A shrimp boat. Shrimp can't survive in the oxygen-depleted water in the Dead Zone so the EPA is trying to control runoff. (Photo by Lester Graham)
The EPA has revised a plan to control polluted runoff from 31 states that
contribute to the Dead Zone in the Gulf of Mexico. But states say there needs to
be more money too. Chuck Quirmbach reports:
Transcript
The EPA has revised a plan to control polluted runoff from 31 states that
contribute to the Dead Zone in the Gulf of Mexico. But states say there needs to
be more money too. Chuck Quirmbach reports:
Fertilizers such as nitrogen and phosphorus run off farm fields in
the Mississippi River basin. The nutrients then wash down the river, leading to
excessive algae growth in the Gulf of Mexico. That creates a dead zone of
20,000 square kilometers that harms shrimp and other species.
An EPA task force has released a plan that puts the states in the lead role for
cutting nutrients. But panel member Russell Rasmussen says what’s missing are
the billions of dollars needed to shrink the Dead Zone by the stated target of
75%:
“There just haven’t been the resources brought to bear to achieve that goal and it
doesn’t look like they’re going to be there between now and 2015.”
The EPA says major environmental progress in the Gulf is less a question of cost
and more about public-private partnerships.
Corn requires more fossil fuel-based nitrogen fertilizer than many other crops. Tanks of pressurized anhydrous ammonia fixes nitrogen in the soil, but heavy rains can wash nitrogen into waterways. (Photo by Lester Graham)
Farmers are paid to put grassy strips to act as buffer zones along waterways. Some farmers don't sign up for the program. With higher corn prices and a moratorium on the program, more farmers might be tempted to plow right to the edge of streams. (Photo by Lester Graham)
In the fall and spring, farmers incorporate nitrogen into fields to fertilize crops. However, some of the nitrogen ends up polluting waterways. (Photo by Lester Graham)
Pressure to plant more corn for ethanol will mean about 12 million acres more corn this year. It will also mean more pressure to put land into production that should be set aside to protect the environment. (Photo by Lester Graham)
Government-funded programs that pay for
conservation on farmland have done a lot to
improve the environment over the past twenty
years. The federal government has paid farmers
to take some cropland and set it aside to protect
waterways and wildlife habitat. In the second of
our two-part series on ethanol, Julie Grant reports
that some of that conservation is being stalled:
Transcript
Government-funded programs that pay for
conservation on farmland have done a lot to
improve the environment over the past twenty
years. The federal government has paid farmers
to take some cropland and set it aside to protect
waterways and wildlife habitat. In the second of
our two-part series on ethanol, Julie Grant reports
that some of that conservation is being stalled:
A good hard rain can wash a lot of valuable soil off a farm field.
John Wallbrown grows corn and soybeans on his farm. He says losing
soil is just like losing money. The soil carries with it all the
nutrients he’s put in the fields to help the crops grow, things such as
nitrogen and phosphorous. Wallbrown says he’s put in a good number of
grass waterways through the fields to help filter the water and hold on
to that soil:
“And so when you put in a grass waterway, it dramatically reduces the
amount of erosion. And it is just better for the water supply, better
for our crop. We’re keeping our soil in our field as opposed to it
getting put away.”
What Wallbrown calls nutrients in the field are considered pollution
once they wash into rivers and lakes. So Wallbrown says planting grass
near waterways is good for everyone. Except it means he’s got to use
land that otherwise could be growing crops, and that’s a loss of
income.
Wallbrown has gotten various government assistance to offset those
losses. The largest program, is called the Conservation Reserve Program, known as the
CRP for short.
John Johnson is with the US Department of Agriculture. He says when
you add up all the farms like John Wallbrown’s around the country, the
CRP is making a huge difference in reducing agricultural runoff into
waterways:
“Over 450 million tons of topsoil annually are prevented from eroding
because of CRP. We’ve got lots of really good benchmarks and measurements of
success of CRP, in both water quality, soil erosion and wildlife
habitat.”
But that set-aside land is in demand these days. There’s been a huge
call for bio-fuels to help reduce American dependence on foreign oil.
Bio-fuels are made from crops such as soybeans and corn, especially
corn. So Johnson says the government has decided to stop enrolling
new farmland into the conservation program:
“The overriding concern was that there is a need for a larger supply of
corn and soybeans and wheat production right now, so given the need for
that production, let’s just take a pause right now from enrolling large
acreage of additional farmland into the CRP.”
Corn is used to make ethanol, a fuel that’s now commonly blended with
gasoline. That’s caused corn prices to nearly double so farmers say
they’re planting 12 million acres more corn this year than last year.
That’s the most corn grown in the US in more than 50 years.
Ralph Grossi, director of the American Farmland Trust, says corn needs a
lot more nitrogen fertilizer than other crops. And when it rains,
nitrogen moves quickly from the fields to the waterways. That’s
especially true when grass strips don’t filter the runoff.
Grossi says that nitrogen drains into creeks and rivers from 36 states
into the Mississippi River and eventually to the Gulf of Mexico. There
it causes huge algae blooms that then die, sink, and the decaying
matter causes low oxygen in the water called hypoxia. That’s why the
Corn Belt has been blamed for creating a huge dead zone in the Gulf of
Mexico each year:
“If you increase corn production and don’t add the conservation practices
it will add nutrients and exacerbate problems in the gulf with hypoxia.
But it’s not just in the gulf, it’s problems for every local water
district that has to purify water for drinking and other urban
purposes. As they have to contend with more nutrients, that increases
their costs of cleaning the water.”
