What causes the Louisiana dead zone?

The Louisiana dead zone is primarily caused by excessive nutrient pollution, particularly from fertilizers, which promote algal blooms in the Gulf of Mexico. When these blooms occur, they cover the surface of the water, preventing sunlight from reaching lower levels. Eventually, the algae die off and decompose, a process that consumes dissolved oxygen in the water. This depletion of oxygen creates hypoxic conditions, or "dead zones," where marine life cannot survive.

The significant runoff of fertilizers, which is often a result of agricultural practices in the Mississippi River basin, plays a crucial role in this ecological issue. As such, it highlights the interconnectedness of land management practices and the health of aquatic ecosystems. This understanding can guide better practices aimed at reducing nutrient runoff, ultimately helping to mitigate the effects and occurrence of dead zones.