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TEDWomen 2017

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

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Ocean expert Nancy Rabalais tracks the ominously named "dead zone" in the Gulf of Mexico -- where there isn't enough oxygen in the water to support life. The Gulf has the second largest dead zone in the world; on top of killing fish and crustaceans, it's also killing fisheries in these waters. Rabalais tells us about what's causing it -- and how we can reverse its harmful effects and restore one of America's natural treasures.

- Marine scientist, educator
Nancy Rabalais has studied coastal marine ecosystems for more than 40 years now and loves to share that knowledge. Full bio

Good evening, welcome to New Orleans.
00:13
I don't know if you knew this,
00:16
but you are sitting within 15 minutes
of one of the largest rivers in the world:
00:17
the Mississippi river.
00:24
Old Man River, Big Muddy.
00:26
And it goes as far north
as the state of Minnesota,
00:29
as far east as the state of New York,
00:34
as far west as Montana.
00:38
And 100 miles from here, river miles,
00:42
it empties its fresh water and sediments
into the Gulf of Mexico.
00:45
That's the end of Geography 101.
00:51
(Laughter)
00:54
Now we're going to go
to what is in that water.
00:55
Besides the sediment, there are dissolved
molecules, nitrogen and phosphorus.
00:59
And those, through a biological process,
01:06
lead to the formation
of areas called dead zones.
01:10
Now, dead zone is a quite ominous word
01:16
if you're a fish or a crab.
01:21
(Laughter)
01:23
Even a little worm in the sediments.
01:25
Which means that there's not enough oxygen
01:28
for those animals to survive.
01:31
So, how does this happen?
01:35
The nitrogen and the phosphorus
01:37
stimulate the growth of microscopic plants
called phytoplankton.
01:39
And small animals called zooplankton
eat the phytoplankton,
01:45
small fish eat the zooplankton,
large fish eat the small fish
01:51
and it goes on up into the food web.
01:55
The problem is that there's just too much
nitrogen and phosphorus right now,
01:58
too much phytoplankton
falling to the bottom
02:02
and decomposed by bacteria
that use up the oxygen.
02:05
That's the biology.
02:11
Now, you can't see it
from the surface of the water,
02:13
you can't see it in satellite images,
02:17
so how do we know it's there?
02:19
Well, a trawler can tell you,
02:21
when she puts her net over the side
and drags for 20 minutes
02:24
and comes up empty,
02:29
that she knows she's in the dead zone.
02:30
And she has to go somewhere else.
02:33
But where else do you go
if this area is 8,000 square miles big?
02:35
About the size of the state of New Jersey.
02:41
Well, you either make
a decision to go further,
02:44
without much economic return,
02:49
or go back to the dock.
02:51
As a scientist, I have access
to high-tech equipment
02:54
that we can put over the side
of the research vessel,
02:58
and it measures oxygen
and many more things.
03:01
We start at the Mississippi River,
03:03
we crisscross the Gulf of Mexico
all the way to Texas,
03:06
and even I sneak into Texas
every now and then and test their waters.
03:10
And you can tell by the bottom oxygen --
03:16
you can draw a map
of everything that's less than two,
03:20
which is the magic number
for when the fish start to leave the area.
03:23
I also dive in this dead zone.
03:29
We have oxygen meters
that we have to deploy offshore
03:33
that tell us continuous measurements
of low oxygen or high oxygen.
03:37
And when you get into the water,
there's a lot of fish.
03:42
Tons of fish, all kinds of fish,
03:45
including my buddy here,
the barracuda that I saw one day.
03:47
Everybody else swam this way
and I went this way with my camera.
03:52
(Laughter)
03:56
And then, down at 30 feet
you start to see fewer fish.
03:57
And then you get to the bottom.
04:02
And you don't see any fish.
04:04
There's no life on the platform,
there's no life swimming around.
04:06
And you know you're in the dead zone.
04:11
So, what's the connection
between the middle of the United States
04:15
and the Gulf of Mexico?
04:19
Well, most of the watershed is farmland.
04:21
And in particular, corn-soybean rotation.
04:25
The nitrogen that is put in fertilizers
and the phosphorus goes on the land
04:30
and drains off into the Mississippi River
04:36
and ends up in the Gulf of Mexico.
04:39
There's three times more
nitrogen in the water
04:42
in the Mississippi now,
04:47
than there was in the 1950s.
04:49
Three times.
04:51
And phosphorus has doubled.
04:52
And what that means is more phytoplankton
and more sinking sails and lower oxygen.
04:54
This is not a natural feature of the Gulf;
it's been caused by human activities.
05:00
The landscape is not what it used to be.
05:06
It used to be prairies and forests
and prairie potholes
05:08
and duck areas and all kinds of stuff.
05:13
But not anymore -- it's row crops.
05:17
And there are ways that we can address
this type of agriculture
05:20
by using less fertilizer,
maybe precision fertilizing.
05:25
And trying some sustainable agriculture
05:31
such as perennial wheatgrass,
which has much longer roots
05:34
than the six inches of a corn plant,
05:39
that can keep the nitrogen on the soil
and keep the soil from running off.
05:41
And how do we convince
our neighbors to the north,
05:47
maybe 1,000 miles away or more,
05:51
that their activities are causing problems
with water quality in the Gulf of Mexico?
05:54
First of all, we can take them
to their own backyard.
06:01
If you want to go swimming
in Wisconsin in the summer
06:04
in your favorite watering hole,
06:08
you might find something like this
06:11
which looks like spilled green paint
and smells like it,
