Louisiana Coastal Wetland Functions and Values
Natural wetland functions that produce benefits to coastal populations include: buffering storm impacts; storing and conveying floodwater; absorbing nutrients, sediment and contaminants; maintaining high biological productivity and biodiversity; and serving as a nursery ground for fish and habitat for wildlife, as well as the base for ecosystem food webs (Smith 1993). In terms of natural services, biologic productivity and infrastructural investments, the value of Louisiana’s coastal wetlands exceeds $100 billion (Louisiana Coastal Wetlands Conservation and Restoration Task Force [LCWCRTF] 1993). Many coastal populations, especially those in Louisiana, rely on these functions for their very livelihood and continued existence. The projects presented in the Restoration Plan involve an estimated total investment of only $1 billion to $3 billion over the next 20 years to sustain this valuable system.
When the Acadian people migrated from Canada to Louisiana in the 1700s, bountiful natural resources prompted them to settle in the extensive wetlands of Louisiana (Kniffen 1968). Today, Louisiana’s coastal wetlands support a diverse population represented by cultures from around the world. The lifestyle for many coastal residents is centered around harvesting wetland resources and has been preserved through time primarily because Louisiana contains over three million acres of marshes, swamps, bottomland hardwoods, forest and barrier island habitats. Louisiana currently has the highest acreage of salt marsh of any state in the union (Field et al. 1991) (figure 2), a system more productive than many intensely used agricultural lands. However, Louisiana also accounts for 80% of the nation’s coastal land loss, with its valuable wetlands disappearing at a dramatically high rate, ranging between 25 (Dunbar et al 1992) and 35 (Barras et al 1994) square miles per year.
The loss of Louisiana’s coastal wetlands results in the loss of valuable functions they serve. This is reflected in changes in the living resource base, and the associated economic and aesthetic benefits, as well as through direct effects on local communities and cultures.
The fishing industry is very important to the state’s economy. With greater than 1.1 billion pounds of fish and shellfish harvested annually, domestic and commercial landing statistics indicate that Louisiana provides more fishery landings than any other state in the conterminous United States (USDOC 1996) (figure 3). In fact, as much as 16% of the nation’s fisheries harvest, including shrimp, crabs, crayfish, oysters and many finfish, comes from Louisiana’s coast (USDOC 1996). Over 75% of Louisiana’s commercially harvested fish and shellfish species are dependent on wetlands. Coastal wetlands provide valuable breeding, spawning, feeding and nursery grounds for many of these species at some point during their life cycles (figure 4).
The length of the land-water interface has been identified as one of the most important features of wetland habitat related to biological productivity (Browder et al. 1989). This is because land-water interface provides access to food resources for nekton and refuge from predators. Thus, as coastal wetlands continue to break up, there will be a short-term increase in land-water interface and an increase in fisheries production. This seems to be borne out by increases in landings of both brown and white shrimp since 1960 (Boesch et al. 1994). Similarly, once wetland deterioration proceeds to the point where the length of the land-water interface begins to decline, there will be a long-term decline in fishery productivity. These declines may have already begun or may occur soon in coastal Louisiana unless the situation is remedied (figure 5).
In addition to its valuable fisheries harvest, Louisiana is undoubtedly one of the most important states in the southeastern United States in terms of colony sites and total number of nesting waterbirds (Spendelow and Patton 1988). The state provides habitat for five million wintering waterfowl, and is utilized as a stopover point for waterfowl during migration to and from Central and South America (Helmers 1992). Louisiana’s coastal wetlands also provide habitat for several federally listed threatened and endangered species, including the brown pelican and at least 70 pair of nesting bald eagles (LCWCRTF 1993). Some species have experienced declines, reportedly due to loss of wetland habitat over the last two decades. Neo-tropical migrants will lose vital resting areas as acreage of barrier islands (Condrey et al. 1995), cheniers and natural levee forests (Olson and Noble 1976) decline.
The largest fur harvest in the United States comes from Louisiana. More than 40% of the nation’s wild fur harvests come from Louisiana wetlands, including nutria, muskrat, mink, raccoon, otter, bobcat, beaver, coyote and opossum. Over 25,000 wild alligators are harvested yearly from Louisiana’s wetlands, with hides and meat from both wild and farm harvests exceeding $16 million in 1992. Alligators are abundant in fresh and slightly brackish lakes and streams, and build nests in adjacent marshes. Farm-raised alligators are taken as eggs from the wild and then hatched in captivity, with some being returned to the wild. Both wild and farm-raised alligators are vitally linked to Louisiana’s wetlands and thus will decline with continued wetland deterioration (Coreil 1994).
