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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This newsletter is a summary of the history, mission and accomplishments of the University of Maryland Center for Environmental Science (UMCES). This summary has been prepared to provide a sense of where we have come from, what we are doing and where we are going. It also serves to identify the collaborative role UMCES plays within the University System and the State of Maryland.

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A module of dynamic parameterization is added into the HSPF watershed software for simulation of dissolved inorganic nitrogen (DIN) export from forest associated with gypsy moth defoliation. It simulates a changing ecosystem following the breakout of defoliation, such as increasing mineralization and nitrification rates and soil temperature, and decreasing interception of precipitation, plant nitrogen uptake rate and evapotranspiration.

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Coral bleaching events have become more frequent and widespread, largely due to elevated sea surface temperatures. Global climate change could lead to increased variability of sea surface temperatures, through influences on climate systems, e.g. El Nino Southern Oscillation (ENSO). Field observations in 1999, following a strong ENSO, revealed that corals bleached in winter after unusually cold weather.

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