Scientists: Gulf dead zone will decrease to average level

By Jacob Batte – Daily Comet
June 9, 2016

Scientists project the Gulf of Mexico dead zone along Louisiana’s coast that has dangerously low oxygen will decrease but still be about the size of Connecticut.

Scientists from Louisiana Universities Marine Consortium deploy a water sensor called a CTD sonde rosette to collect water samples to test for oxygen levels during the 2015 R/V Pelican’s shelf wide hypoxia cruise. Image courtesy of LUMCON

That area, also known as a hypoxic zone, forms off the coast each summer from excess fertilizer from Midwest farms and cattle pastures that washes into the Mississippi River and eventually makes its way into the Gulf.

The nitrogen and phosphorous fertilizer, coupled with the warm summer sun, trigger an explosion of algae growth that sinks and decomposes, consuming most of the life-giving oxygen in the water.

Oxygen-starved waters create an inhospitable area that forces organisms, especially bottom-feeders such as crabs and shrimp, to flee or die.

“Dead zones are a real threat to Gulf fisheries and the communities that rely on them,” said Russell Callender, assistant administrator for the National Ocean Service with the National Oceanic and Atmospheric Administration. “We’ll continue to work with our partners to advance the science to reduce that threat. One way we’re doing that is by using new tools and resources, like better predictive models, to provide better information to communities and businesses.”

This year’s area of low- to no-oxygen in the Gulf covers some 5,898 square miles, about average for the last five years, and smaller than last year’s 6,400 square miles. Projections from the National Oceanic and Atmospheric Administration’s Gulf of Mexico hypoxia forecast ranged from 5,204 to 6,823 square miles.