The Importance of Monitoring Change

This paper demonstrates how 25 years of more-or-less continuous monitoring of the Savannah River and of the Sabine River is able to show the effects of man's use of the river over time. The kinds of perturbation which are evident by such monitoring are the building of dams, the increase in organic pollution, and the effects of small amounts of toxic pollution. It demonstrates how this type of monitoring with stations located in various parts of the river can indicate the origin of pollution loads. Monitoring that is carried out continuously by the use of diatometers and intermittently by the study of major groups of organisms living in a river or estuary produces the best combination of facts concerning river conditions and water quality.