Example of land loss in coastal Louisiana between 1932 and 2011; detail of Port Fourchon area
Coastal erosion in Louisiana is the process of steady depletion of wetlands along the state's coastline in marshes, swamps, and barrier islands, particularly affecting the alluvial basin surrounding the mouth of the Mississippi River. In the last century, coastal Louisiana has lost an estimated 4,833 square kilometers (1,866sqmi) of land, approximately the size of Delaware's land area.[1] Coast wide rates of wetland change have varied from −83.5 square kilometers (−32.2sqmi) to −28.01 square kilometers (−10.81sqmi) annually, with peak loss rates occurring during the 1970's.[1] One consequence of coastal erosion is an increased vulnerability to hurricane storm surges, which affects the New Orleans metropolitan area and other communities in the region. The state has outlined a comprehensive master plan for coastal restoration and has begun to implement various restoration projects such as fresh water diversions, but certain zones will have to be prioritized and targeted for restoration efforts, as it is unlikely that all depleted wetlands can be rehabilitated.
The process of coastal erosion in Louisiana is the result of various factors, including sea level rise; ordinary subsidence of organic materials; deprivation of periodic sediment due to flooding prevention measures; tropical cyclones; oil and gas extraction and infrastructure; navigation infrastructure; and saltwater intrusion.[1] While land subsidence is dominated by Glacial Isostatic Adjustment (GIA),[2][3] sediment compression is next factor further compounding the problem.[4] Sea level rise attributed to global warming, though not a root cause, is also considered a contributing factor and future concern.
Coastal erosion is defined as "the loss of coastal lands due to the net removal of sediments or bedrock from the shoreline."[5] South Louisiana is one of the main places being affected. In 1973, Louisiana State University published “Environmental Atlas and Multi-Use Management Plan for South-Central Louisiana” analyzing the issue and possible solutions.[6] The solutions were not implemented and the issues the report sought to fix are still outstanding.[6]
Estimated Wetland Area Change in Coastal Basins, 1932–2016[1]
Man-made levees, which were designed to protect residents and property adjacent to the river, block spring flood water that would otherwise bring fresh water and sediment to marshes. Swamps have been extensively logged, leaving canals and ditches that allow saline water to move inland. Canals dug for the oil and gas industry also allow storms to move sea water inland, where it damages swamps and marshes. Rising sea levels attributed to global warming have exacerbated the problem. As sea levels continue to rise, the land subsidence rates among Louisiana's coast will also increase.
An extensive levee system aided by locks and dams has been developed in the waterways of the lower Mississippi River.[7] The levees, designed to prevent flooding along the waterways, on one hand, prevent silt from draining into the river yet also prevent it from being distributed into the marshes downriver. With no new accretion and steady subsidence, the wetlands slowly are replaced by encroaching saltwater from the Gulf. As a result of this apparent dilemma, large areas of marsh are being lost to the ocean. Since 1930 water has consumed more than 1,900 square miles (4,900km2) of the state's land. This loss equates to the disappearance of 25 square miles (65km2) of wetlands each year or a football-field-sized area every 30 minutes. This loss can be reversed, at least in some areas, but only with large scale restoration, including the removal of levees to allow the Mississippi River to carry silt into these areas.[8][9]
Prior to the building of levees on the Mississippi River, the wetlands were kept in balance by occasional floods, which filled the area with sediment, and subsidence, the sinking of land. These man-made levees contribute to extensive down-stream flooding and sediment pollution in the Mississippi River Delta. After the levees were built, however, flood sediment flowed directly into the Gulf of Mexico. This subsidence along with the recent sea level rise tipped the balance toward subsidence rather than marsh growth. This, along with the canals built in the area, caused decline of the wetlands and also caused less weakening of and less protection from recent hurricanes such as Hurricane Katrina.[10] The Lake Pontchartrain Basin Foundation has developed a comprehensive management plan for the eastern regions of the Louisiana coast, placing emphasis upon restoration of riverine habitats, cypress swamps and fringing marsh. This could be a model applied to other coastal regions.
