Higher than average rainfalls in the Midwest U.S. and Central Plains region have led NOAA scientists to forecast an unusually large dead zone in the Gulf of Mexico this summer.
That precipitation, mixed with nutrient runoffs from cities and farms in those regions, will lead to an area of nearly 8,000 square miles near the Gulf floor that will not be inhabitable for most marine life forms.
The zone over the last five years has averaged 5,770 square miles. The record was set in 2017, when it amassed 8,776 square miles, or nearly the size of New Hampshire.
NOAA scientists use data from the U.S. Geological Society to make their forecasts. In August NOAA officials will conduct a survey to determine the actual size and compare it to the forecast.
The area, officially called a hypoxic zone, occurs every summer as algae bloom in the Gulf waters. When they die, they settle to the bottom, decompose and limit the amount of oxygen in the area. The Gulf’s zone is considered one of the largest in the world.
According to NOAA, the amount of discharge in the Mississippi and Atchafalaya rivers last month was two-thirds higher than the 38-year average from the region. As a result, 156,000 metric tons of nitrate and more than 25,000 metric tons of phosphorus were dumped into the Gulf.
“Long-term monitoring of the country's streams and rivers by the USGS has shown that while nitrogen loading into some other coastal estuaries has been decreasing, that is not the case in the Gulf of Mexico," said Don Cline, associate director for the USGS Water Resources Mission Area, in a statement.
In its analysis, Mighty Earth, a global environmental advocacy group, blamed factory farms for the water pollution that will enlarge the dead zone this year. Those farms dumped 128 million tons of manure into the Mississippi River watershed.
“With the climate crises worsening and the Trump administration working to further roll back environmental regulations on industry, it is critical that the American public understand the sources and vast amounts of pollution washing into our waterways in order to hold specific companies and policymakers responsible for curbing uncontrolled industrial runoff,” according to the Mighty Earth analysis.
Photo courtesy of NOAA
