“Large Marine Ecosystems are regions of ocean space encompassing coastal areas from river basins and estuaries to the seaward boundaries of continental shelves, enclosed and semi-enclosed seas, and the outer margins of the major current systems. They are relatively large regions, of the order of 200 000km² or greater, characterised by distinct bathymetry, hydrography, productivity, and trophically dependent populations. Within these 64 LMEs, 95% of the global marine capture fisheries are found, as well as most of the ocean pollution and coastal habitat alteration.”

Duda, D.A. and Sherman, K. A new imperative for improving management of large marine ecosystems. Ocean & Coastal Management 45 (2002). P. 797 - 833.

In June 1992, a follow-on action to the United Nations Conference on Environment and Development (UNCED) declaration was adopted by the majority of coastal nations. These were:

• prevent, reduce and control degradation of the marine environment so as to maintain and improve its life -support and productive capacities;

• develop and increase the potential of marine living resources to meet human nutritional needs as well as social, economic and development goals; and

• promote the integrated management and sustainable development of coastal areas and the marine environment.

In the immediate years following UNCED, increasing international concern was expressed over the deteriorating condition of the world’s coastal ecosystems that produce most of the world’s living marine resources.

Within the nearshore areas and extending seaward around the margins of land masses, it was noted that coastal ecosystems are being subjected to increasing stress from toxic effluents, over fishing, habitat degradation, excessive nutrient loading, harmful algal blooms, emergent diseases, fallout from aerosol contaminants and episodic losses of living marine resources from pollution effects and overexploitation.

To achieve the UNCED objectives, an ecological framework of management, the Large Marine Ecosystem (LME) concept was proposed and adopted. An essential component of such a management regime is the inclusion of a scientifically based strategy to monitor and assess the changing states and health of the ecosystems by tracking key biological and environmental parameters.

This management system includes regulatory, institutional and decision-making aspects as well as the scientific information on conditions, contaminants and resources at risk within the geographic extent of the ecosystem.

LMEs are described as relatively large bodies of water (200,000 sq. km) with distinctive bathymetry, hydrography, productivity and trophically dependent populations. Sixty four LMEs have been classified around the margins of the Atlantic, Pacific and Indian Oceans which produce 95 percent of the annual global fisheries biomass yields. An assessment of the state of LMEs is usually based on the following criteria: ecosystem productivity, fish and fisheries, pollution, socio-economic conditions and governance protocols.

The Global Environmental Facility (GEF) of the World Bank strongly endorses the strategy of country-driven LME management through its International Waters Programme. It promotes the incorporation of an interdisciplinary approach, along with a development component to improve the management of marine resources.

GEF places priority on the development of a Strategic Action Programme that addresses changing sectoral policies and activities responsible for the root causes of transboundary environmental concerns.

One of the main focal areas for GEF funding is to mitigate factors which cause stress to the ecosystem and to promote priority actions for improving environmental quality and the sustainable development of resources within LMEs important to the economic growth and food security of developing countries.

Open ocean and coastal LME projects that have received substantial GEF support in development and implementation are the Benguela Current, Guinea Current, Yellow Sea, Agulhas-Somali Current, South China Sea, Canary Current, Humboldt Current and the Bay of Bengal.