The Gulf of Mexico’s Dead Zone Just Keeps Growing

You can’t see it from the surface, but there’s a dead zone — a region where oxygen levels are too low to support life — in the Gulf of Mexico, and it’s growing. While the size of the dead zone fluctuates throughout the year, NOAA uses forecasting methods to estimate its size during the summer peak. And this year, the news is not good.

The region is the largest ever recorded since scientists began tracking the phenomenon in 1985, spanning an area of ocean about the size of New Jersey.

Eutrophication, also known as nutrient pollution, is largely to blame for the dead zone. As it turns out, too much of a good thing is a very real issue. When large quantities of nutrients flood the ocean in the form of runoff from farms and other sites, they cause an algae bloom that chokes out oxygen, making it impossible for fish and other animals to thrive.

And when fish are displaced, it can create a ripple effect, leading to smaller shrimp and other valuable commercial species, along with an overall drop in reproduction.

Fish species move further and further away from shore, making longer travel necessary to reach them. For communities counting on the ocean to make a living, this can be devastating — and it’s not good for biodiversity either. The issue is compounded by the Gulf’s history of oil spills, which doesn’t improve the outlook for marine health.

The Mississippi River creates a perfect storm, because it drains some 40 percent of the United States, including many regions with high levels of agricultural activity. In normal conditions, runoff from land isn’t significant enough to cause massive algal blooms, but this is a man-made problem: As long as humans introduce fertilizer to watersheds, they will flood the ocean with an excess of nutrients.

When you think “agriculture,” you might visualize fertilizer runoff from crops, but a bigger culprit may be the meat industry. In addition to using fertilizer on feedlot crops, the animal agriculture also dumps large quantities of manure, all of which ends up in waterways. This year, heavier rainfall in the Midwest exacerbated the problem, contributing to the unprecedented dead zone.

The size of the dead zone indicates an impact on upstream waterways too, so it’s to the benefit of everyone to reduce nutrient pollution. Researchers find that excess nutrients, like nitrates, in streams and rivers can affect human and animal populations, including presenting some health risks.

But thankfully, there are ways to address the problem. Improvements and shifts in farming practices can make a big difference. Cover crops could reduce erosion and runoff by growing quickly to cover vulnerable land. Changing fertilizer application practices and schedules, as well as controlling animal waste, could also minimize runoff. However, these measures are all voluntary — and they’re clearly insufficient.

It can be challenging to imagine how farming practices in Nebraska could affect fisheries in Louisiana, so education and awareness campaigns may fall short. Agency rulemaking and legislation may be required to force agriculture companies — especially the massive ones likely responsible for the bulk of the problem — to adhere to tight new pollution standards.

Of note: Trump’s budget cuts include a slash in funding to the EPA program that focuses on reducing nutrient runoff.

Photo credit: NOAA Ocean Explorer


Marie W
Marie W3 months ago

Thank you.

Melania P
Melania Padilla7 months ago

We need clean energy, as soon as possible!

David C
David C8 months ago

not good, thanks

Glennis W
Glennis W8 months ago

Part of climate change frightening Thank you for caring and sharing

Glennis W
Glennis W8 months ago

Very informative amazing Thank you for caring and sharing

Glennis W
Glennis W8 months ago

Very interesting article Thank you for caring and sharing

Mark Donner
Mark Donner8 months ago

Get rid of Trump.. he's worse than a terrorist. Trump and his circle of evil are planet destroyers.

Margie F8 months ago


M. M
M. M8 months ago

This is no good news... :-/ And people keep it ignoring it.. until one day, they can't anymore... We should prevent and not react...

Carl R
Carl R8 months ago