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The Global International Waters Assessment

As common resources, international waters are among the most polluted and overexploited ecosystems on earth. And because they are not easily visible, environmental problems can build up unseen.

The Global International Waters Assessment (GIWA) is designed to fill information gaps. Set up in 1999 as a project of the Global Environment Facility (GEF) and led by UNEP, it is a global assessment of environmental state of all the world's transboundary waters based on existing and continuing studies from all sources.

The state of the waters is assessed by experts on each of the project's environmental and socioeconomic issues. The issues fall into five main focal areas: freshwater shortage, pollution, habitat and community modification, unsustainable exploitation of fish, and impacts of global environmental changes. The information was gathered by regional task teams and typically involved 10 to 15 environmental and socioeconomic experts from each country.

The matrix in the following pages presents a summary of the GIWA results for most of the 66 major water areas of the world (number-keyed on the map below). These geographic units are defined not by political borders but by hydrographic systems: the entire area of one or more catchment areas that drains into a single designated marine system. These marine systems often correspond to Large Marine Ecosystems. In some cases the regions have been further divided into subsystems.

The assessment integrates environmental and socioeconomic data from each country in a region to determine the severity of the impacts of each of the five concerns and their constituent issues on the entire region. The magnitude of the impacts was assessed using the best available information from a wide range of sources and the knowledge and experience of each of the team experts. So as to allow comparisons between different regions, the results were reported as standardized scores according to a four point scale: no known impact, slight impact, moderate impact and severe impact.

It can be seen that very few of the international waters are relatively free of impact so far - among the least affected are the Coral Sea east of New Guinea, and several ocean areas around Greenland, though even these are vulnerable to global change impacts. Among the worst affected across the most categories are the Gulf of Mexico (especially the Rio Grande and Mississippi sub-units) and the Caribbean sea; the Black, Aral and Caspian Seas; the Somali Current waters off the coast of East Africa; and the Sunda, Sulu-Celebes and South China Seas.

The GIWA methodology, progress and resources, with complete regional reports, and a table of the pre-defined criteria can be retrieved from the web site: http://www.giwa.net

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