A dead zone in the Gulf of Mexico, an area with low oxygen that is harmful to marine life, has grown in size this summer, scientists at the National Oceanic and Atmospheric Administration (NOAA) said Tuesday. Heavy rainfall in June across the Mississippi River watershed and a loss of nutrients in the water were cited as possible causes.
This year, the dead zone is over 5,000 square miles large and is equivalent to the combined size of Connecticut and Rhode Island, according to NOAA. Also known as hypoxia, the dead zone is formed mostly from the overuse of fertilizers on farming land. Nutrients such as nitrogen allow algae to flourish and consume the oxygen that’s needed to support life in the water, leading to depleted populations of fish, shrimps, crabs and other marine life. Annual measurements of the dead zone began in 1985.
“The heavy rains that came in June with additional nitrogen and even higher river discharges in July are the possible explanations for the larger size,” Nancy Rabalais, executive director of the Louisiana Universities Marine Consortium, who led the scientific cruise to examine the area, said.