Subsidence may be due to other factors as well. Some observers blame the direct effects of oil and gas extraction, known as fracking. They believe the removal of subsurface materials, such as oil, hastened the rates of land subsidence. They contend that, as billions of barrels of oil and saltwater and trillions of cubic feet of gas were removed from the subterranean structures in which they had accumulated over millions of years, these structures lost their ability to support the weight of the earth above. As these structures slowly collapsed, the soil above gradually subsided. The wetlands on the surface began to sink into the Gulf waters. Others argue that subsidence is a natural process in deltas, as sediments compress, and that the real problem is the lack of flood waters that would normally deposit new layers of sediment.[11][12] The role of hurricanes is also a matter of disagreement; some studies show that hurricanes actually build elevation in marshes.[13] A new and important factor is the rising sea levels associated with global warming.[14]
Another factor that damaged wetlands was large-scale logging, particularly the extensive logging of cypress forests in the early 1900s.[15] One early logger described it this way: "We just use the old method of going in and cutting down the swamp and tearing it up and bringing the cypress out. When a man's in here with all the heavy equipment, he might as well cut everything he can make a board foot out of; we're not ever coming back in here again."[16]:103 This logging often required construction of canals, which, once the logging was finished, allowed salt water to enter the wetlands and prevent regeneration of the cypress.[8]
As if these problems were not enough, the introduction of nutria, an invasive wetland rodent from South America, in the 1930s provided an entirely new species of grazing mammal. Although only a few escaped, there are now millions.[17] Natural grazing by muskrat was now accelerated by grazing from nutria. By removing plants, nutria cause both loss of vegetation and, perhaps more seriously, a loss of dead organic matter which would otherwise accumulate as peat and raise the level of the marsh.[18] One of the most important natural controls on nutria is predation by large alligators, which may provide a useful tool for biological control of nutria, thereby reducing their impact on marshes.[19]
Terrebonne and Lafourche Parishes in Southeast Louisiana, with a combined population of 209,136, are at great risk of going underwater due to coastal erosion.[20][21] It is estimated with the current rate of erosion, 75 square kilometers a year, these areas and their surrounding parishes will be underwater within fifty to eighty years.[20]
Erosion from heavy storms, climate change, and human interference with the environment contribute to erosion in South Louisiana.[5] The Gulf of Mexico brings heavy rains and hurricanes to this region. This loosens the sediments in the marshes, and along the Mississippi River, allowing them to be carried away by the water. Human interference would be the diversion of the Mississippi river and other rivers. The diversion causes sediments to be deposited in places other than where they normally would be.[22]
Oil and gas industry
Oil and gas extraction in the Louisiana coastal zone began in 1926 and peaked in 1970 with 72 million barrels of oil.[23] Although most oil and gas extraction has shifted offshore to the outer continental shelf, the construction of channels and pipelines continues in the wetlands.[23] Infrastructure, such as canals, pipelines, and other features, contributes to wetland loss not only through direct removal of material but also by altering hydrologic flow: salt water may more easily intrude, and wave action may propagate through canals.[1] For example, the construction of the now-closed Mississippi River Gulf Outlet (MRGO) introduced salt water into freshwater and intermediate marshes in St. Bernard Parish, which is adjacent to New Orleans, and facilitated significant erosion.[24] In addition to the canals themselves, spoil banks also alter local hydrology.[23]
What was then the Orleans Levee Board, now the Southeast Louisiana Flood Protection Authority operating as the East and West divisions, filed a lawsuit in July 2013 against 97 oil and gas companies for damages, claiming the 50 miles of marsh swamps, with stands of cypress that buffered Gulf storms, were "shredded by oil industry canals". It was considered to be an "entire ecosystem tanking", the "largest ecological catastrophe in North America since the dust bowl", and "a wetland dying".[citation needed] “When you talk about dredging those canals, yes, it now appears to have been a pretty stupid thing to do.... But no one ever dreamed it would be an issue or that the coast would waste away.” —John Laborde, Founder, Tidewater Marine, 2010.[citation needed] This was not a new hypothesis as Percy Viosca, a Tulane graduate ultimately fired by then-Governor Long and brought back under another administration, stated in 1925, “Man-made modifications in Louisiana wetlands, which are changing the conditions of existence from its very foundations, are the result of flood protection, deforestation, deepening channels[,] and the cutting of navigation and drainage canals.”, and concluded by stating that the “time is ripe for an enormous development of the Louisiana wetlands along new and [more] intelligent lines.”[25]
