Wildlife, along the Potomac as elsewhere, is dependent on whatever habitat it occupies--that is to say on the state of the landscape. If the rivers are cleaned up and kept flowing even during times of drought and heavy use of water, they will support better populations of fish and a greater variety of species. If the subtle interrelationships and the immense value of the estuary's varied nooks and crannies are recognized, studied out to full understanding, and protected--and in time--not only fish and shellfish but ducks and eagles and herons and all the other wild users of the shores and wetlands will benefit. Government refuges and other devices are badly needed for these purposes in that region, now that it is no longer remote and the kind of protection many private owners have traditionally furnished wildlife is diminishing. [Illustration] Upland populations of deer, turkey, grouse, quail, raccoon, fox, and other sporting and non-sporting species thrive in parts of the Basin suited to their habits and still in good condition, and shrink elsewhere. Many stretches of private forest land could support much higher densities of game and other wildlife, if they were put in better shape by practices that are available and feasible. Of the more than three million acres of such land scattered throughout the Basin in small holdings, much is in poor condition. It is therefore but spottily productive of game or timber or anything else, and often causes high runoff and erosion in critical watersheds. [Illustration] Recreation Many of the things we have called amenities here are subject to full-fledged economic uses necessary to the region's wellbeing and not usually in great conflict with scenic and ecological values if they are carried out right. Farming and commercial fishing and logging used to be generally exploitative and hard on the natural scheme of things in this country, for instance, but they no longer need to be and in most cases are not. Using the Potomac's water for towns and factories and power and navigation entails some interference with natural processes, but it does not have to be widely destructive of them. Discharge of treated wastes to streams is still necessary to a degree, and up to that degree not badly harmful, though as we have seen, it is far too often excessive. [Illustration] Urban expansion is necessary also with present population pressures. It is an irreversible exploitation of the landscape, but if the type of land-use principles mentioned in this chapter were to get wider employment, urbanization would quite certainly not have to be as destructive of natural and human values as its present usual form is. The same thing is true of industry in its many manifestations, including mining, and of the woven network of roads and utilities. The public needs them, and the people responsible for them need to be aware of the great value of the natural framework within which all men must exist.