AbstractContinued overfishing in the face of scientific warnings, fishing down food webs, destruction of habitat, and accelerated pollution loading-especially nitrogen export-have resulted in significant degradation to coastal and marine ecosystems of both rich and poor nations. Fragmentation among institutions, international agencies, and disciplines, lack of cooperation among nations sharing marine ecosystems, and weak national policies, legislation and enforcement all contribute to the need for a new imperative for adopting ecosystem-based approaches to managing human activities in these systems in order to avoid serious social and economic disruption. The global environment facility (GEF) has been approached by developing countries in overwhelming numbers for assistance in securing the futures of their shared large marine ecosystems (LMEs). This presentation describes the LME assessment approach to assist developing countries in Asia, Africa, Latin America and eastern Europe in the management of human activities affecting coastal and marine ecosystems and linked freshwater basins. At risk are renewable goods and services valued at an estimated $12.6 trillion/year. There are 110 countries involved in 16 LME projects approved by the GEF Council or under preparation. A five-module assessment and management methodology is being applied that moves the countries towards adopting practical joint governance institutions through place-based management. This LME approach engages stakeholders, fosters the participation of the science community and leads to the development of adaptive management practices that are assisting participating countries in making the transition towards recovery and sustainable development of marine resources.