Consequences
The many benefits of the wetlands found in this region were not recognized by a majority of policy makers early in the 20th century. Wetlands provide many important ecological services including, fisheries production, resting areas for migratory species, carbon storage, water filtration and enhanced disagreement over the relative importance of these factors, not to mention flood control.[26]
Southeastern Louisiana's disappearing wetlands have a broad impact ranging from cultural to economic. Commercial fishing in Louisiana accounts for more than 300 million dollars of the state's economy. More than 70% of that amount stems from species such as shrimp, oysters and blue crabs that count on the coastal wetlands as a nursery for their young. Annually Louisiana sells more than 330,000 hunting licenses and 900,000 fishing licenses to men and women who depend on the wetlands as a habitat for their game. Additional recreational activities such as boating, swimming, camping, hiking, birding, photography and painting are abundant in wetland areas. Wetlands host a variety of trees such as the bald cypress, tupelo gum and cottonwood. Other plants such as the dwarf palmetto and wax myrtle and submerged aquatic plants such as Vallisneria and Ruppia are native to Louisiana wetlands. Wetland plants act as natural filters, helping to remove heavy metals, sewage, and pesticides from polluted water before reaching the Gulf of Mexico. Animal species native to these areas include osprey, anhinga, ibis, herons, egrets, manatees, alligators, and beavers. Although there are several naturally occurring forces that adversely affect the wetland regions of Louisiana, many believe it is human intervention that has caused the majority of the decline.[10]
As the wetlands disappear, more and more people are leaving wetland areas.[27] Since the coastal wetlands support an economically important coastal fishery, the loss of wetlands is adversely affecting this industry.
Another consequence of coastal erosion is the loss of sandbars off the coast of Louisiana. The sandbars off of Louisiana's coast protect Louisiana's coast from storm surges and high-speed winds that accompany hurricanes from the Gulf of Mexico. In the past, these sandbars have helped minimize the damage to Louisiana's coast from hurricanes. However, as coastal erosion continues to cause these sandbars to degrade, the damage taken by Louisiana's coastline continues to increase.
Because of this loss of Louisiana's coastline, many Louisiana communities are being affected. Some communities are experiencing flooding on a much more regular basis. If this loss of coastline continues, many of these communities will have to relocate. Some communities already have completely located, uprooting everyone who lives there. Therefore, coastal erosion is having a much greater effect on Louisiana residents than many people believe.
There are several projects and proposals to save coastal areas by reducing human damage, some of which have been attempted, including restoring natural floods from the Mississippi. Without such restoration, coastal communities will continue to disappear.[28] One of the primary methods that has been developed are freshwater diversions, which extract water from Mississippi River at strategic locations and transport fresh water and silt from the river through aqueducts and then pump and distribute them into nearby estuaries.[29] Other currently active projects include hydrologic restoration, marsh creation, ridge restoration, and risk reduction to human structures, described below.[30]
The freshwater diversion process invigorates freshwater plant life and re-introduces silt into the estuaries.[29][31] Freshwater diversions have not been without controversy and have encountered some opposition, primarily from oyster harvesters who believe that the current high level salinity is needed in their state-licensed zones in order to maintain healthy production.[32] Another method of coastal restoration is the direct planting of new marsh grasses and other forms of sustainable plant life into affected areas.[33] There is the practice of seeding, which may be turn out to be more productive than direct planting, which often entails the dropping large amounts of seeds from crop-dusters intended to grow into freshwater plants.[33]Mangrove seeds have been tried because when grown they have the benefit of reducing marsh water salinity.[33] Transporting already-dredged material from the Mississippi river to marshes, swamps, and barrier islands is also an option.[34] Some have proposed the removal of river levees in certain low-populated areas to allow fresh water and silt dispersion into marshes, though this method is controversial and has yet to be attempted.
