Largest dead zone ever hits the Gulf of Mexico

And climate change will only make dead zones worse.

(AP Photo/Patrick Semansky)
(AP Photo/Patrick Semansky)

Scientists have measured a dead zone the size of New Jersey in the Gulf of Mexico, making it the largest-ever dead zone recorded in the area, according to the National Oceanic and Atmospheric Association.

A dead zone occurs when nutrient pollution — largely from agricultural runoff like fertilizer and manure — makes its way into bodies of water, fueling algal growth. When the algae dies, it decomposes, creating oxygen-free zones that can no longer sustain marine life.

This year’s dead zone measures 8,776 square miles, beating out the previous record of 8,497 square miles set in 2002. For the last 32 years of monitoring, the dead zone in the Gulf has averaged 5,309 square miles.

“The results from this year reflect the nitrate flux into the Gulf, which was high,” says Nancy Rabalais, a research professor at the Louisiana Universities Marine Consortium (LUMCON), who helped measure the dead zone, told National Geographic. “It’s a matter of addressing the sources of the nitrate—where they first start—which is in a field of agricultural crops.”

Rabalais said that this year’s especially large dead zone is likely a result of heavier stream flows in the spring, which helped carry more nutrient pollution from the agricultural fields of the Midwest down to the Gulf.

But a report by the environmental group Mighty suggests that this year’s extra-large dead zone is a direct result of industrial meat production, which feeds nutrient runoff both through manure produced by the animals and fertilizer used to grow animal feed. The report looks at companies responsible for large amounts of nutrient runoff, and implicates Tyson Foods, the largest meat company in the United States, as a key culprit behind the dead zone. According to the report, Tyson has major processing facilities in every state listed by the United States Geological Survey as states from which nutrient runoff flows to the Gulf.

Another report, released last year by Environment America, found that Tyson dumps more waste into American waterways each year than companies like Exxon or Dow Chemical.

“Americans should not have to choose between producing food and having healthy clean water,” Mighty Earth campaign director Lucia von Reusner said in a statement. “Big meat companies like Tyson have left a trail of pollution across the country, and have a responsibility to their customers and the public to clean it up.”

While this year’s dead zone is record-shattering, it’s likely that these zones will only increase in size in the future, as climate change drives more intense precipitation and, in turn, more nutrient pollution. A recent study in Science found that increased precipitation from climate change would translate to a 19 percent increase in nitrogen — a nutrient found in both manure and agricultural fertilizer — in Americans rivers by the end of the century.

Under the Obama administration, the United States Department of Agriculture had begun to take steps to help farmers reduce their nutrient runoff, from encouraging farmers to use precision agriculture techniques — where fertilizer is applied more sparingly to fields, in precise locations — to investing millions in programs aimed at boosting soil health. The Obama Environmental Protection Agency also provided millions of dollars in grants to states to help target non-source pollution.

That appears to be changing under the Trump administration, however. The Trump administration’s budget zeroes out EPA grants for non-source pollution, arguing that the USDA should be the only agency tackling the program. And Trump’s Secretary of Agriculture Sonny Perdue owned an inorganic fertilizer company before entering into politics, raising questions about a potential conflict of interest in regulating fertilizer use in agriculture.