. With the knowledge available in this book we should know how best to protect seabirds, which need all our support to survive in changing environments and climates. We can all do our best to recycle plastic waste to reduce global plastic pollution, which has affected seabirds' physical state, food sources, and nesting areas.
Author: Cinzia Verde
Publisher: Springer Science & Business Media
ISBN: 3642273491
Category : Science
Languages : en
Pages : 258
Get Book Here
Book Description
The second volume of “Adaptation and Evolution in Marine Environments – The Impacts of Global Change on Biodiversity” from the series “From Pole to Pole” integrates the marine biology contribution of the first tome to the IPY 2007-2009, presenting overviews of organisms (from bacteria and ciliates to higher vertebrates) thriving on polar continental shelves, slopes and deep sea. The speed and extent of warming in the Arctic and in regions of Antarctica (the Peninsula, at the present ) are greater than elsewhere. Changes impact several parameters, in particular the extent of sea ice; organisms, ecosystems and communities that became finely adapted to increasing cold in the course of millions of years are now becoming vulnerable, and biodiversity is threatened. Investigating evolutionary adaptations helps to foresee the impact of changes in temperate areas, highlighting the invaluable contribution of polar marine research to present and future outcomes of the IPY in the Earth system scenario.
Author: R. W. Furness
Publisher: Springer Science & Business Media
ISBN: 1461320933
Category : Science
Languages : en
Pages : 210
Get Book Here
Book Description
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: Joshua Cunningham
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Seabirds are considered strong bioindicators of marine health and changes in seabird ecology can reflect issues in the surrounding marine environment. In this thesis, seabird ecology was examined at several scales to see if seabirds could indicate changes in the marine ecosystem. In Chapter 1, rhinoceros auklet (Cerorhinca monocerata) chick diets were used to detect changes in prey availability among and within years. Changes in diet within years was likely due to prey life-history traits, while changes among years were reflective of changes in the surrounding marine environment. Chapter 2 compared the population trends of seabirds on Middleton Island to colonies in the Gulf of Alaska for evidence of population synchrony. Seabird populations declined across the Gulf of Alaska, potentially due to the 1977 warm water regime shift. However, populations of select seabirds on Middleton Island contrasted their species' large-scale population trends, suggesting that local factors played important roles in the population trends of these seabirds. These results demonstrate how seabirds can indicate large changes in their environment (population declines), but how using individual colonies, such as Middleton Island, may not detect these large changes in the marine environment due to local influence. Together these chapters demonstrate the value of seabirds as bioindicators and their ability of to detect changes in the marine environment at varying scales. The result of this thesis strengthens our knowledge of seabird biology and ecology, and their ability to be bioindicators of marine environments.
Author: Derek J. Onley
Publisher: Convention
ISBN:
Category : Nature
Languages : en
Pages : 92
Get Book Here
Book Description
In recent years there has been a sharp decline in the populations of several seabird species, particularly albatrosses. The decline has been widely attributed to fishing with longlines. Seabirds feed on longline baits, get hooked, and drown. This book has been written to help scientific observers identify those seabirds likely to be caught in the Southern Ocean, and takes into account the requirements of the CCAMLR Scheme of International Scientific Observation. It covers the identification of 36 species of birds from the Southern Ocean that have been caught in fishing gear or have been seen feeding from fishing boats. By carefully following the keys to identification, observers should be able to identify most seabirds caught in commercial fisheries in the Southern Ocean with confidence
Author: A.M. GRIFFITHS
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
