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

110,161 views ・ 2018-05-10

TED


Please double-click on the English subtitles below to play the video.

00:13
Good evening, welcome to New Orleans.
0
13040
3176
00:16
I don't know if you knew this,
1
16240
1536
00:17
but you are sitting within 15 minutes of one of the largest rivers in the world:
2
17800
6336
00:24
the Mississippi river.
3
24160
1280
00:26
Old Man River, Big Muddy.
4
26360
2440
00:29
And it goes as far north as the state of Minnesota,
5
29560
4496
00:34
as far east as the state of New York,
6
34080
4336
00:38
as far west as Montana.
7
38440
3656
00:42
And 100 miles from here, river miles,
8
42120
3336
00:45
it empties its fresh water and sediments into the Gulf of Mexico.
9
45480
4600
00:51
That's the end of Geography 101.
10
51080
3176
00:54
(Laughter)
11
54280
1096
00:55
Now we're going to go to what is in that water.
12
55400
3936
00:59
Besides the sediment, there are dissolved molecules, nitrogen and phosphorus.
13
59360
5960
01:06
And those, through a biological process,
14
66120
3160
01:10
lead to the formation of areas called dead zones.
15
70600
5200
01:16
Now, dead zone is a quite ominous word
16
76400
4160
01:21
if you're a fish or a crab.
17
81880
2056
01:23
(Laughter)
18
83960
1536
01:25
Even a little worm in the sediments.
19
85520
2976
01:28
Which means that there's not enough oxygen
20
88520
3056
01:31
for those animals to survive.
21
91600
2640
01:35
So, how does this happen?
22
95680
1736
01:37
The nitrogen and the phosphorus
23
97440
2216
01:39
stimulate the growth of microscopic plants called phytoplankton.
24
99680
4960
01:45
And small animals called zooplankton eat the phytoplankton,
25
105760
5576
01:51
small fish eat the zooplankton, large fish eat the small fish
26
111360
3936
01:55
and it goes on up into the food web.
27
115320
2776
01:58
The problem is that there's just too much nitrogen and phosphorus right now,
28
118120
4536
02:02
too much phytoplankton falling to the bottom
29
122680
3216
02:05
and decomposed by bacteria that use up the oxygen.
30
125920
5496
02:11
That's the biology.
31
131440
1760
02:13
Now, you can't see it from the surface of the water,
32
133880
3376
02:17
you can't see it in satellite images,
33
137280
2456
02:19
so how do we know it's there?
34
139760
2176
02:21
Well, a trawler can tell you,
35
141960
2776
02:24
when she puts her net over the side and drags for 20 minutes
36
144760
4336
02:29
and comes up empty,
37
149120
1816
02:30
that she knows she's in the dead zone.
38
150960
2296
02:33
And she has to go somewhere else.
39
153280
2336
02:35
But where else do you go if this area is 8,000 square miles big?
40
155640
5856
02:41
About the size of the state of New Jersey.
41
161520
2440
02:44
Well, you either make a decision to go further,
42
164880
4256
02:49
without much economic return,
43
169160
2296
02:51
or go back to the dock.
44
171480
1480
02:54
As a scientist, I have access to high-tech equipment
45
174160
3936
02:58
that we can put over the side of the research vessel,
46
178120
2856
03:01
and it measures oxygen and many more things.
47
181000
2856
03:03
We start at the Mississippi River,
48
183880
2296
03:06
we crisscross the Gulf of Mexico all the way to Texas,
49
186200
4496
03:10
and even I sneak into Texas every now and then and test their waters.
50
190720
4640
03:16
And you can tell by the bottom oxygen --
51
196560
3736
03:20
you can draw a map of everything that's less than two,
52
200320
3176
03:23
which is the magic number for when the fish start to leave the area.
53
203520
5680
03:29
I also dive in this dead zone.
54
209880
2080
03:33
We have oxygen meters that we have to deploy offshore
55
213000
4016
03:37
that tell us continuous measurements of low oxygen or high oxygen.
56
217040
4400
03:42
And when you get into the water, there's a lot of fish.
57
222360
3576
03:45
Tons of fish, all kinds of fish,
58
225960
1896
03:47
including my buddy here, the barracuda that I saw one day.
59
227880
4216
03:52
Everybody else swam this way and I went this way with my camera.
60
232120
4376
03:56
(Laughter)
61
236520
1016
03:57
And then, down at 30 feet you start to see fewer fish.
62
237560
4616
04:02
And then you get to the bottom.
63
242200
2176
04:04
And you don't see any fish.
64
244400
2216
04:06
There's no life on the platform, there's no life swimming around.
