quantities and rates that can affect the 

 local environment (Bahr and Lanier 1981; 

 Bahr, unpublished data). Major oyster 

 reefs are located in the MDPR from 

 Atchafalaya Bay westward to the end of 

 the Vermilion hydrologic unit (Figure 

 62). Although many of these reefs are 

 dead, they continue to affect sedimenta- 

 tion patterns, and they are an important 

 economic resource as calcium carbonate 

 that is used in the manufacture of 

 cement and aluminum, and for road- 

 building. Some dredged shells are used 

 as oyster cultch, although this cultch 

 is sometimes exported from Louisiana to 

 other oyster growing states. 



There is some controversy about the 

 regulation of dredging clam and oyster 

 shells from fossil beds in the Louisiana 

 portion of the MDPR (e.g., Baton Rouge 

 Morning Advocate, 1982a and b) . The 

 Louisiana State Government instituted in 

 1912 a policy whereby the Louisiana Con- 

 servation Commission (predecessor of the 

 Wildlife and Fisheries Commission, now 

 the Department of Wildlife and Fisher- 

 ies) receives a portion of its funding 

 in the form of royalties from the shell 

 dredging industry, based on the volume 

 of shells dredged (Gulf South Research 

 Institute 1977). This royalty is pre- 

 sently $0.25/yd 3 of shell. Because 

 Wildlife and Fisheries is partially re- 

 sponsible for overseeing the protection 

 of fisheries resources and coastal habi- 

 tats that may be affected by dredging of 

 clam shells and/or oyster reef shells, a 

 potential conflict of interest exists. 

 The Coastal Management Section of the 

 Louisiana Department of Natural Re- 

 sources and the USACE will this year 

 (1982) determine whether to grant State 

 and Federal shell dredging permits to 

 two applicants. The U.S. Fish and Wild- 

 life Service has submitted a statement 

 to these agencies recommending that reef 

 dredging permits be conditioned to ex- 

 clude the following areas: all exposed 

 oyster reefs, the area surrounding 

 Southwest Pass on the west end of Marsh 

 Island, 1 mile around Shell Keys Na- 

 tional Wildlife Refuge, and the 2-foot 

 depth contour of the Atchafalaya Delta 

 (U.S. Fish and Wildlife Service 1982). 



Several groups of birds feed in 

 mudflat areas; wading birds, shallow- 



probing birds, and deep-probing birds 

 (Peterson and Peterson 1979) . Most 

 wading birds are fish-eaters, although 

 some species also consume fiddler crabs 

 and other small crustaceans that are 

 found on mudflats. Most of these birds 

 fish in the shallow water adjacent to 

 the mudflat or in tidal pools on the 

 surface of the flat. Shallow-probing 

 birds include several species of sand- 

 pipers, plovers, oystercatchers, rails, 

 and dowitchers. Many of these species 

 depend on mudflat areas for most of 

 their food. These birds are opportun- 

 istic feeders, i.e., they eat those spe- 

 cies of infauna that are most abundant. 

 Some birds feed on the insects and 

 crustaceans found on the surface of the 

 mudflat. The deeper probing birds are 

 able to feed on larger invertebrates; 

 these birds include willets, long-billed 

 curlews, godwits, and whimbrels. Some 

 birds feed on ocean beaches as well as 

 mudflats, and the distinction between 

 beaches and mudflats breaks down in many 

 parts of the MDPR where the marine 

 energy regime is low. For example, mud- 

 flats are currently building in the gulf 

 to the west of Atchafalaya Bay, seaward 

 of the beach habitat. 



Until the mudflat habitat in the 

 MDPR has been investigated further, lit- 

 tle can be reported of a quantitative 

 nature about its overall role in nutri- 

 ent regulation and energy flow. The 

 evidence suggests that mudflats may be a 

 critical habitat for certain species of 

 birds and may play an important role in 

 nutrient processing in estuarine areas. 



NEARSHORE GULF (13) 



The nearshore gulf habitat in the 

 MDPR is defined in this report as being 

 limited to high salinity and relatively 

 high energy areas (Figure 30). Thus, 

 this habitat is found exclusively to the 

 east of the Chandeleurs and to the south 

 of the Mississippi Gulf Islands (in the 

 Mississippi Sound hydrologic unit). The 

 nearshore area to the west of the Mis- 

 sissippi River is defined as estuarine 

 open water, because of its relatively 

 low salinity resulting from the fresh- 

 water inputs from the Mississippi and 

 Atchafalaya Rivers. 



62 



