valuable wetlands. Chabreck (1972) 

 estimated that this area contained 

 approximately 2.5 million acres 

 (1 million ha) of fresh to saline 

 marsh, 1.8 million acres (0.7 mil- 

 lion ha) of ponds and lakes, and 

 over 125,000 acres (50,588 ha) of 

 bayous and rivers in 1968. The LCR 

 has been divided into two main 

 physiographic units (Morgan 1973) : 

 the Deltaic Plain of the central 

 and eastern portions and the Chenier 

 Plain of the western portion 

 (Figure 1). Both of these regions 

 have been developed over the past 

 5,000 years by a series of prograd- 

 ing and overlapping deltaic lobes 

 composed of sediments transported 

 by the Lower Mississippi River and 

 its distributaries (Morgan 1973). 

 Both the Deltaic Plain and the 

 Chenier Plain have been the subject 

 of extensive ecological characteri- 

 zation efforts by the U.S. Fish and 

 Wildlife Service's National Coastal 

 Ecosystems Team. Based on Chabreck 

 (1972) and Gosselink et al. (1979), 

 it is estimated that 74 percent of 

 Louisiana's coastal marches occur 

 in the Deltaic Plain, while 26 per- 

 cent are found in the Chenier Plain. 



IMPORTANCE TO FISH AND WILDLIFE 



FISHERIES 



Louisiana leads the United 

 States in volume of commercial fish- 

 ery landings. Nearly 1.7 billion 

 pounds (0.8 billion kg) of commer- 

 cial fish and shellfish were landed 

 in Louisiana during 1978 (National 

 Marine Fisheries Service 1979). 

 The bulk of this catch is composed 

 of estuarine-dependent species in- 

 cluding menhaden, Atlantic croaker, 

 seatrout, spot, red drum, blue crab, 

 brown shrimp, white shrimp, and 

 American oyster. The LCR also sup- 



ports a large recreational fishery. 

 Approximately 580,000 persons ex- 

 pended over 5 million saltwater 

 angling days in the area in 1975, 

 spending over $35 million (U.S. Fish 

 and Wildlife Service 1977). It has 

 also been estimated that 6.9 million 

 days of sport crabbing effort occur- 

 red in the LCR in 1975 (U.S. Fish 

 and Wildlife Service 1977). Ap- 

 proximately 373,000 recreation days 

 were spent sport shrimping in the 

 LCR in 1968 (U.S. Fish and Wildlife 

 Service 1976). 



WILDLIFE 



The Louisiana coastal marshes 

 are of great importance to migratory 

 waterfowl, wintering more than two- 

 thirds of the entire Mississippi 

 Flyway waterfowl population in 

 recent years (Bellrose 1976) . Palm- 

 isano (1973) noted that one-fourth 

 of the North American puddle duck 

 population winters in these wet- 

 lands, with peak numbers of over 5.5 

 million of these birds recorded 

 during December 1970. Coastal 

 Louisiana's wetlands also support 

 over one-half of the continental 

 mottled duck population, with fall 

 populations of 75,000 to 120,000 

 birds reported (Bellrose 1976). 

 Diving ducks are also abundant in 

 the Louisiana coastal marshes and 

 adjacent waters during the fall and 

 winter months. More than 90 percent 

 of the Mississippi Flyway' s 870,000 

 lesser scaup winter in Louisiana, 

 primarily in its coastal zone. 

 (Bellrose 1976). In addition, near- 

 ly 38 percent of the canvasbacks 

 that winter in the Mississippi Fly- 

 way occur in Louisiana, mostly in 

 Six Mile and Wax Lakes of the Lower 

 Atchafalaya Basin and Atchafalaya 

 Delta (Bellrose 1976). Many ducks 

 present in fall and spring are 

 transients that utilize the LCR for 



388 



