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  • Good evening, welcome to New Orleans.

  • I don't know if you knew this,

  • but you are sitting within 15 minutes of one of the largest rivers in the world:

  • the Mississippi river.

  • Old Man River, Big Muddy.

  • And it goes as far north as the state of Minnesota,

  • as far east as the state of New York,

  • as far west as Montana.

  • And 100 miles from here, river miles,

  • it empties its fresh water and sediments into the Gulf of Mexico.

  • That's the end of Geography 101.

  • (Laughter)

  • Now we're going to go to what is in that water.

  • Besides the sediment, there are dissolved molecules, nitrogen and phosphorus.

  • And those, through a biological process,

  • lead to the formation of areas called dead zones.

  • Now, dead zone is a quite ominous word

  • if you're a fish or a crab.

  • (Laughter)

  • Even a little worm in the sediments.

  • Which means that there's not enough oxygen

  • for those animals to survive.

  • So, how does this happen?

  • The nitrogen and the phosphorus

  • stimulate the growth of microscopic plants called phytoplankton.

  • And small animals called zooplankton eat the phytoplankton,

  • small fish eat the zooplankton, large fish eat the small fish

  • and it goes on up into the food web.

  • The problem is that there's just too much nitrogen and phosphorus right now,

  • too much phytoplankton falling to the bottom

  • and decomposed by bacteria that use up the oxygen.

  • That's the biology.

  • Now, you can't see it from the surface of the water,

  • you can't see it in satellite images,

  • so how do we know it's there?

  • Well, a trawler can tell you,

  • when she puts her net over the side and drags for 20 minutes

  • and comes up empty,

  • that she knows she's in the dead zone.

  • And she has to go somewhere else.

  • But where else do you go if this area is 8,000 square miles big?

  • About the size of the state of New Jersey.

  • Well, you either make a decision to go further,

  • without much economic return,

  • or go back to the dock.

  • As a scientist, I have access to high-tech equipment

  • that we can put over the side of the research vessel,

  • and it measures oxygen and many more things.

  • We start at the Mississippi River,

  • we crisscross the Gulf of Mexico all the way to Texas,

  • and even I sneak into Texas every now and then and test their waters.

  • And you can tell by the bottom oxygen --

  • you can draw a map of everything that's less than two,

  • which is the magic number for when the fish start to leave the area.

  • I also dive in this dead zone.

  • We have oxygen meters that we have to deploy offshore

  • that tell us continuous measurements of low oxygen or high oxygen.

  • And when you get into the water, there's a lot of fish.

  • Tons of fish, all kinds of fish,

  • including my buddy here, the barracuda that I saw one day.

  • Everybody else swam this way and I went this way with my camera.

  • (Laughter)

  • And then, down at 30 feet you start to see fewer fish.

  • And then you get to the bottom.

  • And you don't see any fish.

  • There's no life on the platform, there's no life swimming around.

  • And you know you're in the dead zone.

  • So, what's the connection between the middle of the United States

  • and the Gulf of Mexico?

  • Well, most of the watershed is farmland.

  • And in particular, corn-soybean rotation.

  • The nitrogen that is put in fertilizers and the phosphorus goes on the land

  • and drains off into the Mississippi River

  • and ends up in the Gulf of Mexico.

  • There's three times more nitrogen in the water

  • in the Mississippi now,

  • than there was in the 1950s.

  • Three times.

  • And phosphorus has doubled.

  • And what that means is more phytoplankton and more sinking sails and lower oxygen.

  • This is not a natural feature of the Gulf; it's been caused by human activities.

  • The landscape is not what it used to be.

  • It used to be prairies and forests and prairie potholes

  • and duck areas and all kinds of stuff.

  • But not anymore -- it's row crops.

  • And there are ways that we can address this type of agriculture

  • by using less fertilizer, maybe precision fertilizing.

  • And trying some sustainable agriculture

  • such as perennial wheatgrass, which has much longer roots

  • than the six inches of a corn plant,

  • that can keep the nitrogen on the soil and keep the soil from running off.

  • And how do we convince our neighbors to the north,

  • maybe 1,000 miles away or more,

  • that their activities are causing problems with water quality in the Gulf of Mexico?

  • First of all, we can take them to their own backyard.

