The total number of consumer species reported 

 to use different wetland habitats (table 4.5) generally 

 increases as one moves inland from salt marshes to 

 fresh marshes and is greatest in the swamp forest 

 habitat. This trend probably reflects the decreasing 

 salt stress, especially for mammals, ampliibians, and 

 reptiles, and the high niche diversity of the swamp. 



4.2.8 NATURAL WETLAND VALUES 



Wetlands are valuable to man in a number of 



ways: 



1. Wetlands serve as habitats for birds, fur- 

 bearers, and other wildhfe important for 

 both commerce and recreation. (Species of 

 particular interest, e.g., muskrat, nutria, 

 white-tailed deer, river otter, wading birds, 

 and waterfowl are discussed in part 5). 



2. Wetlands serve as nurseries for most fish and 

 shellfish species of commercial and recrea- 

 tional interest. (Shrimp, menhaden, and 

 sportfish are discussed in part 5). 



3. Swamp forests are a source of timber particu- 

 larly cypress which is valuable because of its 

 resistance to decay. 



4. Wetlands purify flooding water and buffer 

 adjacent estuaries against large changes in 

 upstream inputs of nutrients and wastes. 

 Wetland sediments can reduce metals and or- 

 ganic toxins in flooding waters (Anonymous 

 1977). They perform valuable tertiary treat- 

 ment in urban areas where sewage wastes are 

 discharged into estuaries (Gosselink et al. 

 1974). 



5. Natural wetlands have aesthetic value in 

 addition to commercial and wildlife value. 



6. On a global scale wetlands may be important 

 in maintaining and controlling the normal 

 cycles of nitrogen and sulfur (Deevey 1970). 

 Both of these elements require the juxta- 

 position of oxidized and reduced sediment 

 zones, a condition found in shallow coastal 

 wetlands. 



7. Wetlands buffer inlands from the damaging 

 effects of hurricanes and otlier severe storms. 

 They are significant floodwater reservoirs 

 which reduce flooding in surrounding up- 

 lands. 



8. Natural wetlands reduce maintenance dredg- 

 ing costs of deep water passes by trapping 

 silt. (Impounded or drained wetlands cannot 

 trap silt.) Additionally, scouring of passes 

 decreases because water currents are reduced 

 as intertidal volume decreases (Coates 1972). 



Two factors that have made wetland management 

 and preservation particularly difficult in the Chenier 

 Plain are (1) the monetary return of the renewable 

 resources of wetlands to the private owner is often 

 very small compared to the value of the subsurface 

 minerals; (2) most of the value of the renewable re- 

 sources of wetlands accrues to society as a whole or 

 some significant portion of it, not to the private 

 owner. 



The owner of wetland acreage in the Chenier Plain 

 enjoys direct economic benefits only from trapping 

 and from leasing his land to hunters. The combined 

 actual return for these uses is under $25/ha/yr 

 ($10/a/yr) (Robert Chabreck, Pers. Comm., School of 

 Forestry and Wildlife Management, Louisiana State 

 University, Baton Rouge). In contrast, extracted oil 

 and gas may amount to thousands of dollars per acre. 

 Thus, it is often difficult to convince the owner that 

 sound ecological conservation practices are important. 



The social value of renewable wetland resources 

 is one to two orders of magnitude greater than the 

 direct value to the private owner. For instance, in con- 

 trast to the $25/ha/yr ($10/a/yr) the owner might 

 conceivably recover, the commercial and sportfishing 

 value which accrues to another segment of society is 

 around $250/ha/yr ($100/a/yr) and the tertiary 

 sewage treatment services to a nearby metropolitan 

 area may be valued at over $2,500/ha/yr ($1000/a/yr) 

 (GosseUnk et al. 1974). 



1,000 



FLORIDA f 



Inshore shrimp yields rnt 



Figure 4-19. The relation of Louisiana and Florida inland shrimp landings to the area of marsh adjoining the 

 estuary in which the shrimp were cauglit (Turner 1977a). 



171 