65
246640
4656
04:11
And you know you're in the dead zone.
66
251320
2480
04:15
So, what's the connection between the middle of the United States
67
255000
4296
04:19
and the Gulf of Mexico?
68
259320
2096
04:21
Well, most of the watershed is farmland.
69
261440
3360
04:25
And in particular, corn-soybean rotation.
70
265720
3760
04:30
The nitrogen that is put in fertilizers and the phosphorus goes on the land
71
270959
5657
04:36
and drains off into the Mississippi River
72
276640
2976
04:39
and ends up in the Gulf of Mexico.
73
279640
2200
04:42
There's three times more nitrogen in the water
74
282440
4816
04:47
in the Mississippi now,
75
287280
1776
04:49
than there was in the 1950s.
76
289080
2216
04:51
Three times.
77
291320
1416
04:52
And phosphorus has doubled.
78
292760
2016
04:54
And what that means is more phytoplankton and more sinking sails and lower oxygen.
79
294800
5080
05:00
This is not a natural feature of the Gulf; it's been caused by human activities.
80
300520
4480
05:06
The landscape is not what it used to be.
81
306040
2616
05:08
It used to be prairies and forests and prairie potholes
82
308680
4936
05:13
and duck areas and all kinds of stuff.
83
313640
4096
05:17
But not anymore -- it's row crops.
84
317760
2280
05:20
And there are ways that we can address this type of agriculture
85
320760
4976
05:25
by using less fertilizer, maybe precision fertilizing.
86
325760
5296
05:31
And trying some sustainable agriculture
87
331080
3416
05:34
such as perennial wheatgrass, which has much longer roots
88
334520
4536
05:39
than the six inches of a corn plant,
89
339080
2616
05:41
that can keep the nitrogen on the soil and keep the soil from running off.
90
341720
4600
05:47
And how do we convince our neighbors to the north,
91
347320
4016
05:51
maybe 1,000 miles away or more,
92
351360
3376
05:54
that their activities are causing problems with water quality in the Gulf of Mexico?
93
354760
6040
06:01
First of all, we can take them to their own backyard.
94
361760
3136
06:04
If you want to go swimming in Wisconsin in the summer
95
364920
3576
06:08
in your favorite watering hole,
96
368520
1800
06:11
you might find something like this
97
371200
3216
06:14
which looks like spilled green paint and smells like it,
98
374440
4496
06:18
growing on the surface of the water.
99
378960
2536
06:21
This is a toxic blue-green algal bloom
100
381520
3856
06:25
and it is not good for you.
101
385400
3040
06:29
Similarly, in Lake Erie, couple of summers ago
102
389480
4136
06:33
there was hundreds of miles of this blue-green algae
103
393640
3896
06:37
and the city of Toledo, Ohio, couldn't use it for their drinking water
104
397560
4336
06:41
for several days on end.
105
401920
1856
06:43
And if you watch the news,
106
403800
1736
06:45
you know that lots of communities are having trouble with drinking water.
107
405560
5920
06:53
I'm a scientist.
108
413440
1736
06:55
I don't know if you could tell that.
109
415200
2096
06:57
(Laughter)
110
417320
1240
07:01
And I do solid science, I publish my results,
111
421560
4096
07:05
my colleagues read them, I get citations of my work.
112
425680
4400
07:10
But I truly believe that, as a scientist,
113
430840
3880
07:15
using mostly federal funds to do the research,
114
435680
4976
07:20
I owe it to the public,
115
440680
3136
07:23
to agency heads and congressional people
116
443840
3496
07:27
to share my knowledge with them
117
447360
2576
07:29
so they can use it, hopefully to make better decisions
118
449960
3896
07:33
about our environmental policy.
119
453880
2160
07:36
(Applause)
120
456440
1976
07:38
Thank you.
121
458440
1256
07:39
(Applause)
122
459720
3696
07:43
One of the ways that I was able to do this is I brought in the media.
123
463440
4456
07:47
And Joby Warrick from the "Washington Post"
124
467920
4416
07:52
put this picture in an article
125
472360
2976
07:55
on the front page, Sunday morning, two inches above the fold.
126
475360
4000
08:00
That's a big deal.
127
480160
2256
08:02
And Senator John Breaux, from Louisiana,
128
482440
3256
08:05
said, "Oh my gosh, that's what they think the Gulf of Mexico looks like?"
129
485720
4216
08:09
And I said, "Well, you know, there's the proof."
130
489960
2656
08:12
And we've go to do something about it.
131
492640
2696
08:15
At the same time, Senator Olympia Snowe from Maine
