Anthropogenic action is wiping out Louisiana bayou

Anthropogenic action has damaged bayou ecosystems over the years

by Lorenzo Ciotti
Anthropogenic action is wiping out Louisiana bayou
© John Moore / Staff Getty Images

The bayou is a typical ecosystem of the Mississippi Delta, in Louisiana. The bayou is made up of marshy expanses that develop between the different arms of the Mississippi River. The waterways form a navigable network that local people have used for centuries and is a typical Louisiana ecosystem, characterized by dense forests and houses on stilts.

The bayou is different from mangrove forests because its water is fresh while the mangrove grows in salt water. In both cases the fauna is numerous and varied with alligators, manatees, dolphins, crustaceans, amphibians and birds such as the heron or the ibis. The habitat is also typical of the mosquito.

Anthropogenic action has damaged bayou ecosystems over the years, being susceptible to pollution such as runoff from nearby urban communities and oil spills given their low location in the watershed. Many bayous have also been swept away by human activities.

The Bayous have experienced trends of land cover loss and conversion to impervious surfaces, which have been associated with influxes of metals such as aluminum, copper, iron, lead, and zinc. Heavy metals in sediments and ultimately bayous waters bioaccumulate in organisms to spread their toxins through various trophic levels.

Mississippi© NASA / Handout Getty Images

Several oil spills have impacted bayou regions, including the 2010 Deepwater Horizon oil spill. This oil spill occurred off the coast of Louisiana and resulted in the deaths of 11 people and the release of over 4 .9 million barrels of oil in the ocean. The bayou wetlands of Bataria Bay, Louisiana have experienced increased shoreline erosion as a direct result of the Deepwater Horizon oil spill.

Anthropogenic action is wiping out Louisiana bayou

This was determined by examining wetland loss rates in the region starting in the year before the oil spill and comparing them to wetland loss rates after the oil spill. The study found significant land loss in regions not affected by wave activity, further demonstrating that land degradation was caused by oil rather than other sources of weathering such as waves and cyclones.

Other notable oil spills affecting the bayou include 4,000 US gallons of oil spilled into a lake near Bayou Sorrel in Louisiana and 20,000 US gallons of oil spilled into the waters of Saint Bernard Parish and adjacent Bayou Bienvenue in Louisiana.

Both incidents occurred in 2022. Oil spills damage bayous as oil is toxic to most animals. In vapor form, the oil causes lung, liver and nervous system dysfunction when inhaled. Ingested oil poses a threat to the digestive tract. Oil dulls feathers and fur, resulting in disruptions to the animal's ability to insulate in colder temperatures. Matted bird feathers lose the properties that help them fly and swim.

Human development activities, such as increases in impervious surfaces, result in faster and more intense flood pulses, providing greater amounts of these nutrients to the ecosystem at a much faster rate. Impervious surfaces include roads, housing developments and parking lots that replace natural vegetation, typically associated with human development and urbanization.