Sustainability, biomass yields, and health of coastal ecosystems: an ecological perspective

The sustainability, health and biomass ylelds of marine resources can be enhanced by the implementation of a more holistic and ecologically based strategy for assessing, monitoring, and managing coastal ecosystems than has been generally practiced during most of this century. A major milestone was reached in advancing toward a more ecologically based management practice when the majority of coastal nations of the world endorsed the declaration made at the United Nations Conference on Environment and Development (UNCED) in 1992, to 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. The scientific framework in support of the UNCED objectives is now emerging from a series of regional efforts aimed at cross-sectoral integration of research, monitoring, and assessments conducted to mitigate stresses on coastal ecosystems from toxic effluents, habitat degradation, nutrient loadings, harmful algal blooms, aerosol contaminants, and losses of living resources from pollution and overexploitation. Discipline-oriented ecological studies can contribute more toward achievement of resource sustainability when they are conducted withm a framework of science at the level of organization that is multidisciplinary and focused on populations, habitats, and ecosystems at large spatial scales. Primary, secondary, and tertiary driving forces of variability in biomass yields are examined for several large marine ecosystems, along with observations on changing states of 'health' of the systems. Marine resource problems underscored by UNCED are being addressed. Post-UNCED large marine ecosystem-scale programs for advancement toward resource sustainability, ecosystem health, and economically viable biomass yields are now being implemented. The programs are being supported by international agencies as part of an effort to couple recent advances in ecological monitoring, management, and stress mitigation strategies from the more developed countries, with the lesser developed coastal countries around the margins of the ocean basins.