The "dead zone" of the Gulf of Mexico | Nancy Rabalais

114,162 views ・ 2018-05-10

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Good evening, welcome to New Orleans.
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I don't know if you knew this,
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but you are sitting within 15 minutes of one of the largest rivers in the world:
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the Mississippi river.
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Old Man River, Big Muddy.
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And it goes as far north as the state of Minnesota,
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as far east as the state of New York,
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as far west as Montana.
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And 100 miles from here, river miles,
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it empties its fresh water and sediments into the Gulf of Mexico.
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That's the end of Geography 101.
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(Laughter)
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Now we're going to go to what is in that water.
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Besides the sediment, there are dissolved molecules, nitrogen and phosphorus.
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And those, through a biological process,
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lead to the formation of areas called dead zones.
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Now, dead zone is a quite ominous word
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if you're a fish or a crab.
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(Laughter)
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Even a little worm in the sediments.
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Which means that there's not enough oxygen
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for those animals to survive.
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So, how does this happen?
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The nitrogen and the phosphorus
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stimulate the growth of microscopic plants called phytoplankton.
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And small animals called zooplankton eat the phytoplankton,
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small fish eat the zooplankton, large fish eat the small fish
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and it goes on up into the food web.
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The problem is that there's just too much nitrogen and phosphorus right now,
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too much phytoplankton falling to the bottom
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and decomposed by bacteria that use up the oxygen.
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That's the biology.
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Now, you can't see it from the surface of the water,
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you can't see it in satellite images,
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so how do we know it's there?
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Well, a trawler can tell you,
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when she puts her net over the side and drags for 20 minutes
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and comes up empty,
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that she knows she's in the dead zone.
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And she has to go somewhere else.
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But where else do you go if this area is 8,000 square miles big?
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About the size of the state of New Jersey.
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Well, you either make a decision to go further,
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without much economic return,
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or go back to the dock.
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As a scientist, I have access to high-tech equipment
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that we can put over the side of the research vessel,
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and it measures oxygen and many more things.
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We start at the Mississippi River,
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we crisscross the Gulf of Mexico all the way to Texas,
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and even I sneak into Texas every now and then and test their waters.
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And you can tell by the bottom oxygen --
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you can draw a map of everything that's less than two,
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which is the magic number for when the fish start to leave the area.
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I also dive in this dead zone.
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We have oxygen meters that we have to deploy offshore
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that tell us continuous measurements of low oxygen or high oxygen.
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And when you get into the water, there's a lot of fish.
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Tons of fish, all kinds of fish,
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including my buddy here, the barracuda that I saw one day.
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Everybody else swam this way and I went this way with my camera.
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(Laughter)
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And then, down at 30 feet you start to see fewer fish.
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And then you get to the bottom.
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And you don't see any fish.
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There's no life on the platform, there's no life swimming around.
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And you know you're in the dead zone.
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So, what's the connection between the middle of the United States
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and the Gulf of Mexico?
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Well, most of the watershed is farmland.
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And in particular, corn-soybean rotation.
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The nitrogen that is put in fertilizers and the phosphorus goes on the land
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and drains off into the Mississippi River
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and ends up in the Gulf of Mexico.
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There's three times more nitrogen in the water
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in the Mississippi now,
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than there was in the 1950s.
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Three times.
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And phosphorus has doubled.
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And what that means is more phytoplankton and more sinking sails and lower oxygen.
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This is not a natural feature of the Gulf; it's been caused by human activities.
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The landscape is not what it used to be.
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It used to be prairies and forests and prairie potholes
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and duck areas and all kinds of stuff.
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But not anymore -- it's row crops.
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And there are ways that we can address this type of agriculture
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by using less fertilizer, maybe precision fertilizing.
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And trying some sustainable agriculture
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such as perennial wheatgrass, which has much longer roots
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than the six inches of a corn plant,
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that can keep the nitrogen on the soil and keep the soil from running off.
