42 • Wetlands: Their Use and Regulation 



units) have substantial wetland components (90). 

 These 19 refuges represent approximately 50 per- 

 cent of the total visitation to all U.S. National 

 Wildlife Refuge units. Several of these refuges are 

 predominantly wetland environments: J. N. Ding 

 Darling Refuge in Florida, considered one of the 

 best birdwatching sites in the United States, had 

 671,000 visitors in 1981 (8th overall); Loxahatchee 

 Refuge in Florida had 333,329 visitors (19th); Oke- 

 fenokee Refuge, one of the oldest, largest, and wild- 

 est swamps in the United States, had 257,927 visit- 

 ors (21st); the Great Swamp Refuge, more than 

 half of which is wilderness within the New York 

 City Metropolitan Area, had 250,756 visitors (23d). 

 Recreational use of the Everglades National Park 

 in Florida averaged 675,000 from 1979 to 1981 (60). 



Wetlands also may provide learning opportuni- 

 ties for the general public or sites for educational 

 and scientific purposes. Research on such subjects 

 as botany, ornithology, and anthropology frequent- 

 ly is carried out in wetland areas. Environmental 

 education is a major theme in many parks and pub- 

 lic areas established around wetlands. For exam- 

 ple, the environmental center at Tinicum Marsh 

 on the outskirts of Philadelphia coordinates numer- 

 ous public education programs. In 1981 it had 

 32,730 visitors (60). 



From a purely scientific standpoint, the concept 

 of the ecosystem has played an important role in 

 environmental research and in the formal teaching 

 of ecology. Because of the importance of water to 

 the biosphere, most ecosystem study areas are se- 

 lected to include water bodies such as streams, 

 lakes, and wetlands. Wharton, (97) for instance, 

 describes the scientific opportunities available 

 through the Alcovy River Swamp: 



The Alcovy River is ideally suited for educational 

 uses: it is essentially unpolluted, it is located within 

 easy driving distance of a large metropolitan area 

 but is unaffected by it; and it contains a unique 

 swamp ecosystem found nowhere else in the Geor- 

 gia Piedmont. 



The river swamp has a diversity of habitats and 

 a corresponding diversity of plants and animals. 

 It offers aquatic communities of all types of water, 

 both flowing and still. The periodically high bio- 

 mass of certain plant and animal groups offers an 

 approach to community ecology and productivity. 



The drying up of bodies of water imitates both Pa- 

 leozoic and monsoonal climatic effects on life and 

 can illustrate the evolutionary transition from water 

 to land. The swamp shows rapid changes in physio- 

 chemical conditions. 



The yearly import of decomposed mineral mat- 

 ter can involve both geological and cultural (agri- 

 cultural) concepts. The processes of photosynthesis 

 and decomposition can be readily demonstrated. 

 Both the aquatic and the terrestrial segments of this 

 ecosystem are subject to an annual series of plant 

 and animal communities (succession), rapidly en- 

 forced by the regimen of the hydrocycle. Inverte- 

 brates such as clams, snails, leeches, adult aquatic 

 insects, and larvae of aerial forms are extremely 

 abundant — some of the species are "indicators" 

 of the degree of pollution present. 



Much of the swamp fauna (invertebrates, fish, 

 salamanders, mammals, birds) are present in mid- 

 winter, when other habitats are barren. Many of 

 the vertebrate groups are yearly renewable by in- 

 undation (fish), are fossorial (salmanders), or are 

 extremely plentiful (frogs). Thus, the animal com- 

 munity is not easily damaged or overcollected. 

 There are few subsurface runways to crush, or 

 delicate layers of litter and humus to compress, as 

 in a terrestrial forest. Most of the mammals are 

 renewable by migration from the river corridor if 

 accidentally killed; the tracks, droppings, or other 

 evidence of most are readily observable on the bare 

 swamp floor (raccoon, otter, mink, wildcat, beaver, 

 rodents, shrews). The ecosystem is adjusted to what 

 might be called "annual catastrophism." Even the 

 forest floor is changed and renewed to some extent 

 annually. 



Other Intrinsic Values 



In addition to those values previously discussed, 

 there may be other less obvious but just as impor- 

 tant reasons for preserving natural areas, including 

 wedands (28). Many plants and animals may have 

 great potential resource value for food, chemicals, 

 drugs, and so forth, but are as yet undiscovered 

 or undeveloped. Some scientists believe that all 

 species are an integral part of the natural environ- 

 ment and contribute in some, perhaps unknown, 

 way to its natural order and stability. The conserv- 

 ative belief is that excessive manmade impact on 

 this natural system could cause irreversible changes 

 in the natural order of the environment that may 