The Louisiana Coastal Protection and Restoration Authority has developed a master plan which outlines the state's strategy for achieving future coastal restoration as well as flood protection. The plan must be updated every six years; the 4th edition was released in 2023.[35][30] Current Louisiana law stipulates that all oil and gas revenue royalties collected by the state go towards coastal restoration.[36] However, under present arrangements with the federal government, Louisiana is only able to receive a small percentage of royalties, while the rest go to the federal government.[36] Since 2018, Louisiana has been able to receive 37.5 million dollars from all new leases, though pre-existing leases still fall under the prior state/federal revenue sharing arrangement.[36] Proceeds from part of the BP Deepwater Horizon oil spill lawsuits and federal fines have also gone towards coastal restoration.[36]
One way to combat coastal erosion is to try and plant more vegetation in Louisiana's wetlands. The roots of plants help hold soil in place and stop the soil from eroding. By adding more vegetation to the wetlands, the soil can be made more firm and less likely to erode. However, salt water intrusion kills many of these plants, thus solutions are needed to help protect planted vegetation.
Another way to combat coastal erosion is to create seawalls and breakwaters. Seawalls are manmade barriers that are erected to keep seawater from reaching the coast. Because the seawater is unable to reach the coast, the water is unable to erode the coastline, thus preventing coastal erosion. Breakwaters function much like seawalls, except that they are not manmade; they are made from large formations of rocks stacked near each other. They are not as effective as seawalls in stopping water from reaching the coast, however, they allow seawater to bring sediment within the barrier, but stop the retreating water from removing sediment, thus helping coastlines build up and replenish.
Estimates are that the area will continue to erode, in part due to a dearth of plant nutrients.[37] Solutions are numerous; however, governments and organizations have problems implementing them.[38] Industry, navigation, and flood control are factors that have to be taken into account with the solutions. One of the most drastic solutions would be diverting the Mississippi river to flow into its delta. A shift in industry locations, navigation, and populations would allow the wetlands to be restored with less interference. Alternatively, increasing sustainability standards would allow the issue to be resolved quicker. Creating more ecologically friendly infrastructure in the areas would allow the marshes to grow and the soil would strengthen.
A swamp is a forested wetland. Swamps are considered to be transition zones because both land and water play a role in creating this environment. Swamps vary in size and are located all around the world. The water of a swamp may be fresh water, brackish water, or seawater. Freshwater swamps form along large rivers or lakes where they are critically dependent upon rainwater and seasonal flooding to maintain natural water level fluctuations. Saltwater swamps are found along tropical and subtropical coastlines. Some swamps have hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodic inundation or soil saturation. The two main types of swamp are "true" or swamp forests and "transitional" or shrub swamps. In the boreal regions of Canada, the word swamp is colloquially used for what is more formally termed a bog, fen, or muskeg. Some of the world's largest swamps are found along major rivers such as the Amazon, the Mississippi, and the Congo.
Grand Isle is a town in Jefferson Parish in the U.S. state of Louisiana, located on a barrier island of the same name in the Gulf of Mexico. The island is at the mouth of Barataria Bay where it meets the Gulf. The town of Grand Isle is statistically part of the New Orleans−Metairie−Kenner metropolitan statistical area, though it is not connected to New Orleans' continuous urbanized area.
Lake Pontchartrain is an estuary located in southeastern Louisiana in the United States. It covers an area of 630 square miles (1,600 km2) with an average depth of 12 to 14 feet. Some shipping channels are kept deeper through dredging. It is roughly oval in shape, about 40 miles (64 km) from west to east and 24 miles (39 km) from south to north.
