20 research outputs found

    Human transformations of the Wadden Sea ecosystem through time: a synthesis

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    Todayrsquos Wadden Sea is a heavily human-altered ecosystem. Shaped by natural forces since its origin 7,500 years ago, humans gradually gained dominance in influencing ecosystem structure and functioning. Here, we reconstruct the timeline of human impacts and the history of ecological changes in the Wadden Sea. We then discuss the ecosystem and societal consequences of observed changes, and conclude with management implications. Human influences have intensified and multiplied over time. Large-scale habitat transformation over the last 1,000 years has eliminated diverse terrestrial, freshwater, brackish and marine habitats. Intensive exploitation of everything from oysters to whales has depleted most large predators and habitat-building species since medieval times. In the twentieth century, pollution, eutrophication, species invasions and, presumably, climate change have had marked impacts on the Wadden Sea flora and fauna. Yet habitat loss and overexploitation were the two main causes for the extinction or severe depletion of 144 species (~20% of total macrobiota). The loss of biodiversity, large predators, special habitats, filter and storage capacity, and degradation in water quality have led to a simplification and homogenisation of the food web structure and ecosystem functioning that has affected the Wadden Sea ecosystem and coastal societies alike. Recent conservation efforts have reversed some negative trends by enabling some birds and mammals to recover and by creating new economic options for society. The Wadden Sea history provides a unique long-term perspective on ecological change, new objectives for conservation, restoration and management, and an ecological baseline that allows us to envision a rich, productive and diverse Wadden Sea ecosystem and coastal society

    Lost populations and preserving genetic diversity in the lion Panthera leo: Implications for its ex situ conservation

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    The original publication is available at www.springerlink.comTwo of the eight recognized lion subspecies, North African Barbary lion (Panthera leo leo) and South African Cape lion (Panthera leo melanochaita), have become extinct in the wild in the last 150 years. Based on sequences of mitochondrial DNA (mtDNA) control region (HVR1) extracted from museum specimens of four Barbary and one Cape lion, the former was probably a distinct population characterized by an invariable, unique mtDNA haplotype, whilst the latter was likely a part of the extant southern African lion population. Extinction of the Barbary line, which may still be found in "generic" zoo lions, would further erode lion genetic diversity. Therefore, appropriate management of such animals is important for maintaining the overall genetic diversity of the species. The mtDNA haplotype unique to the Barbary lion, in combination with the small size of the HVR1 analyzed (c. 130 bp), makes it possible and cost-effective to identify unlabelled Barbary specimens kept in museums and "generic" captive lions that may carry the Barbary line. An initial study of five samples from the lion collection of the King of Morocco, tested using this method, shows that they are not maternally Barbary. © Springer 2006.Ross Barnett, Nobuyuki Yamaguchi, Ian Barnes and Alan Coope
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