Dead zone’s large size blamed on this year’s rainy spring
A large hypoxic zone (also known as a dead zone) the size of the land mass of Massachusetts is expected to develop in the Gulf of Mexico this summer, according to a recent NOAA report. A hypoxic zone, also known as a dead zone, is an area containing low levels of oxygen that can kill marine life. Covering an impressive 7,829 square miles, the 2019 dead zone will fall just short 2017’s record-size hypoxic zone that measured 8,776 square miles. The gulf’s hypoxic zone is an annual occurrence, and is considered one of the world’s largest. The five-year average, according to the report, is 5,770 square miles.
Nutrient pollution due to human activities is noted as the primary cause of the Gulf of Mexico’s dead zone. This year’s heavy spring rains in the Mississippi River’s agriculture-rich watershed washed larger-than-normal amounts of nitrogen and phosphorus into the gulf, acting as fertilizer to fuel excess algae growth. The overgrowth of algae robs the water of vital oxygen, killing large numbers of fish and marine life every year.
To learn more about hypoxic zones, algal blooms and nutrient pollution, read our article “Algal Blooms: Overgrowths of Algae or Cyanobacteria in Water”.