Coastal Wetlands

Coastal Wetland                 A rich variety of freshwater, saltwater, and brackish environments and habitats characterized by wet and spongy soils located in the transition zone between dry land and the ocean that comprise the most biologically diverse of all ecosystems. Coastal wetlands may be known as bayou, wetland hardwood forests and swamps, seagrass beds, coastal marshes or ponds, mangrove swamp, tidal flat, tidal marsh, salt marsh, bogs, and many others. Whatever their local or regional names, those areas are rich in wildlife and are critical nesting, spawning, and nursery grounds for resident and migratory birds, fish, amphibians, reptiles, mammals, shellfish and crustaceans. They easily constitute one of the most sensitive, valuable and productive habitats on Earth.

Author’s Rant: All across the U.S. coastal wetlands have been disappearing for the last 100 years. Rather than that process being slowed over the last 60 years as a result of rising environmental attitudes and practices, the rate of decline and destruction has been accelerating. The systemic and institutional failure of any U.S. governmental agency to protect those fragile environments is nothing less than appalling and heartbreaking. The agency most directly involved in those losses is the U.S. Army Corps of Engineers, which is charged under the law with their protection and regulation. So, why coastal wetlands are in decline? Here’s but one specific example.

The delta of the Mississippi River in Louisiana contains about 40 percent of the coastal wetlands in the coterminous U.S. No other wetland comes close to its size or environmental significance. That complex web of natural levees, natural ridges, freshwater wetlands, tidal marshes, beaches, shifting bars, and barrier islands was created by the enormous sediment load deposited by the Mississippi River over thousands of years. The sediment load was largely from three main river systems that fed into the Mississippi: the Missouri, Ohio, and the Arkansas. So, historically the delta area experienced several opposing forces. The deposition of mud, silt, and sand built up and extended the land into the Gulf of Mexico, renewed the soil, prevented salt water intrusion and encroachment, and created an interrelated system of barrier islands, sand bars, and wetlands that resulted in an extraordinarily high level of natural productivity. At the same time, natural coastal erosion and marine processes tore down and carried away many of the deposited materials. Although those erosional processes didn’t come close to making the game even, they never stopped; year after year the waves and currents continued working and reworking the sediments. Second, the entire coastal area of Louisiana, Mississippi, and Alabama was sinking isostatically under the enormous weight of the deltaic deposits. Since that process was also very slow the delta grew as sediments continued to be deposited.

Barrier islands lying in front and to the side of the Mississippi River delta plain buffer the effects of ocean waves and currents on associated estuaries and wetlands. But today those barrier islands are eroding at a rate of up to 60 feet per year. As the barrier islands disintegrate, the vast system of sheltered wetlands are exposed to the full force of wave action, salinity intrusion, tropical storm and hurricane surge, tidal currents, and sediment transport that combine to accelerate wetland deterioration. The result is that today the barrier islands are disappearing, coastal erosion has increased, the shoreline is retreating, and the delta’s wetlands are being swallowed by the Gulf at the alarming rate of over 25,500 acres or 40 square miles each and every year. That wetland loss is about 80 percent of the total wetland loss recorded in the United States and is a process that not only is accelerating and but is also predicted to continue with marginal relief into the foreseeable future. If that rate of loss is not slowed, by the year 2040 an additional 800,000 acres of wetlands will have been eaten by erosion and subsidence As a direct result, in certain areas the Louisiana shoreline will have moved inland as much as 33 miles.

Louisiana’s coastal wetlands extend as much as 80 miles inland and along the sea shore for about 180 miles. The State has lost over 1.2 million acres or 1,900 square miles of that fragile coastal habitat since the 1900s. Although not all Louisiana’s coastal wetlands are receding, in fact some areas are stable and others are growing, at the present rate of net loss all of that crucial habitat will have disappeared in about 200 years.

So, what’s really happening? The answer is neither complicated nor difficult to understand. The critical process is human alteration of a natural system. As people streamed across America, settling the land, they cried out for government help when natural disasters struck, like floods in the Midwest, South, and Great Plains. Congress responded by having the U.S. Army Corps of Engineers build levees, dikes, dams, and reservoirs as flood control measures. The once mighty rivers like the Mississippi, Missouri, Ohio, Tennessee, and Arkansas were tamed by a system of dams and levees that continue upstream for nearly 1,200 miles. Their sediment loads decreased dramatically as mud and silt were dropped in the reservoirs created by the upstream dams. Today, the lower Mississippi River is nothing but an artificial channel contained by levees and embankments that prevent flooding and ensure that its sediment load is not distributed across the floodplain, where it would create and replenish wetlands, but instead is sped straight to the mouth of the River and into the deep waters of the Gulf. As a direct result of that human intervention, insufficient sediment is being deposited in the wetlands and without that replenishment, they are disappearing under the continuing and unabated assault of natural coastal erosion and subsidence.

