Aug 09, 2017

Dead on Arrival

Amy McIntosh

In 2013, the National Oceanic and Atmospheric Administration (NOAA) debunked the myth of the Pacific Garbage Patch, an alleged floating pile of garbage in the Pacific Ocean rumored to be larger than the state of Texas. While there certainly is a lot of trash floating in the ocean, NOAA noted that it is not concentrated in one large mass and includes a high concentration of micropollutants. For decades, however, the illusion of this floating island of garbage was enough to bring awareness to a global pollution problem.

In June 2017, NOAA released research results announcing this summer’s real threat, this time the size of New Jersey: the Gulf of Mexico’s dead zone. This low-to-no-oxygen environment cannot support marine life. Based on nutrient runoff and river discharge data from the U.S. Geological Survey, the NOAA study estimates an 8,185-sq-mile dead zone in the gulf, making it the Gulf of Mexico's third-largest since the agency began monitoring 32 years ago. The zone’s average size is 5,309 sq miles.

Although coastal fishing communities in Louisiana feel the brunt of the dead zone, the issue of hypoxia begins farther north, in the Midwestern states along the Mississippi and Atchafalaya rivers. Nutrients from fertilizer-laden agricultural runoff and untreated wastewater make their way to the rivers, stimulating the growth of algae, which eventually dies and sinks to the bottom of the river to decompose. By the time this water reaches the Gulf of Mexico, oxygen levels are depleted and marine life is generally unsustainable.

NOAA estimates that in May 2017 alone, 165,000 metric tons of nitrate—the equivalent of 2,800 train cars of fertilizer—and 22,600 metric tons of phosphorus flowed into the gulf.

This means a few things. For one, the price of seafood is likely to increase. But the data also indicate a larger responsibility for those in farming communities to be mindful of runoff. NOAA’s Runoff Risk Advisory Forecasts are designed to help farmers know when to avoid fertilizing their crops. The agency’s website offers other educational resources about nonpoint source pollution.

Maintaining compliance with runoff regulations is important, but many states do not have official permitting standards for agriculture. Just as the thought of a floating garbage island may have prompted consumers to be more mindful of their trash, the state-sized dead zone should prompt dischargers in these river basins to be mindful of their runoff. It is important to be responsible dischargers regardless of regulations to protect not only local waterways, but the health of downstream waters. 

About the author

Amy McIntosh, managing editor, [email protected]