The Pearl River is a river in the U.S. states of Mississippi and Louisiana. It forms in Neshoba County, Mississippi from the confluence of Nanih Waiya and Tallahaga creeks, and has a meander length of 444 miles (715 km). The lower part of the river forms part of the boundary between Mississippi and Louisiana.
Pointe à la Hache is a census-designated place (CDP) and unincorporated community in Plaquemines Parish, Louisiana, United States. Located on the east bank of the Mississippi River, the village has been the seat for Plaquemines Parish since the formation of the parish. As of the 2020 census, its population was 183, less than half its 1930 population. It suffered severe damage from Hurricane Katrina in 2005 and Tropical Storm Lee in 2011.
The Mississippi River–Gulf Outlet Canal is a 76 mi (122 km) channel constructed by the United States Army Corps of Engineers at the direction of Congress in the mid-20th century that provided a shorter route between the Gulf of Mexico and New Orleans' inner harbor Industrial Canal via the Intracoastal Waterway.
Lake Borgne is a lagoon of the Gulf of Mexico in southeastern Louisiana. Although early maps show it as a lake surrounded by land, coastal erosion has made it an arm of the Gulf of Mexico.
The Mississippi River Delta is the confluence of the Mississippi River with the Gulf of Mexico in Louisiana, southeastern United States. The river delta is a three-million-acre area of land that stretches from Vermilion Bay on the west, to the Chandeleur Islands in the east, on Louisiana's southeastern coast. It is part of the Gulf of Mexico and the Louisiana coastal plain, one of the largest areas of coastal wetlands in the United States. The Mississippi River Delta is the 7th largest river delta on Earth (USGS) and is an important coastal region for the United States, containing more than 2.7 million acres of coastal wetlands and 37% of the estuarine marsh in the conterminous U.S. The coastal area is the nation's largest drainage basin and drains about 41% of the contiguous United States into the Gulf of Mexico at an average rate of 470,000 cubic feet per second.
Hurricane preparedness in New Orleans has been an issue since the city's early settlement because of its location.
The wetlands of Louisiana are water-saturated coastal and swamp regions of southern Louisiana, often called "Bayou".
The Atchafalaya Basin, or Atchafalaya Swamp, is the largest wetland and swamp in the United States. Located in south central Louisiana, it is a combination of wetlands and river delta area where the Atchafalaya River and the Gulf of Mexico converge. The river stretches from near Simmesport in the north through parts of eight parishes to the Morgan City southern area.
Isle de Jean Charles is a narrow ridge of land situated in Terrebonne Parish, Louisiana. For over 170 years, it has been the historical homeland and burial ground of the state-recognized tribe of the Isle de Jean Charles Band of Biloxi-Chitimacha-Choctaw Indians. Residents of the Island have long been threatened by Louisiana's coastal erosion, as coastal Louisiana loses a landmass the size of Manhattan every year. In 1955, Isle de Jean Charles consisted of over 22,000 acres (8,900 ha) and has since lost about 98% of its land due to saltwater intrusion, and subsidence. In January 2016, the state of Louisiana received substantial funding from the United States Department of Housing and Urban Development to fund a community resettlement that was designed.
The Louisiana Coastal Protection and Restoration Authority (CPRA) is a governmental authority created by the Louisiana State Legislature in the aftermath of Hurricanes Katrina and Rita to combat the ongoing erosion of Louisiana's coast. The CPRA reports to the Office of the Governor of Louisiana. The organization takes advantage of both federal and state funding of around $1 billion annually.
Caernarvon is an unincorporated community in St. Bernard Parish, Louisiana, United States. The name of the community is from a plantation originally located here. The plantation's name is widely believed to be from a similarly named town and castle in Wales. Names of antebellum plantations in the American South were often reflective of European roots and aspirations of grandeur; two upriver Mississippi River plantations, Nottoway near White Castle, Louisiana, and Sans Souci near Osceola, Arkansas, are two examples of this tradition.
The Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) is a 1990 United States federal law that provides funds for wetland enhancement. The law is implemented by federal and state agencies, focusing on restoration of lost wetlands of the Gulf Coast, as well as protecting the wetlands from future deterioration. The scope of the mission is not simply for the restoration of wetlands in Louisiana, but also the research and implementation of preventative measures for wetlands preservation
The Mississippi Alluvial Plain is a Level III ecoregion designated by the Environmental Protection Agency (EPA) in seven U.S. states, though predominantly in Arkansas, Louisiana, and Mississippi. It parallels the Mississippi River from the Midwestern United States to the Gulf of Mexico.
Land loss is the term typically used to refer to the conversion of coastal land to open water by natural processes and human activities. The term land loss includes coastal erosion. It is a much broader term than coastal erosion because land loss also includes land converted to open water around the edges of estuaries and interior bays and lakes and by subsidence of coastal plain wetlands. The most important causes of land loss in coastal plains are erosion, inadequate sediment supply to beaches and wetlands, subsidence, and global sea level rise. The mixture of processes responsible for most of the land loss will vary according to the specific part of a coastal plain being examined. The definition of land loss does not include the loss of coastal lands to agricultural use, urbanization, or other development.
Salvador Wildlife Management Area is a protected area in St. Charles Parish Louisiana covering a combined total of over 36,000 acres (15,000 ha). The WMA is located 11 miles (18 km) south of New Orleans, Louisiana, and provides habitat for many species of animal and plant life with hunting, fishing, and boating as the predominant activities. Commercial fishing or harvesting is not allowed.
Sedimentation enhancing strategies are environmental management projects aiming to restore and facilitate land-building processes in deltas. Sediment availability and deposition are important because deltas naturally subside and therefore need sediment accumulation to maintain their elevation, particularly considering increasing rates of sea-level rise. Sedimentation enhancing strategies aim to increase sedimentation on the delta plain primarily by restoring the exchange of water and sediments between rivers and low-lying delta plains. Sedimentation enhancing strategies can be applied to encourage land elevation gain to offset sea-level rise. Interest in sedimentation enhancing strategies has recently increased due to their ability to raise land elevation, which is important for the long-term sustainability of deltas.
Terrebonne Basin is an abandoned delta complex, in Terrebonne Parish, Louisiana. The area is identified by thick sections of unconsolidated sediments that are undergoing dewatering and compaction which contributes to high subsidence. There is a network of old distributary ridges, associated with past distributaries of the Mississippi River, extending south from Houma, Louisiana into the Gulf of Mexico.
References
1 2 3 4 5 Couvillion, B.R., Beck, Holly, Schoolmaster, Donald, and Fischer, Michelle, 2017, Land area change in coastal Louisiana 1932 to 2016: U.S. Geological Survey Scientific Investigations Map 3381, 16 p. pamphlet, https://doi.org/10.3133/sim3381. This article incorporates text from this source, which is in the public domain.
↑ Wolstencroft, M.; Shen, Zh.; Törnqvist, T.; Milne, G.; Kulp, M.; 2014. Understanding subsidence in the Mississippi Delta region due to sediment, ice, and ocean loading. Insight from geophysical modelling" [in:] Journal of Geophysical Research: Solid Earth, 119, 3838-3856, 31 Mar 2014; published online: 28 Apr 2014, http://www.tulane.edu/~tor/documents/JGR2014.pdf
↑ Törnqvist, T.; Wallace, D.; Storms J.; Wallinga, J.; van Dam, R.; Blaauw, M.; Derksen, M.;, Klerks, C.; Meijneken, C.; Snijders, E., 2008. Mississippi Delta subsidence primarily caused by compaction of Holocene strata, [in:] Nature Geoscience 1, 173 - 176 (2008), Published online: 17 February 2008 | doi:10.1038/ngeo129 http://www.nature.com/ngeo/journal/v1/n3/full/ngeo129.html
↑ Thomas, D. et al., 2016. The Dictionary of Physical Geography, Fourth Edition, Wiley Blackwell, p. 471
↑ Reuss, M. (1998). Designing the Bayous: The Control of Water in the Atchafalaya Basin 1800–1995. Alexandria, VA: U.S. Army Corps of Engineers Office of History.
