Low oxygen 'dead zone' in Gulf of Mexico is largest ever recorded

  • 7 years ago
GULF OF MEXICO — Low oxygen areas appear yearly off the coast of Louisiana, but 2017's "dead zone" is reportedly the largest ever recorded since 1985.

According to the National Oceanic and Atmospheric Administration, this year's dead zone in the Gulf of Mexico measures 8,776 square miles, which is roughly the size of New Jersey.

The 2002 dead zone covered nearly 8,500 square miles, but the past five years have seen the area cover no more than an area of 6,000 square miles.

Dead zones are caused by nitrogen and phosphorous, which are used as crop nutrients by farmers and washed into waterways by rain.

Unusually heavy rains in the midwest are believed to have washed away more nutrients from U.S. farmlands than usual, sending them downstream via the Mississippi River.

Nitrogen and phosphorous stimulate massive algal growth in the Gulf that eventually sinks to the bottom and decomposes.

This decomposition process uses up the oxygen in the water, which renders the area uninhabitable for marine creatures.

Dead zones are usually temporary, dissipating during fall and winter. But the effects of low-oxygen or hypoxic zones on certain species can be permanent, with studies showing it affects fish reproduction and stunts shrimp growth.

Setting a federal limit on the use of crop nutrients may be one possible solution, but could prove challenging since it will need to be implemented in more than 25 states, reports NBC.

Recommended