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Hypoxia and Nutrient Reduction in the Coastal Zone

Hypoxia (or oxygen depletion) occurs when waters are overloaded with too many nutrients such as nitrogen, phosphorous and silicon, often arriving in coastal areas from farm fertilizers, municipal sewage systems and livestock waste. This report was inspired by the increasing number of hypoxic zones globally, which have doubled every 10 years over the past five decades, such that there are now over 500 such areas recorded. The authors of this report examined data about ocean areas where oxygen is drastically reducedalong with the social and environmental difficulties that arise with loss in marine life, fisheries, tourism, and decline in human health.  The study found that one of the most efficient ways to reduce oxygen depletion was to stem the flow of nutrients from fertilizers, municipal sewage or livestock waste into coastal waters. The report recommends that the GEF and its partners “urgently increase their support to nutrient reduction projects, building on GEF’s experience and leadership.” It also recommends, inter alia, that there be established principles to support tests of management responses to permanent and seasonal hypoxic zones, and that a toolkit for evaluating hypoxia and/or for addressing hypoxia and nutrient reduction should be developed for inclusion in the work of the GEF International Waters focal Area, including its Transboundary Diagnostic Analyses and Strategic Action Programs.

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