Slightly-below average this year

The Gulf of Mexico dead zone, an area of low oxygen that harms marine life, was slightly below-average during a recent boat survey.

Although that is good news, there is some bad news too. The dead zone still covered 3,058 square miles, which is about twice the size of Rhode Island. A task force of university researchers and government scientists are working to lower the dead zone to 1,900 square miles by 2035.

The dead zone develops over the northern Gulf of Mexico just south of Louisiana each summer. It occurs when nutrient-rich water streams into the Gulf during the spring floods rolling down the Mississippi River and flushing into the Gulf of Mexico via the river’s delta.

The nutrients, rich in nitrogen and phosphorus from agriculture fertilizers, runoff from yards and treated sewage, feed algae, creating a bloom in the northern Gulf of Mexico. The algae die and sink to the bottom, where anaerobic bacteria decompose the algae, removing dissolved oxygen. This creates a hypoxic area at the bottom of the Gulf of Mexico.

Marine life in this area, lacking oxygen, either swim away from these areas or die. The low oxygen levels can also affect marine life and fish metabolism and growth. It has even been found to affect the price of gulf shrimp. Researchers have found that during high hypoxic events, shrimp sizes are usually smaller, causing prices for large-size shrimp to be higher. A higher ratio of smaller shrimp to higher shrimp can also affect fishermen’s revenue, even with the large shrimp prices.

The federal government, through grants and other financial incentives, is working with upstream states to mitigate the nutrients flowing downriver. This includes creating plans to upgrade water treatment facilities, monitor septic systems and improve drainage techniques along fields and in flood plains.