Yr 11 Geography Coursework Illustrating Coastal Erosion In Louisiana

The coastline formed by the Mississippi River is changing continually as part of the never-ending interplay between the forces and processes reshaping and realigning coastal contours and bathymetry. Over millennia, this formative process created Louisiana’s expansive wetlands that once encompassed 7.3 million acres (11,500 square miles) – about the size of Connecticut and Delaware combined – and accounted for at least 40 percent of the nation’s marsh/swamp ecosystems. This natural land-building process, however, has been disrupted by human activities in recent decades—with catastrophic results. Deprived of essential sediments, Louisiana’s coastal wetlands are subsiding and eroding at an alarming pace that casts into doubt humanity’s ability to inhabit and exploit one of the planet’s most economically productive regions.

Erosion alone claims an area the size of a football field every hour, as canals, subsidence, muskrat and nutria eat-outs, salt water intrusion, cold fronts, sea-level rise, and change in the regional hydrology collectively take their toll on this productive habitat. These forces have transformed the state’s once pristine coastal “trembling prairie” into a tattered, shrinking geomorphic artifact. To put this land loss into perspective, Louisiana loses an area greater than New Orleans (180.6 square miles) every 7.2 years.

Alarmed by the disappearance of these wetlands, many concerned citizens now believe that unless corrective measures are initiated soon, the damage to the coastline’s fragile ecosystems will be irreversible. Further, wind and waves are causing the state’s barrier islands to move landward at rates up to 65 feet per year. Between 1900 and 2000, some islands lost nearly half of their surface area; others are completely gone. The region is losing more than a productive estuarine/wetland habitat; the citizens are losing a natural buffer against the full force of a hurricane-induced storm surge. Katrina, for example, generated a surge that approached 30 feet, which is about the height of a three-story building.

Louisiana’s scientific community has diligently investigated and reported the state’s escalating coastal land-loss problem for more than a half-century; yet, coastal erosion has been an urgent political topic only since the first decade of the 21st century. Prior to that time, most policy-makers simply ignored the problem or denied that it even existed. Amazingly, those most affected, the residents of local sea-level communities, simply did not—and, according to a recent Yale University study, still do not—believe their land is washing away. Through their willful blindness, the deniers also generally ignore the impact of increasingly severe natural and manmade catastrophes that repeatedly pummel their environmentally beleaguered homeland: Hurricanes Isadore (2002), Lili (2002), Cindy (2005), Katrina (2005), Rita (2005), Gustav (2008), Ike (2008), Isaac (2012), Harvey (2017), the Macondo/Deepwater Horizon oil spill (2010), the Mississippi River’s “high water” episodes of 2008, 2011, and 2016, and repeated “100-year” rain events, which, in 2016 alone, damaged approximately 146,000 homes in the Louisiana coastal plain.

The once-pervasive notion that Louisiana’s wetlands were too big to fail was — and remains — a widespread misconception. Unfortunately, the ecosystems obscured the darkening reality until an accident of history changed this belief. In the 1960s, President Lyndon Johnson wanted to know if it were possible to divert Mississippi River water to West Texas. The U.S. Army Corps of Engineers issued LSU a feasibility study contract. After investigatory analysis, the research team, under the direction of Dr. Sherwood Gagliano, discovered the Pelican State was losing about 17 square miles of land a year – a number that has fluctuated through time, rising, according to one estimate, to 35 square miles. As a result, the science was clear; diverting the Mississippi would exacerbate the erosion problem dramatically, and the river was not diverted.

Once completed and carefully peer-reviewed, this groundbreaking study was put on a shelf, where it remained largely ignored until later research proved its prescient significance. Beginning in the 1970s and accelerating after 2000, dramatic improvements in computer-aided cartography, GIS, repetitive satellite imagery, photo interpretation and surveying technology, three-dimension models and computer simulations provides better, more accurate measurements of land loss. The 1970 LSU research findings were further reinforced by Dr. Karen Wicker’s 1980 study Environmental Characterization of Terrebonne Parish: 1955-1978, which was one of the first comprehensive land loss assessments of individual coastal parishes. That study morphed into the Atlas of Shoreline Changes in Louisiana from 1853 to 1989, which, in conjunction with a burgeoning number of applied research endeavors, more thoroughly documented Louisiana’s coastal lowlands issues that increasingly endangered the lives and livelihoods of residents supported by wetland resources.