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And how do we convince our neighbors to the north,
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maybe 1,000 miles away or more,
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that their activities are causing problems with water quality in the Gulf of Mexico?
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First of all, we can take them to their own backyard.
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If you want to go swimming in Wisconsin in the summer
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in your favorite watering hole,
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you might find something like this
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which looks like spilled green paint and smells like it,
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growing on the surface of the water.
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This is a toxic blue-green algal bloom
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and it is not good for you.
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Similarly, in Lake Erie, couple of summers ago
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there was hundreds of miles of this blue-green algae
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and the city of Toledo, Ohio, couldn't use it for their drinking water
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for several days on end.
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And if you watch the news,
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you know that lots of communities are having trouble with drinking water.
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I'm a scientist.
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I don't know if you could tell that.
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(Laughter)
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And I do solid science, I publish my results,
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my colleagues read them, I get citations of my work.
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But I truly believe that, as a scientist,
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using mostly federal funds to do the research,
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I owe it to the public,
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to agency heads and congressional people
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to share my knowledge with them
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so they can use it, hopefully to make better decisions
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about our environmental policy.
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(Applause)
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Thank you.
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(Applause)
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One of the ways that I was able to do this is I brought in the media.
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And Joby Warrick from the "Washington Post"
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put this picture in an article
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on the front page, Sunday morning, two inches above the fold.
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That's a big deal.
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And Senator John Breaux, from Louisiana,
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said, "Oh my gosh, that's what they think the Gulf of Mexico looks like?"
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And I said, "Well, you know, there's the proof."
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And we've go to do something about it.
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At the same time, Senator Olympia Snowe from Maine
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was having trouble with harmful algal blooms in the Gulf of Maine.
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They joined forces -- it was bipartisan --
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(Laughter)
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(Applause)
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And invited me to give congressional testimony,
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and I said, "Oh, all I've done is chase crabs around south Texas,
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I don't know how to do that."
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(Laughter)
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But I did it.
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(Cheers)
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And eventually, the bill passed.
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And it was called -- yeah, yay!
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It was called The Harmful Algal Bloom
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and Hypoxia Research and Control Act of 1998.
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(Laughter)
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(Applause)
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Thank you.
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Which is why we call it the Snowe-Breaux Bill.
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(Laughter)
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The other thing is that we had a conference in 2001
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that was put on by the National Academy of Sciences
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that looked at fertilizers, nitrogen and poor water quality.
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Our plenary speaker was the former governor
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of the state of New Jersey.
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And she ...
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There was no thinking she wasn't serious when she peered at the audience,
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and I thought, "Surely she's looking at me."
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"You know, I'm really tired of this thing being called New Jersey.
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Pick another state, any state, I just don't want to hear it anymore."
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But she was able to move the action plan
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across President George H.W. Bush's desk
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so that we had environmental goals
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and that we were working to solve them.
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The Midwest does not feed the world.
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It feeds a lot of chickens, hogs, cattle
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and it generates ethanol
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to put into our gasoline,
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which is regulated by federal policy.
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We can do better than this.
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We need to make decisions
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that make us less consumptive
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and reduce our reliance on nitrogen.
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It's like a carbon footprint.
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But you can reduce your nitrogen footprint.
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I do it by not eating much meat --
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I still like a little every now and then --
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not using corn oil,
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driving a car that I can put nonethanol gas in
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and get better gas mileage.
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Just things like that that can make a difference.
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So I'm challenging, not just you,
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but I challenge a lot of people, especially in the Midwest --
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think about how you're treating your land and how you can make a difference.
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So my steps are very small steps.
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To change the type of agriculture in the US
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is going to be many big steps.
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And it's going to take political and social will for that to happen.
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But we can do it.
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I strongly believe we can translate the science,
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bridge it to policy and make a difference in our environment.
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We all want a clean environment.
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And we can work together to do this
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so that we no longer have these dead zones in the Gulf of Mexico.
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Thank you.
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(Applause)
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