132
495360
4736
08:20
was having trouble with harmful algal blooms in the Gulf of Maine.
133
500120
3896
08:24
They joined forces -- it was bipartisan --
134
504040
3896
08:27
(Laughter)
135
507960
1296
08:29
(Applause)
136
509280
2456
08:31
And invited me to give congressional testimony,
137
511760
2896
08:34
and I said, "Oh, all I've done is chase crabs around south Texas,
138
514680
3056
08:37
I don't know how to do that."
139
517760
1416
08:39
(Laughter)
140
519200
1216
08:40
But I did it.
141
520440
1216
08:41
(Cheers)
142
521680
1496
08:43
And eventually, the bill passed.
143
523200
1575
08:44
And it was called -- yeah, yay!
144
524799
2697
08:47
It was called The Harmful Algal Bloom
145
527520
3096
08:50
and Hypoxia Research and Control Act of 1998.
146
530640
4696
08:55
(Laughter)
147
535360
1456
08:56
(Applause)
148
536840
3336
09:00
Thank you.
149
540200
1216
09:01
Which is why we call it the Snowe-Breaux Bill.
150
541440
2496
09:03
(Laughter)
151
543960
1200
09:06
The other thing is that we had a conference in 2001
152
546400
6520
09:13
that was put on by the National Academy of Sciences
153
553800
2776
09:16
that looked at fertilizers, nitrogen and poor water quality.
154
556600
4320
09:21
Our plenary speaker was the former governor
155
561880
3616
09:25
of the state of New Jersey.
156
565520
1840
09:28
And she ...
157
568640
2136
09:30
There was no thinking she wasn't serious when she peered at the audience,
158
570800
4856
09:35
and I thought, "Surely she's looking at me."
159
575680
3136
09:38
"You know, I'm really tired of this thing being called New Jersey.
160
578840
4016
09:42
Pick another state, any state, I just don't want to hear it anymore."
161
582880
3856
09:46
But she was able to move the action plan
162
586760
3656
09:50
across President George H.W. Bush's desk
163
590440
5696
09:56
so that we had environmental goals
164
596160
2560
09:59
and that we were working to solve them.
165
599960
1960
10:04
The Midwest does not feed the world.
166
604000
3040
10:07
It feeds a lot of chickens, hogs, cattle
167
607880
5736
10:13
and it generates ethanol
168
613640
2256
10:15
to put into our gasoline,
169
615920
2376
10:18
which is regulated by federal policy.
170
618320
3000
10:22
We can do better than this.
171
622160
1480
10:25
We need to make decisions
172
625400
2240
10:28
that make us less consumptive
173
628880
4120
10:34
and reduce our reliance on nitrogen.
174
634840
4240
10:39
It's like a carbon footprint.
175
639920
2176
10:42
But you can reduce your nitrogen footprint.
176
642120
3016
10:45
I do it by not eating much meat --
177
645160
4400
10:50
I still like a little every now and then --
178
650360
2096
10:52
not using corn oil,
179
652480
1480
10:55
driving a car that I can put nonethanol gas in
180
655240
4416
10:59
and get better gas mileage.
181
659680
1800
11:02
Just things like that that can make a difference.
182
662520
2536
11:05
So I'm challenging, not just you,
183
665080
3656
11:08
but I challenge a lot of people, especially in the Midwest --
184
668760
3416
11:12
think about how you're treating your land and how you can make a difference.
185
672200
4960
11:18
So my steps are very small steps.
186
678040
2960
11:22
To change the type of agriculture in the US
187
682320
3696
11:26
is going to be many big steps.
188
686040
2896
11:28
And it's going to take political and social will for that to happen.
189
688960
3760
11:33
But we can do it.
190
693360
1320
11:35
I strongly believe we can translate the science,
191
695280
4176
11:39
bridge it to policy and make a difference in our environment.
192
699480
4480
11:44
We all want a clean environment.
193
704560
2456
11:47
And we can work together to do this
194
707040
2576
11:49
so that we no longer have these dead zones in the Gulf of Mexico.
195
709640
4296
11:53
Thank you.
196
713960
1216
11:55
(Applause)
197
715200
6080
About this website

This site will introduce you to YouTube videos that are useful for learning English. You will see English lessons taught by top-notch teachers from around the world. Double-click on the English subtitles displayed on each video page to play the video from there. The subtitles scroll in sync with the video playback. If you have any comments or requests, please contact us using this contact form.

https://forms.gle/WvT1wiN1qDtmnspy7