MISSISSIPPI COASTAL LANDSCAPE USE

ECONOMIC DEVELOPMENT CAUSING UNINTENTIONAL CHANGE TO A COASTAL LANDSCAPE

The Missippi River Delta has a strong economy which relies heavily on tourism and recreational activites such as fishing, hunting and wildlife

There are a number of major industries in the Mississippi River Delta that drive the local and national economy including:

OIL AND GAS

  • 1/6th of the Louisiana workforce is employed in the oil and gas indstury

  • Louisiana services 90% of the offshore oil rigs in the Gulf of Mexico providing 16-18% of the country’s oil supply

  • Natural gas provides strong economic indsutry for the Mississippi River Delta

  • Louisiana produces over 1/10th of US natural gas supplies and delievers gas to the entire nation of the Gulf of Mexico

SHIPPING AND PORTS

  • Mississippi River Delta’s ports are some of the most active and economically busy ports in the entire nation

  • Five of the US’s largest ports are located in Louisiana

  • Port of South Louisiana is the largest port in the US by tonnage and the fourth largest in the world

  • Louisiana’s river ports supply around 270,000 jobs and bring over $32.9 bn annually to the state’s economy

FISHERIES

  • Commercial and recreational fishers are economically, culturally and historically important for the Louisiana coast

  • Provide a way of life for many who live in Louisiana

  • Has the second largest commercial fishery in the US by weight

  • Contains 7 of the top 50 seafood landing ports in the US

  • Gulf region provides 33% of the nation’s seafood harvest

TOURISM

  • Rich in resources that provide opportunties for tourists to enjoy the Mississippi River Delta

  • Eco-tourism activities like recreational fishing to traditional tourism activities such as Gulf Coast restaurants that feature local seafood

  • Thousands of tourists come every year to participate in the diversity of culturally unique events in the region

IMPACTS OF ECONOMIC DEVELOPMENT ON THE DELTA ON PROCESSES AND FLOWS OF MATERIAL AND ENERGY

  • Has experienced natural processes of growth and retraction as a result of sediment deposition from the river

  • The processes of land loss have far surpassed the river’s land-building properties due to a number of factors

  • Natural causes like hurricanes and other effects of climate change

  • Suffers from lack of sedimentation due to the levee systems, navigation canals and other man-made structures within the region - structures have proven detrimental to natural land-building power of the river

  • The salt water weakens freshwater ecosystems, making them more vulnerable to destruction by hurricanes and unable to withsatand heavy storm surge

NAVIGATION, GAS AND OIL CANALS

  • Dredging canals was seen as a necessity for companies to create deeper channels for easier navigation and laying of pipelines were placed throughout coastal Louisiana serve around 50,000 oil and gas production facilities

  • According to the report filed by the department of the interior, these actions accounted for 30 to 59% of wetland loss in Louisiana from 1956-1978

  • Dredging also contributes to more serious damage over long time periods of time

  • Increased the erosion and degradation of the Mississippi River Delta by facilitating the creation of open water areas that allow for salt water penetration into freshwater wetlands

  • Port of New Orleans has contributed to the destruction of 27,000 acres of wetlands allowing for salt water to enter freshwater ecosystems

LEVEES

  • Primarily built along the river for flood protection and to provide stabilization of the banks allowing for more reliable navigation

  • Levees, floodways, basin and channel improvement built to improve flood protection

  • Success has come at a high cost for the region’s natural landscapes and ecosystems as the levees sever the connection between the river and the delta

  • Freshwater and sedimenet carried by the river is the fuel needed for land growth within the delta

IMPACTS ON THE DELTA LANDFORMS

  • During 20th century there was a dramatic reversal of the net growth of the Delta

  • High rates of land loss occured with estimates as high as 100km2 per year

  • Multiple factors have been linked to coastal land loss, including elimination of riverine input (sediment not getting to delta)

  • Regional rate of geologic subsidence in the Delta is about 10 mm per year - rate is due to compaction, dewatering and consolidation of sediments

  • When canals are dredged the excavated material is deposited along the side of the canal creating an elevated bank - consist of organic march soil

  • Reduced sediment inputs and lower organic soil formation in the adjacent wetland, exacerbating sediment accretion deficits

  • Shown that as the density of canals in an area increases, the density of natural channels decreases

  • Canals also contribute to water quality problems - tidal currents are stronger through dredged canals than through natural channels, this coupled with wave energy from boat wakes, results in erosion of the banks

  • BP oil disaster in 2010 - resulted in loss of sheltered, stable environment for sediment accretion