The Gulf of Mexico’s runoff-based “Dead Zone” Might Double


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The oxygen-poor “dead zone” in the Gulf of Mexico may be the biggest on record this year, nearly doubling in size to cover an area of ocean as large as Vermont, scientists at Louisiana State University estimate.

The dead zone develops when nitrogen-rich runoff from the Midwestern farm belt pours into rivers and out into the Gulf. That runoff is loaded with fertilizer, as well as nutrients from animal and human waste, and it fuels the growth of algae that die, sink, and decompose, depleting oxygen levels offshore. That drives away marine life in the zone — or kills species that can’t escape.

This year, LSU and its partners in the Louisiana Universities Marine Consortium estimate the zone will cover more than 10,000 square miles (26,000 square kilometers) off the shores of Louisiana and Texas. High water in the Mississippi River and higher-than-average nitrogen concentrations in the waterway this spring are driving the estimate upward, said Nancy Rabalais, a professor of marine ecosystems at LSU…

Efforts to tackle the roots of the zone have had little effect so far, Rabalais said. Some farms are adopting practices that reduce the amount of fertilizers and tilling needed to grow crops, “but the percentage of the area in the watershed is quite small.”

“There’s a federal-state task force to come up with recommendations state-by-state to reduce nutrients,” she said. “If you read the details of the forecast and the changes in flows over time, you can see there hasn’t been much of a change. Which means the few really concerted efforts to reduce nutrients have been overwhelmed by the usual way of big agribusiness in the watershed.”

Small farmers – like my kin in Canada – can’t afford to waste money on over-fertilizing. Often, they’re closer to environmental concerns, anyway. The bigger the operation, the more folks think like careless beancounters. They think they save more dollar$ by eliminating human beings than crap supplements.

3 thoughts on “The Gulf of Mexico’s runoff-based “Dead Zone” Might Double

  1. que Bottle says:

    Super informative and easy-to-read format. A few of my professors in college conduct research on the Wax Lake and Everglades, so this really hits close to home. The nitrogen-rich waters, anoxia, and algal blooms are so concerning. It’s hard to not be worried and yet still continue on with our regular days!

  2. Cassandra says:

    “Eutrophication will increase during the 21st century as a result of precipitation changes” (American Association for the Advancement of Science 7/27/17) An intensifying water cycle will likely cause dramatic increases – nearing 20% by 2100 – in the amount of nitrogen runoff in the U.S., according to a new study. Abstract: “Eutrophication, or excessive nutrient enrichment, threatens water resources across the globe. We show that climate change–induced precipitation changes alone will substantially increase (19 ± 14%) riverine total nitrogen loading within the continental United States by the end of the century for the “business-as-usual” scenario. The impacts, driven by projected increases in both total and extreme precipitation, will be especially strong for the Northeast and the corn belt of the United States. Offsetting this increase would require a 33 ± 24% reduction in nitrogen inputs, representing a massive management challenge. Globally, changes in precipitation are especially likely to also exacerbate eutrophication in India, China, and Southeast Asia. It is therefore imperative that water quality management strategies account for the impact of projected future changes in precipitation on nitrogen loading.”

  3. Jacques says:

    8/2/17: “Sea life is suffocating in a “dead zone” in the Gulf of Mexico that’s the size of New Jersey—the largest dead zone ever measured on Earth.” https://motherboard.vice.com/en_us/article/8xn4y4/sea-life-is-suffocating-in-a-dead-zone-the-size-of-new-jersey
    “According to new research funded by NOAA, and led by the Louisiana Universities Marine Consortium (LUMC), 8,776 square miles of water in the northern Gulf of Mexico is in a state of hypoxia. This means that the water has so little oxygen that sea life becomes smaller, less fertile, or is forced to migrate because there’s not enough oxygen for respiration—the equivalent of breathing.
    While the Gulf of Mexico dead zone appears naturally on a seasonal basis, it’s never been this bad before.”

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