Effectively resolving complex ecological policy problems may require something beyond traditional schemes such as command and control regulation of pollutants, maximum sustainable yield, or multiple use management. Normative science (i.e., science based on implicit policy preferences) has emerged as a basis of some of the most popular alternatives and modifications to traditional environmental or natural resources management. From the suite of contesting alternatives and modifications (e.g., ecosystem management, community-based environmental protection, bioregional management, ecological sustainability, ecological integrity, precautionary principle), the author uses 'ecosystem health' as an example of an approach based on normative science. As the understanding of ecosystem health matures beyond vague explanations, it is becoming increasingly contentious, partly because it embodies implicit policy preferences. At the core of the debate is a struggle over which societal values and preferences will take precedence. Whether current notions of ecosystem health will evolve sufficiently to overcome inherent weaknesses is uncertain. In sum, normative science, personified in concepts such as ecosystem health, with its tacitly derived value and preference character, provides limited help in reconciling the most divisive elements of ecological policy.

Modified from a talk given at the International Congress on Ecosystem Health, Sacramento, California, August 15-20, 1999. Environmental policy.