Dead Zones, Now in More Frightening Detail!

Last July NASA released a world map that identifies hundreds of areas in the world’s oceans with dangerously low oxygen levels. These hypoxic areas – virtually uninhabitable for most marine life – are a result of eutrophication, or too many nutrients from fertilizer runoff and sewage discharges finding their way into coastal waters.

The NASA map of dead zones, as they are commonly called, is impressive in its scope and ability to make one both furious and fetal-position sad at the same time. But static, non-interactive maps, no matter how distressing, are hard to get too excited about in these glory days of online mapping.

Enter the World Resources Institute (WRI) and its interactive and exhaustively-researched map of 762 (and counting) eutrophic and hypoxic sites around the world, each identified with accompanying descriptions, photos and even videos.

Surfing through the map without a guide can be a daunting task, so I asked WRI’s Mindy Selman to tell me a little more about what trends really stand out for her.

“To me what is most striking is the pervasiveness of this problem—literally no continent is untouched (we even created water quality problems in Antarctica at McMurdo station),” she said.

As Selman explained, the doubling of nitrogen and tripling of phosphorous in the environment since 1960 – primarily from intensive agriculture – correlates with the explosive growth in the number of hypoxic and eutrophic sites. Given the continued industrialization of the world’s agricultural system, the future doesn’t look much better.

“What is really scary is that experts expect that we will double reactive nitrogen levels again in the next 50 years,” Selman explained. “The water quality implications of that are absolutely astounding.”

As scary as the continued worldwide growth of oceanic dead zones might be, the issue has resonated little with the public, a fact that inspired the creation of WRI’s interactive map.

The project’s roots date back to 2007 when WRI gathered eutrophication experts to look at not just where dissolved oxygen levels were dropping, but what the causes were, how the problem could be addressed and the greatest barriers to those solutions. It turns out that one of the primary impediments to tackling eutrophication is a lack of public awareness – even a basic understanding of what it is and the problems it can cause. In response, WRI teamed up with the Virginia Institute of Marine Science to create a eutrophication web portal, and the map itself was launched after a year of compiling data, photos, videos and individual write-ups.

Take a look at the map and you'll notice dense coverage of the United States and European Atlantic coasts thanks to readily available surveys, but in other regions data is a lot tougher to come by. “For most other countries we had to dig for information in scientific journals,” Selman said, “and it wasn’t collected all in one place.”

When I asked if there are any particular areas on the current map that are underrepresented, Selman responded, “China and India both show about 10 impaired systems each—those are certainly under-representations of the water quality problems in those countries (based on the amount of people and agriculture there). There are several other places in Southeast Asia, South America, etc. where I'd expect to see more.”

One of the map’s most powerful features is its ability to show the locations of hypoxic and eutrophic sites over time. The increase in the number of sites has been dramatic, especially over the past 30 years. But with listings dating back to 1850, how much of this increase has to do with data availability versus changing conditions?

“Certainly eutrophication is more widely recognized now,” Selman answered. “So while we might classify a site as becoming eutrophic/hypoxic in the 2000’s, maybe it was experiencing issues beforehand. However, the general trend speaks for itself—there are definitely more impaired coastal ecosystems today than 50 years ago. And …this is correlated with the significant increases in nutrients to the environment from agriculture and other human-related activities.”

Despite the massive amount of research already conducted, data availability remains a challenge. But true to its map’s interactive nature, WRI is looking for feedback from everyone – experts and concerned amateurs alike – to add to or tweak the existing list of sites.

“We are constantly adding new sites to list as we find out about them,” Selman said. “That’s one of the things we're hoping to get from this project—is a clearer picture of the problem as experts view the site and let us know what’s missing, what we might have misclassified… Hopefully we'll start filling in those gaps!”

You have your orders, ocean lovers.

Responses to "Dead Zones, Now in More Frightening Detail!"

  1. joseph kahoe

    I believe someday in the far future we will be able to meet the efforts of many dedicated groups to make earth a less toxic place to live. That day will come. Unfortunately it does not reflect todays reality on the ugly facts that we still have to rely on

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