Gulf of Mexico's 'dead zone' may be largest in history
GULF OF MEXICO — The Gulf of Mexico could have a dead zone almost 8,000 square miles in size due to this year's record-breaking rainfall in the American Midwest, according to the National Oceanic and Atmospheric Administration.
Citing scientists' predictions, the NOAA says the dead zone could be one of the largest on record.
Dead zones, also referred to as hypoxic zones, have low-oxygen levels that are deadly to marine life.
These occur as nutrients present in fertilizers, such as nitrogen and phosphorus, are washed into rivers due to annual rainfall.
Nutrients present in the river water runoff then cause algae to grow in ocean water, as fresh water doesn't mix with the ocean's due to its density.
Louisiana State University ocean ecologist, Nancy Rabalais, told National Geographic that animals such as shrimp and fish will swim away from hypoxic zones when oxygen levels drop below two parts per million.
Farmers are starting to adopt practices such as making less use of fertilizers and using more cover crops to decrease nutrient runoff, as reported by National Geographic.