Direct Effects on Population and Culture
Without the wetlands in south Louisiana, over two million people would have to relocate and the way of life that has been preserved for centuries would be diminished (LCWCRTF 1993). A direct benefit that coastal wetlands offer to inhabitants is the protection of coastal development infrastructure from hurricanes and other storm surges. Louisiana’s entire coastal zone is plagued with frequent hurricanes, tropical storms and tropical depressions (figure 6). In south Florida, where there are virtually no wetlands between the Atlantic Ocean and developed areas, damage to homes and property caused by these storms is much more devastating than in south Louisiana, where a large buffer of coastal wetlands still separates towns and cities from the Gulf of Mexico. Coastal wetlands absorb enormous amounts of water and dissipate wave energy that would otherwise allow storms to do severe damage inland. Placing a monetary value on the storm-buffering benefits that wetlands provide is not easy; however, the coastal development infrastructure being protected is undoubtedly valued in the billions of dollars (Coreil 1994).
By serving as a buffer to destructive marine forces and the episodic impact of storms, Louisiana’s coastal wetlands help to protect the vast infrastructure of nationally significant oil and gas facilities. An estimated 21% of the nation’s natural gas supply, valued at $7.4 billion per year, originates from Louisiana wetlands. Additionally, petroleum products valued at $30 billion per year are produced in Louisiana coastal zone refineries (LCWCRTF 1993). Furthermore, the wetlands protect the extensive network of pipelines that is necessary to transfer large amounts of natural resources. Secure pipelines and supply bases in the coastal wetlands make low-cost production on the outer continental shelf possible. This infrastructure provides a vital energy link to population centers in other parts of the country. The loss of wetlands makes these facilities more susceptible to marine forces for which they were not designed to withstand.
Louisiana’s coastal wetlands provide protection from storms for more than 400 million tons of water-borne commerce, the largest in the nation within the coastal channels each year (figure 7). Those wetlands contain ten major federal navigation channels that provide access to port facilities across the state. These waterways include the Gulf Intracoastal Waterway, Mississippi River Gulf Outlet, Mississippi River, Barataria Bay Waterway, Lower Bayou Lafourche, Houma Navigation Canal, Atchafalaya River, Freshwater Bayou, Mermentau-Gulf of Mexico Navigation Channel and Calcasieu Ship Channel. New Orleans is located at the gateway to the entire Mississippi River Valley and is one of the nation’s largest deep-draft port complexes. Port facilities located between the mouth of the river and Baton Rouge, handle over 230 million tons of cargo annually, valued at more than $30 billion. The cargoes managed by these port facilities exceed the total volume of commodities handled by all U.S. West Coast port facilities combined and compose approximately 25% of the nation’s total exported commodities (LCWCRTF 1993). This industrial and commercial base is not directly dependent on the coastal wetlands but clearly benefits from their protective role during the storm season. In addition, the culture for many whose livelihoods depend on those industries is closely linked with the vast extent of wetlands.
Known as the "Sportsman’s Paradise," Louisiana holds true to its name as evidenced by the amount of money spent on recreation in the state’s wetlands every year. The vast numbers of fish and wildlife attract thousands of visitors from out of state, as well as Louisiana’s natives, to wetlands for hunting and fishing. Recreational fishermen pursuing wetland-dependent species contribute more than $235 million annually to Louisiana’s economy (Cowan and Turner 1988).
The eco-tourism industry is growing in Louisiana as the nation’s appreciation for the value and beauty of wetlands is increasing. Activities such as boating, watersports, hiking, bird watching, camping and nature photography are very popular in Louisiana. In many rural communities, wetland-related eco-tourism, including swamp tours, is an extremely important economic activity with great potential for growth. In 1991, over $220 million was spent by nonconsumptive wildlife participants (Coreil 1994). These expenditures contribute to the local economy. Eco-tourism allows visitors from the rest of the nation and the world to enjoy Louisiana’s wetlands.