Ecosystem health as measured from the molecular to the community level of organization,with reference to sediment bioassessment

The current recognition that chemical measurements are uncertain indicators of biological consequences of pollution has shifted the emphasis away from assessing environmental chemistry alone toward the inclusion of measurements of the health of organisms. Effects of pollutants begin with the individual, have subsequent repercussions on population level processes, and ramifications for community structure and functions. Pollutants act at a molecular level and the biochemical lesions is the first step in the manifestation of effects. Technologies that operate at the cellular level assist in elucidating toxicity. Higher levels of integration include an organism's capacity for growth. Laboratory bioassays andin situ research can monitor physiological incapacities and assist in predicting population level effects. A yet higher level of organization is that of the ecological community.