In 1990, the federal Coastal Wetland Planning, Protection Restoration Act, (PL-101-646, Title 111, abbreviated as CWPPRA and widely known as the “Breaux Act”), provided authorization and funding for a multi-agency task force to curtail wetland losses. It took that task force, which included the State of Louisiana and four Federal agencies charged with restoring and protecting the remainder of Louisiana’s valuable coastal wetlands, eight years of extensive studies before a new coastal restoration plan was adopted in 1998. The underlying principles of the new plan, Coast 2050: Toward a Sustainable Coastal Louisiana, are to restore or mimic the natural processes that built and maintained coastal Louisiana. The Plan calls for basin-scale action to restore more natural hydrology and sediment introduction processes and proposes ecosystem restoration strategies that would result in efforts larger in scale than any that have been implemented in the past. The largely unappreciated irony is that the federal government, through environmentally disastrous actions of the Corps of Engineers, has taken away millions of tons of natural resource treasures with one hand and returns ounces with its other hand, and then claims to be solving the problem. Which leaves most objective observers more than a little cynical and bitter.

Make no mistake, at heart the disappearance of coastal wetlands is not a natural environmental problem. The crisis is cultural in nature and goes directly to the way American politics and government work. Few Americans have more than a passing interest in the natural environment. Unless millions of voters experience a drastic change of heart and begin demanding change, nothing will happen. But you have to remember we’re talking about Louisiana where politics is a game played for real. Second, wetlands and swamps don’t vote. Period. More importantly, they don’t contribute millions of dollars to political campaigns, as do agribusinesses, barge companies, chemical firms, oil refineries, and urban developers. Until that situation changes, coastal and other wetlands will continue to disappear at staggering rates while no one listens to the scientists or to the fishermen who daily see their livelihood disappearing.

Additional Author’s Rant: It is possible that that wetlands restoration situation was given an enormous boost in late August, 2005, when Hurricane Katrina savaged the Gulf Coast and dealt New Orleans a nearly fatal blow, which came at least in part because of a Presidential Administration that for three years running diverted many millions of dollars from the New Orleans Corps of Engineers budget for levee repair and strengthening and used that money in the war effort overseas. The initial word from Congress was that the coastal wetlands restoration effort would be strengthened (Katrina’s damage to the natural environment may be partially revealed in the damage done to the offshore Chandeleur Island chain, which lost up to one-half of its pre-storm land mass). But only time will tell if people will become distracted and the Katrina disaster disappears from the front page and falls into the great black hole of public indifference, and we are reminded yet again by the actions of our elected leaders that the road to Hell is paved with good intentions.

Real World Problem: In 2003, former petroleum geologist Robert Morton, who at that time was working for the U.S. Geological Survey, noticed that the highest rates of wetland loss in coastal Louisiana occurred during or just after the period of peak oil and natural gas production in the 1970s and early 1980s. After studying available data, Morton concluded that that coastal subsidence was related to the removal of millions of barrels of oil, trillions of cubic feet of natural gas, and tens of millions of barrels of saline formation water associated with the near-shore petroleum deposits. That massive removal of petroleum resources and related water led directly to regional depressurization, slippage along nearby subsurface faults, and induced subsidence of the land above. The great difficulty is that if Morton is right, no amount of coastal wetland restoration efforts will be effective in those areas as long as gas and oil are being removed in large quantities. If that is the case, land subsidence will continue to characterize southernmost Louisiana as will the disappearance of coastal wetlands. And who out there thinks we will voluntarily stop oil and gas production in coastal Louisiana?

Real World Examples: approximately 81 percent of coastal wetlands in the continental U.S. are in the Southeast and Louisiana has well over half of those. Other coastal wetlands of national significance are located in Florida around Choctawhatchee Bay, Apalachicola Bay, northeastern Florida between the St. Mary’s and St. John’s Rivers, Cape Canaveral, Tampa Bay, Biscayne Bay, and Florida Bay. The Paraná Delta in Argentina and the area around Lake Maracaibo, Venezuela, are two of the larger coastal wetlands in South America. If you’re in southern France you might enjoy visiting the Camargue, a fascinating wetland between the Mediterranean Sea and the two arms of the Rhône River delta, Western Europe’s largest.