A time-series analysis of airborne photographs and Landsat thematic mapper (TM and ETM+) images and hydrochemical data were used to examine the effects of land-use change from 1930 to 2001 on solute inputs to Lake Calado, a floodplain lake in the central Amazon. Deforestation from slash-and-burn agricultural activities has dramatically decreased the amount of primary growth upland and flooded forests in the basin.

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Coral cays form part of the Australian Great Barrier Reef. Coral cays with high densities of seabirds are areas of extreme nitrogen (N) enrichment with deposition rates of up to 1000 kg N ha(-1) y(-1). The ways in which N sources are utilised by coral cay plants, N is distributed within the cay, and whether or not seabird-derived N moves from cay to surrounding marine environments were investigated.

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An assessment of nitrogen sources to the Choptank and Patuxent River (including Island Creek), was conducted during the summer of 2003. Results demonstrated that both rivers were compromised with sewage derived nutrients. An Ecosystem Health Index for defined reporting regions was calculated from a variety of ecosystem heath parameters and then converted to a report card grade from A+ to D- and F for fail (Table 1).

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This newsletter details the importance of developing a scientifically rigorous, spatially explicit ecosystem health report card on Chesapeake Bay and its watershed to facilitate coordination and feedback between monitoring, management and research. A pilot study was conducted in July 2003 on the Patuxent and Choptank Rivers using a novel stable isotope technique (see "Assessing Nutrient Sources" newsletter below) together with more traditional water quality monitoring techniques.

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This newsletter describes the historical distributions of both native and introduced Phragmites. It details the invasion of the introduced type in North America (determined through genetic analysis), and morphological differences between the native and introduced types, as well as some commonly used control methods and their associated problems. Phragmites is thought to be one of the most widespread plants on earth.

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This newsletter discusses the effects of sea level rise, land subsidence and ground water extraction on the flooding and damage caused by Hurricane Isabel.

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This newsletter details the use of symbols as a visual language. Symbols are useful for depicting unequivocal messages that transcend cultures, languages and times. The use of symbols to contruct conceptual diagrams ('thought drawings') can be an effective tool for science communication and problem solving. Conceptual diagrams help to clarify thinking and provide a communication interface between scientists and non-scientists.

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This poster summarizes the key features of the seagrass communites in the Bocas del Toro archipelago, Panama. Seagrass meadows within this region are strongly influenced by their proximity to coral reefs, mangrove forests and coastal rivers. Reef, mangrove and river inputs influence sediment type and water clarity, two very important factors affecting the occurrence and abundance of seagrass meadows.

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This IAN newsletter explores the assessment of nutrient sources using stable isotope signatures of various marine organisms. This technique was developed in Moreton Bay, Australia for mapping sewage plumes, and was also used to determine the extent of aquaculture effluent (shrimp ponds) and to distinguish agricultural runoff (sugar cane) from other sources. The stable isotope ratio of nitrogen in organisms can be used to determine the influence of different nitrogen sources.

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