1 2 Keddy, P.A.; Campbell, D.; McFalls, T.; Shaffer, G.; Moreau, R.; Dranguet, C.; Heleniak, R. (2007). "The wetlands of lakes Pontchartrain and Maurepas: past, present and future". Environmental Reviews. 15: 1–35. doi:10.1139/a06-008.
↑ Turner, R. E. and Streever, B. 2002. Approaches to Coastal Wetland Restoration: Northern Gulf of Mexico. The Hague, the Netherlands: SPB Academic Publishing.
1 2 Tidwell, Mike. The Ravaging Tide: Strange Weather, Future Katrinas, and the Coming Death of America's Coastal Cities, Free Press, 2006. ISBN0-7432-9470-X
↑ Boesch, D. F., Josselyn, M. N., Mehta, A. J., Morris, J. T., Nuttle, W. K., Simenstad, C. A., and Swift, D. P. J. (1994). Scientific assessment of coastal wetland loss, restoration and management in Louisiana. Journal of Coastal Research, Special Issue No. 20.
↑ Liu, K. and Fearn, M. L. (2000). Holocene history of catastrophic hurricane landfalls along the Gulf of Mexico coast reconstructed from coastal lake and marsh sediments. In Current Stresses and Potential Vulnerabilities: Implications of Global Change for the Gulf Coast Region of the United States, eds. Z. H. Ning and K. K. Abdollhai, pp. 38–47. Baton Rouge, LA: Franklin Press for Gulf Coast Regional Climate Change Council.
↑ Norgress, R. E. (1947). "The history of the cypress lumber industry in Louisiana". Louisiana Historical Quarterly. 30: 979–1059.
↑ Van Holmes, J. (1954). "Loggers of the unknown swamp". Saturday Evening Post. 226: 32–33, 102–105.
↑ Atwood, E. L. (1950). "Life history studies of the nutria, or coypu, in coastal Louisiana". Journal of Wildlife Management. 14 (3): 249–65. doi:10.2307/3796144. JSTOR3796144.
↑ Keddy, P.A. 2000. Wetland Ecology: Principles and Conservation. Cambridge University Press, Cambridge, UK. 614 p. P. 163-165.
↑ Keddy, P.A., L. Gough, J.A. Nyman, T. McFalls, J. Carter and J. Siegrist. 2009. Alligator hunters, pelt traders, and runaway consumption of Gulf coast marshes: A trophic cascade perspective on coastal wetland losses. p. 115-133 in B.R. Silliman, E.D. Grosholz, and M.D. Bertness (eds.) Human Impacts on Salt Marshes. A Global Perspective. University of California Press, Berkeley, CA.
↑ "Closing the Mississippi River Gulf Outlet: Environmental and Economic Considerations." Coastal Wetlands Planning Protection and Restoration Act. Louisiana State Government. Web. 27 Feb 2013. <http://lacoast.gov/new/Data/Reports/ITS/MRGO.pdf>
↑ Tulane Environmental Law JournalThe Reckoning: Oil and Gas Development in the Louisiana Coastal Zone (pp. 192-198)- Retrieved 2017-11-12. Note: Quotes are from pages 194 and 198 respectively.
↑ Tidwell, Michael. Bayou Farewell: The Rich Life and Tragic Death of Louisiana's Cajun Coast. Vintage Departures: New York, 2003 ISBN978-0-375-42076-4.
↑ Boesch, D. F., Josselyn, M. N., Mehta, A. J., Morris, J. T., Nuttle, W. K., Simenstad, C. A., and Swift, D. P. J. (1994). "Scientific assessment of coastal wetland loss, restoration and management in Louisiana", Journal of Coastal Research, Special Issue No. 20.
↑ "Caernarvon Freshwater Diversion Project". GulfBase.org. Harte Research Institute for Gulf of Mexico Studies at Texas A&M University-Corpus Christi. Archived from the original on September 7, 2015. Retrieved September 6, 2015.
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