Louisiana has emerged as the national poster child for the dangers environmental changes pose to vulnerable coastal communities. The state’s collective responses to these unprecedented challenges should consequently serve as a national template for addressing environmental Armageddon. The nation must also come to terms with the wetland loss crisis, which until recently was not recognized as a national priority. Recognition at all levels of government was a slow process. In 1990, Louisiana legislators convinced Congress to enact the Coastal Wetlands Planning, Protection and Restoration Act (popularly known at the Breaux Act), which allowed federal funding to go toward wetland protection. Thirty-five years after the initial 1970 study – Louisiana restructured the State’s Wetland Conservation and Restoration Authority to form the Coastal Protection and Restoration Authority (CPRA), the central hub to articulate and development a comprehensive coastal protection plan for Louisiana.

This early momentum continued into the early 21st century, as scientific publications, gray literature, and non-governmental organizations’ outreach efforts have sustained public interest in and concern about continuing land loss. Congress has also approved coastal restoration funds derived from offshore oil and gas revenue produced in the outer continental shelf to help restore and protect the coastal wetlands. A number of bills and measures have been passed and the state in 2009 was entitled to nearly $500 million, a five-fold increase from the $50 million allocated in the early part of the 21st century. Since then, the State Master Plan, and others studies have projected the price tag for rehabilitating the state’s disappearing wetlands from $50 billion to $100 billion. Money is starting to move through the legislative process and projects are moving from the design stage to implementation. This is good news, because the coast continues to disappear and the region’s citizens are increasingly at risk.

— Donald W. Davis, Louisiana State University

 

Coastal erosion is a silent killer that is effectively taking away the life of the Gulf Coast region. Coastal erosion in the Gulf South has been, and will continue to be, an environmental and economic issue for the U.S., especially the Gulf South. If nothing is done to stop the land loss that is occurring daily, the coastline will lose natural barriers to hurricanes, animal habitats and sanctuaries, and the hunting and fishing industry will be affected. Coastal erosion also has a detrimental effect on the oil industry in the region. As a result, the long term effect of Gulf Coast erosion will have a severe impact not only on the Gulf Coast region’s environment, but the national economy.

The Gulf South is home to the fastest eroding estuaries in the world. Over the past 70 years, Louisiana has lost over 1,900 square miles of wetlands and is still losing over 25 to 30 square miles of wet lands each year. That equals out to a football field of land every hour! [1] Louisiana is the state with the greatest amount of land loss due to coastal erosion; however, it is not the only state that is affected by this monstrous environmental “disease.” All of the coastal Gulf South states are losing land to erosion. Coastal erosion is a natural process along the world’s coastlines that occurs through the actions of currents and waves and results in the loss of sediment in some places and deposit in others. However, there has been a dramatic increase in Gulf South coastal erosion over the last two decades.

History of Coastal Erosion in the Gulf South

Coastal erosion is not a new concept. Erosion has taken place for thousands of years all around the world. However, there are many reasons why coastal erosion has increased over the past few years. They include: loss of vegetation, soil erodibility, rainfall intensity, hurricane impact, flooding, as well as runoff and conservation matters. [2] Barrier islands, marshes, and deltas are the most dominant landforms along the coast. These areas are mainly comprised of fine-grained sediments that erode easily in the event of a coastal storm. [3] At a loss rate of 0.326 km2/year, these islands will be converted to submerged sand shoals in 56 years. [4] Over the past decade, the Gulf Coast has been hit by seven major hurricanes, which cause intense rainfall and run-off of loose soil due to lack of vegetation. This does not include tropical storms or tropical depressions, which emit large amounts of rainfall and wind, as well. The future loss outlook is bleak as well, with the expectations of greater losses as a function of global climate change, sea-level rise, and increased intensity of tropical and extra tropical storms. [5] Hurricane-induced erosion seems to have the largest effect; however, they are not the only weather related cause. “Hurricanes are not required for significant coastal change in the Gulf region. Waves and storm surge associated with tropical storms and winter cold fronts provide sufficient energy to put low-elevation beaches and dunes at risk to erosion.” [6] This means that even if the Gulf South region never experiences another hurricane, it is still at risk to weather-induced erosion. Vegetation is another reason for erosion. As plants grow, their roots reach into the ground and root in the soil, making it more stable and less likely to be run off. As coastal erosion continues to happen, its effect on the environment increases.

