What human activity is a major contributing factor to coastal erosion in Louisiana?

Dredging and channelization are major contributing factors to coastal erosion in Louisiana primarily because they alter the natural flow of sediment and water in coastal ecosystems. These activities involve deepening or straightening rivers and channels to facilitate navigation, which disrupts the natural deposition of sediment along coastlines.

In healthy coastal systems, sediment is continuously transported and deposited by rivers, helping to build and maintain shorelines. However, when channels are dredged, this process can become unbalanced, leading to increased rates of erosion as the sediment that would normally support the wetlands and beaches is removed from the system. This disruption not only accelerates erosion but also affects the health of aquatic habitats and the resilience of coastal areas to storms and rising sea levels.

Other activities, such as sand mining, also contribute to coastal erosion but to a lesser degree compared to the large-scale impact that dredging and channelization have on sediment dynamics. Fishing, while impactful in terms of ecosystem health, does not directly cause erosion in the same way. The building of sea walls can protect certain areas from erosion temporarily but can also exacerbate erosion in adjacent areas by interrupting natural processes. Hence, dredging and channelization emerge as the most significant human activities linked to coastal erosion in Louisiana.