CURRENT EXAMPLES

One of the biggest dead zones is in the Gulf of Mexico. It covers up to 5000 square miles in the area that is the richest for shellfish populations The dead zone has caused the collapse of the shrimp and shellfish industries in that region. The dead zone was created because the Mississippi River collects roughly 10,000 pounds of fertilizer and raw sewage pollution from 31 states as it travels south. This warm, nutrient-rich freshwater does not mix well with the colder saltwater, causing phytoplankton to grow uncontrollably. The zooplankton that feeds on them also grows. When these plankton die, they sink to the bottom and bacteria metabolize the available dissolved oxygen oxygen as they decompose the detritus. The lack of oxygen creates a hypoxic zone. A Hypoxia Task Force was created to address the issue but have seen few promising results. 

In the Black Sea (one of the largest anoxic basins), hypoxic waters from cultural eutrophication have resulted in massive fish kills, with rippling effects throughout the food chain and local economies. 

The Dead Zone in the Chesapeake Bay is one of the first ones ever identified, and is caused by heavy urbanization and agriculture.

The Baltic Sea is home to seven of the world’s 10 largest marine dead zones. It is known for the fishing of cod and cultural eutrophication has several problems.