This intentionally designed and managed ecosystem represents a symbiosis of urban and natural processes. Food production, wildlife habitats, recreation dwelling, resource con servation, water and nutrient recycling, and visual amenity are joined in a network of inter dependence. composition as a whole is very different from the estuarine ecosystem that The would still exist at San Elijo had man never arrived on the scene, being more varied in its forms and more intense in its activities. Although it is dependent on human energy and ingenuity for its stability, the reverse is also, to some degree, true. If all goes well, if our mod els are correct and our design works as it should, and if the management is both imagi. native and sound, then human and natural processes will merge indistinguishably into an organic whole, a human ecosystem in the best sense of the term. That,hard as it may be to achieve, is the ideal.