When assessing coastal erosion, many people tend to think that coastal erosion is a new phenomenon. It took the Mississippi River 6,000 years to build the LA coast. It took man 75 years to wash away a third of it. Experts agree we have 10 years or less to act before the loss becomes irreversible. [7] Before levees were built to establish navigation along the Mississippi River in the early twentieth century, the wetlands were replenished with freshwater and silt during the river’s spring floods and continually rebuilt. [8] Today, due to the diversion of the Mississippi River, these nutrients are deposited in the Gulf of Mexico at the mouth of the Mississippi River. Meanwhile, wetland areas that once had run-off from the Mississippi River, but now are disconnected from the river, are depleting. Without the run-off that replenishes the silt, the wetlands are starving. Similarly, the states that rely on the wetlands to protect them from storms and hurricanes are suffering. Finally, as the wetlands are destroyed, wildlife habitats are also vanishing.

Effect on Environment

The destruction of the wetlands will have a truly negative effect on the wildlife that resides in these areas. With the large amounts of land loss, it will cause migratory birds, along with other species of native birds, to fly further north during their migrating season. This can cause problems with birds repopulating, as well as the hunting industry. Likewise, the birds, fish and other land animals will hurt. These same wetlands provide critical nursery habitat for fish and shellfish that form the basis, not only Louisiana’s fisheries and seafood industry, but also those of the entire Gulf region. When you lose that coastline, you lose the habitat that provides the basis for the region’s fisheries to grow and survive. [9] Deer who reside in the marsh lands will have to evacuate their homes, forcing them to turn towards more heavily populated cities. However, erosion, does not only affect the animals of the region, it affects the plants that are native to the region as well.

As the Gulf Coast recedes due to land loss, the plants, along with the wildlife, disappear as well. As the land disappears, so do the vital nutrients and silt needed for varying plants to grow. It is not just the fact that the Gulf South is losing plants and animals that are crucial for sustaining life, but the fact that it is losing the raw beauty of the land. The coastline will be losing natural plants such as the black mangrove, which adds beauty to the surrounding environment.

Coastal Erosion and the Economy

Coastal erosion today not only affects the environment, but the economy as well. The Gulf Coast’s beaches provide abundant recreational opportunities, contribute substantially to the local economy, and demand the highest real estate values. [10] A total of 158 beach nourishment episodes in 60 locations have been recorded. [11] The Gulf Coast commercial fishing industry provides the U.S. with a huge economic boost. Louisiana, alone, is the most bountiful of the lower 48 states, providing 25% – 30% of the nation’s total catch. [12] If the coast line disappears, this major industry and all of the economic benefits it has for the nation will go with it. Many jobs in the fishing industry will be lost, causing the unemployment rate to rise. If this were to happen, the nation as a whole will see the price for fish rise significantly in years to come.

The Gulf Coast beaches are another thing that will be significantly affected by the loss of coast land. These beaches are extremely vulnerable to hurricanes, as there are minimal barriers in front to help depreciate the hurricane. Overall, the loss of the beaches will cause the local economy of the state to diminish. Many of the social and economic characteristics that influence the vulnerability of individuals and communities along the coast are known at a conceptual level. [13] The scarcity of beach-compatible sand in many areas of the Gulf Coast places an additional premium on the utilization of dredge spoil for nourishment purposes. [14]

Another result of coastal erosion is its effect on the oil industry. If coastal erosion is not slowed down, a possible outcome would be the exposure of pipe lines that were originally underground. This may not sound like a big deal, but as the pipe line is exposed, it is more prone to corrosion and to being punctured. This could cause another oil spill epidemic along with all of the negative effects that come with an oil spill, like it did with the recent BP Deep water Horizon Oil Spill. Due to pipeline exposures, the flow of boats would be disrupted. This will cause pipelines to be more valuable and harder to bring oil to the shoreline.