06:14
growing on the surface of the water.
06:18
This is a toxic blue-green algal bloom
06:21
and it is not good for you.
06:25
Similarly, in Lake Erie,
couple of summers ago
06:29
there was hundreds of miles
of this blue-green algae
06:33
and the city of Toledo, Ohio,
couldn't use it for their drinking water
06:37
for several days on end.
06:41
And if you watch the news,
06:43
you know that lots of communities
are having trouble with drinking water.
06:45
I'm a scientist.
06:53
I don't know if you could tell that.
06:55
(Laughter)
06:57
And I do solid science,
I publish my results,
07:01
my colleagues read them,
I get citations of my work.
07:05
But I truly believe that, as a scientist,
07:10
using mostly federal funds
to do the research,
07:15
I owe it to the public,
07:20
to agency heads and congressional people
07:23
to share my knowledge with them
07:27
so they can use it,
hopefully to make better decisions
07:29
about our environmental policy.
07:33
(Applause)
07:36
Thank you.
07:38
(Applause)
07:39
One of the ways that I was able to do this
is I brought in the media.
07:43
And Joby Warrick
from the "Washington Post"
07:47
put this picture in an article
07:52
on the front page, Sunday morning,
two inches above the fold.
07:55
That's a big deal.
08:00
And Senator John Breaux, from Louisiana,
08:02
said, "Oh my gosh, that's what they think
the Gulf of Mexico looks like?"
08:05
And I said, "Well, you know,
there's the proof."
08:09
And we've go to do something about it.
08:12
At the same time,
Senator Olympia Snowe from Maine
08:15
was having trouble with harmful
algal blooms in the Gulf of Maine.
08:20
They joined forces -- it was bipartisan --
08:24
(Laughter)
08:27
(Applause)
08:29
And invited me to give
congressional testimony,
08:31
and I said, "Oh, all I've done
is chase crabs around south Texas,
08:34
I don't know how to do that."
08:37
(Laughter)
08:39
But I did it.
08:40
(Cheers)
08:41
And eventually, the bill passed.
08:43
And it was called -- yeah, yay!
08:44
It was called The Harmful Algal Bloom
08:47
and Hypoxia Research
and Control Act of 1998.
08:50
(Laughter)
08:55
(Applause)
08:56
Thank you.
09:00
Which is why we call it
the Snowe-Breaux Bill.
09:01
(Laughter)
09:03
The other thing is
that we had a conference in 2001
09:06
that was put on by
the National Academy of Sciences
09:13
that looked at fertilizers,
nitrogen and poor water quality.
09:16
Our plenary speaker
was the former governor
09:21
of the state of New Jersey.
09:25
And she ...
09:28
There was no thinking she wasn't serious
when she peered at the audience,
09:30
and I thought,
"Surely she's looking at me."
09:35
"You know, I'm really tired
of this thing being called New Jersey.
09:38
Pick another state, any state,
I just don't want to hear it anymore."
09:42
But she was able to move the action plan
09:46
across President George H.W. Bush's desk
09:50
so that we had environmental goals
09:56
and that we were working to solve them.
09:59
The Midwest does not feed the world.
10:04
It feeds a lot of chickens, hogs, cattle
10:07
and it generates ethanol
10:13
to put into our gasoline,
10:15
which is regulated by federal policy.
10:18
We can do better than this.
10:22
We need to make decisions
10:25
that make us less consumptive
10:28
and reduce our reliance on nitrogen.
10:34
It's like a carbon footprint.
10:39
But you can reduce
your nitrogen footprint.
10:42
I do it by not eating much meat --
10:45
I still like a little
every now and then --
10:50
not using corn oil,
10:52
driving a car that I can put
nonethanol gas in
10:55
and get better gas mileage.
10:59
Just things like that
that can make a difference.
11:02
So I'm challenging, not just you,
11:05
but I challenge a lot of people,
especially in the Midwest --
11:08
think about how you're treating your land
and how you can make a difference.
11:12
So my steps are very small steps.
11:18
To change the type
of agriculture in the US
11:22
is going to be many big steps.
11:26
And it's going to take political
and social will for that to happen.
11:28
But we can do it.
11:33
I strongly believe
we can translate the science,
11:35
bridge it to policy and make
a difference in our environment.
11:39
We all want a clean environment.
11:44
And we can work together to do this
11:47
so that we no longer have
these dead zones in the Gulf of Mexico.
11:49
Thank you.
11:53
(Applause)
11:55

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About the speaker:

Nancy Rabalais - Marine scientist, educator
Nancy Rabalais has studied coastal marine ecosystems for more than 40 years now and loves to share that knowledge.

Why you should listen

Nancy Rabalais has worked in Louisiana ever since she got her PhD in 1983, studying aspects of marine ecology relevant to environmental health. As she writes: "I work on areas called 'dead zones' that are coastal waters lacking in oxygen in which animals such as fish, shrimp and crabs cannot live. I am also, since 2011, studying the long-term effects of the Deepwater Horizon oil spill on coastal waters and Louisiana wetlands.

"I fell in love with biology in the 8th grade and then marine biology in college. My education was not quite the typical 'academic' training. I worked my way through college, beginning at a two-year college, a regional university for my BS and MS, then worked at the University of Texas Marine Science Institute in Port Aransas, Texas, for three years. My desire for further education sent me back to work on my PhD at The University of Texas at Austin. My first job as a PhD was at the Louisiana Universities Marine Consortium, starting in 1983. I am now a professor and Shell Endowed Chair of Oceanography and Coastal Sciences at Louisiana State University."

More profile about the speaker
Nancy Rabalais | Speaker | TED.com