Because information from those programs is confined to a few narrow areas, toxics in much of the Bay have gone largely unexamined. As a result, there is little information about impacts from the mostly unregulated nonpoint sources, or effects cau sed by the cumulative impacts of several substances on aquatic life. Recognizing that information gap, the Bay Program's 1988 Basinwide Toxics Reduction Strategy called for a more comprehensive approach toward assessing the impact of toxics on living resources in the environment. That led to a 1989 workshop in which scientists from across the nation came together to decide what a more comprehensive monitoring program should look like. Participants concluded that such a program should use a variety of sensitive species as indicators, and that it should look at the impacts in both the water and in the sediments.
Different organisms are sensitive to different things.
In the tests, scientists also attempted to sort out factors such as salinity, dissolved oxygen, pH, and other factors which could affect survival. Scientists look not only for survival, but changes in reproduction, growth, behavior, and other impacts. Any differences between the species in the tests, and those exposed to uncontaminated conditions, is noted. The program looks separately for impacts in the sediments and the water because different kinds of organisms can be exposed to toxics in each environment. In addition, because toxics gradually sink to the bottom, sediments provide an idea of the amount of toxics which are accumulating in a particular area.