Current Attempts at Reversing Coastal Erosion

Combined, all of these negative effects will only happen if nothing is done to stop coastal erosion. The plan to conserve wetlands now is to stabilize and ultimately reverse the rate of loss of these critical wetlands. Many Gulf Coast states have implemented plans to help secure the wetlands surrounding their boarders. For instance, in the state of Texas, “the Coast wide Erosion Response Plan was created to identify critical coastal erosion.” [15] This 2009 plan was put in place to identify “current critical erosion areas for prioritized erosion response actions and provide new information that may be used as a reference by local governments in developing their own local erosion response plans.” [16] In what has become an annual event since it became involved in the fight against coastal erosion in 1989, the Louisiana National Guard joined the U.S. Fish and Wildlife Service in placing Christmas trees in eroding areas…the trees collected curbside by the city of New Orleans will help stem erosion and promote silting to help the habitat,the trees then begin new life as saviors of the Louisiana wetlands. Christmas trees are recycled in Bayou Sauvage to fight erosion. Accessed April 17,2014. http://www.nola.com/environment/index.ssf/2012/03/christmas_trees_recycled_in_ba.html

Another act that is in effect is the Breaux Act. The Breaux Act designates a percentage of the money it receives from taxes on fishing equipment, import duties, and motor boat fuels and puts it toward coast restoration in Louisiana. [17] Even though Louisiana’s coast line is the main focus of the act, it still touches other states. The Breaux Act also gives money towards the National Coastal Wetlands Conservation Grant Program and the North American Wetlands Conservation Act which both help to rebuild other depleting coast lines.

Additionally, there are numerous non-governmental groups working on restoring the wetland and barrier islands as well. For example, the Coastal Protection and Restoration Authority, has built over 159 miles of levees, benefitted over $19,500 acres of coastal habitat, and more. [18] This is just one organization at work for the greater cause. If we make aware the general public of this ever growing problem, then more can be done to help protect the wildlife, economy, and people of the Gulf South states.

Conclusion

As discussed, coastal erosion has a devastatingly negative impact on the Gulf South. On a daily basis, land is lost to erosion and habitats are destroyed in the process. All of which has a detrimental effect on the economy of the area and the nation. While projects are in place and new construction has occurred to prevent coastal erosion, there are many questions as to whether it is enough. One thing is for sure, more can always be done and needs to be done to stop the erosion. If it is not stopped, then we will lose precious habitat or worse, our heritage.

Works Cited

  • Couvillion, B.R., Barras, J.A., Steyer, G.D., Sleavin, William, Fischer, Michelle, Beck, Holly, Trahan, Nadine, Griffin, Brad, and Heckman, David. 2011. Land area change in coastal Louisiana from 1932 to 2010: U.S. Geological Survey Scientific Investigations Map 3164, scale 1:265,000, 12 p. pamphlet.
  • Effects of Erosion
  • Erosion Hazard Vulnerability of Us Coastal Counties. http://www.jstor.org/stable/4299493.
  • Relative Sea-Level Rise in Louisiana and the Gulf of Mexico. http://www.jstor.org/stable/4297682.
  • Coastal Education
  • National Assessment of Hurricane- Induced Coastal Erosion Hazards. coastal.er.usgs.gov
  • “Last Chance: The fight to save disappearing coast”. The Times-Picayune.
  • Restore or Retreat. “Restore or Retreat.” Accessed March 11, 2014. http://www.restoreorretreat.org/why-restore/facts-and-figures/.
  • “Louisiana Draws Line in the Sand in Fight Against Coastal Erosion”, http://www.louisianaseafoodnews.com/?s=coastal+erosion
  • “Gulf Coast Vulnerable to Extreme Erosion in Category One Hurricanes: New Model to Help Community Planners, Emergency Managers”
  • Summary of Beach Nourishment along the U.S. Gulf of Mexico Shoreline
  • Restore or Retreat, “Restore or Retreat.” Accessed March 11, 2014. http://www.restoreorretreat.org/why-restore/facts-and-figures/.
  • Social Vulnerability and the Coast
  • Gulf South Beach Nourishment
  • Erosion Response Plans, www.geotexas.gov
  • Erosion Response Plans, www.geotexas.gov
  • Coastal Wetlands Planning, Protection and Restoration Act. “CWPPRA.” Accessed April 28, 2014. http://lacoast.gov/new/Pubs/Report_data/Caring.aspx
  • Coastal Protection and Restoration Authority, “CRPA.” Accessed March 12, 2014. http://coastal.la.gov/our-work/projects/.

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