Wise management of our freshwater supplies is a privileged obligation. We owe, therefore, thoughtful consideration to the growing problems associated with our aquatic resources so that future generations will not accuse us of careless damage to their heritage. In order to utilize our lakes and streams efficiently, however, fundamental processes of aquatic environments and communities, their trends, rates, and interacting factors must be better understood. Results from studies in experimental limnology, in my opinion, will guide us toward intelligent use of lakes and streams. Moreover, these studies may give us knowledge for understanding the sea as well.