  • If you want to go swimming in Wisconsin in the summer

  • in your favorite watering hole,

  • you might find something like this

  • which looks like spilled green paint and smells like it,

  • growing on the surface of the water.

  • This is a toxic blue-green algal bloom

  • and it is not good for you.

  • Similarly, in Lake Erie, couple of summers ago

  • there was hundreds of miles of this blue-green algae

  • and the city of Toledo, Ohio, couldn't use it for their drinking water

  • for several days on end.

  • And if you watch the news,

  • you know that lots of communities are having trouble with drinking water.

  • I'm a scientist.

  • I don't know if you could tell that.

  • (Laughter)

  • And I do solid science, I publish my results,

  • my colleagues read them, I get citations of my work.

  • But I truly believe that, as a scientist,

  • using mostly federal funds to do the research,

  • I owe it to the public,

  • to agency heads and congressional people

  • to share my knowledge with them

  • so they can use it, hopefully to make better decisions

  • about our environmental policy.

  • (Applause)

  • Thank you.

  • (Applause)

  • One of the ways that I was able to do this is I brought in the media.

  • And Joby Warrick from the "Washington Post"

  • put this picture in an article

  • on the front page, Sunday morning, two inches above the fold.

  • That's a big deal.

  • And Senator John Breaux, from Louisiana,

  • said, "Oh my gosh, that's what they think the Gulf of Mexico looks like?"

  • And I said, "Well, you know, there's the proof."

  • And we've go to do something about it.

  • At the same time, Senator Olympia Snowe from Maine

  • was having trouble with harmful algal blooms in the Gulf of Maine.

  • They joined forces -- it was bipartisan --

  • (Laughter)

  • (Applause)

  • And invited me to give congressional testimony,

  • and I said, "Oh, all I've done is chase crabs around south Texas,

  • I don't know how to do that."

  • (Laughter)

  • But I did it.

  • (Cheers)

  • And eventually, the bill passed.

  • And it was called -- yeah, yay!

  • It was called The Harmful Algal Bloom

  • and Hypoxia Research and Control Act of 1998.

  • (Laughter)

  • (Applause)

  • Thank you.

  • Which is why we call it the Snowe-Breaux Bill.

  • (Laughter)

  • The other thing is that we had a conference in 2001

  • that was put on by the National Academy of Sciences

  • that looked at fertilizers, nitrogen and poor water quality.

  • Our plenary speaker was the former governor

  • of the state of New Jersey.

  • And she ...

  • There was no thinking she wasn't serious when she peered at the audience,

  • and I thought, "Surely she's looking at me."

  • "You know, I'm really tired of this thing being called New Jersey.

  • Pick another state, any state, I just don't want to hear it anymore."

  • But she was able to move the action plan

  • across President George H.W. Bush's desk

  • so that we had environmental goals

  • and that we were working to solve them.

  • The Midwest does not feed the world.

  • It feeds a lot of chickens, hogs, cattle

  • and it generates ethanol

  • to put into our gasoline,

  • which is regulated by federal policy.

  • We can do better than this.

  • We need to make decisions

  • that make us less consumptive

  • and reduce our reliance on nitrogen.

  • It's like a carbon footprint.

  • But you can reduce your nitrogen footprint.

  • I do it by not eating much meat --

  • I still like a little every now and then --

  • not using corn oil,

  • driving a car that I can put nonethanol gas in

  • and get better gas mileage.

  • Just things like that that can make a difference.

  • So I'm challenging, not just you,

  • but I challenge a lot of people, especially in the Midwest --

  • think about how you're treating your land and how you can make a difference.

  • So my steps are very small steps.

  • To change the type of agriculture in the US

  • is going to be many big steps.

  • And it's going to take political and social will for that to happen.

  • But we can do it.

  • I strongly believe we can translate the science,

  • bridge it to policy and make a difference in our environment.

  • We all want a clean environment.

  • And we can work together to do this

  • so that we no longer have these dead zones in the Gulf of Mexico.

  • Thank you.

  • (Applause)

Good evening, welcome to New Orleans.

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B1 US TED gulf nitrogen fish oxygen mexico

【TED】Nancy Rabalais: The "dead zone" of the Gulf of Mexico (The "dead zone" of the Gulf of Mexico | Nancy Rabalais)

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    Zenn posted on 2018/05/10
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