Grossi says the best place to clean the water is at the source. He
says that’s why the government must continue to help farmers pay for
grass waterways and buffer strips – those things prevent farm nutrients
from getting into the water in the first place. He says the need for
grass waters is even greater now that so much farmland is being planted
in corn to meet the demand for more ethanol.
Small shrimp fishers are concerned about the Gulf of Mexico 'dead zone' because shrimp can't survive in the oxygen depleted water. (Photo by Lester Graham)
Some Midwest farmers leave no grass buffer between their fields and nearby streams, allowing excess nitrogen to easily enter the waterways. (Photo by Lester Graham)
Some farm fields drain stormwater from treated farm fields directly into nearby creeks that are tributaries of the Mississippi River. Scientists believe the fertilizer pollution contributes to the Gulf 'dead zone.' (Photo by Lester Graham)
The government has been working with agriculture, environmentalists and scientists to come up with a way to reduce the size of a ‘dead zone’ in the Gulf of Mexico. The dead zone causes problems for the fisheries in the Gulf. It’s believed the dead zone is caused by excess nitrogen on farm fields in the Midwest that’s washed to the Mississippi River and then to the Gulf. A government task force has determined that if the flow of nitrogen into the Gulf can be cut by 30 percent, the size of the dead zone can be reduced. The Great Lakes Radio Consortium’s Lester Graham reports… a new study predicts a 30 percent reduction won’t be enough to make a difference:
Transcript
The government has been working with agriculture, environmentalists and scientists to
come up with a way to reduce the size of a ‘dead zone’ in the Gulf of Mexico. The dead
zone causes problems for the fisheries in the Gulf. It’s believed the dead zone is caused
by excess nitrogen on farm fields in the Midwest that’s washed to the Mississippi River
and then to the Gulf. A government task force has determined that if the flow of nitrogen
into the Gulf can be cut by 30 percent, the size of the dead zone can be reduced. The
Great Lakes Radio Consortium’s Lester Graham reports… a new study predicts a 30
percent reduction won’t be enough to make a difference:
The idea that fertilizer used on a corn field in the Midwest can cause a ‘dead zone’ in the Gulf of Mexico
is hard to fathom. But when you realize that all or parts of 31 farm states drain into the
Mississippi basin, it becomes a little easier to understand. Excess nitrogen causes a huge algae
bloom in the Gulf. When the vegetation dies, it decays on the bottom and bacteria feed
on it. The huge expanse of bacteria depletes the oxygen.
Nancy Rabalais is a professor with the Louisiana Universities Marine Consortium. She
says most life under the water needs that oxygen to survive.
“The oxygen is depleted in the water column so that the fish and shrimp, anything that
can swim, leaves the area. All the indicators show that it’s gotten much worse since the
1950’s to present, and that’s consistent with the increase in nitrogen in the Mississippi
River.”
Since 1985, Rabalais has been measuring the size of the dead zone every year. The zone
ranges in size from about 2,000 square miles to about 10,000 square miles.
That’s about the size of Lake Erie.
Jerald Horst is a biologist with the Louisiana Sea Grant. He says it’s hard to know the
exact impact on life under the sea…
“Very difficult to say ‘Gee, this year the shrimp
production is down somewhat because of hypoxia,’ or whether the shrimp production is
down somewhat because of a host of other environmental factors.”
But the fear is the hypoxic zone could stop being a dead zone that shrinks and grows
– and one year disappeared altogether… and instead become a permanent dead zone where nothing would ever live. That’s happened in a few other places on the globe such
as the Black Sea. It’s not clear that the same kind of thing can happen in the Gulf, but
signs are ominous. Horst says upwellings of oxygen-starved water near the shore after a
storm used to be very, very rare. Lately, they’ve become more and more frequent. He
says it means the problem is getting worse.
There’s still a lot of debate about whether the dead zone in the Gulf is a serious problem.
But, at this point, most agricultural agencies and farm groups have stopped disputing the
science and whether their nitrogen is causing the problem. Now they’re trying to figure
out the best and cheapest way to deal with it.
The government task force that’s working on the problem has arrived at an Action Plan;
the task force has determined the amount of nitrogen getting into the Mississippi River
needs to be cut by 30 percent to reduce the Gulf zone by half in ten years.
Donald Scavia has been working on the problem. He was involved in the debate when he
was a senior scientist with the National Oceanic and Atmospheric Administration. He’s
retired from NOAA and now directs the Michigan Sea Grant. From his office at the
University of Michigan, Scavia explained how the task force arrived at the figure.
“We agreed to a 30 percent reduction because it was similar to what was done in other
places, probably acceptable to the community and will head us in the right direction.”
After arriving in Michigan, Scavia started research to determine if a 30 percent reduction
would do the job. Using three very different computer models, Scavia and his team
learned that they could actually predict the size of the dead zone from year to year…
“From that analysis, that not only looked at the size of the zone, but actually looked at
potential inter-annual variability caused by changes in climate, changes in weather say
that probably 35 to 45 percent nitrogen load reduction’s going to be needed to get to that
goal in most years.”
Scavia’s study was published in the journal Estuaries.
A 35 to 45 percent reduction is a much tougher goal than the 30 percent the task force is
recommending. As it is, states were planning massive artificial wetlands and extensive
drainage programs to soak up excess nitrogen before it got to the tributaries that fed the
Mississippi River. They also planned to get farmers to reduce the amount of nitrogen
they’re using. That’s a tough sell for a couple of reasons. First of all, it would have to be
voluntary because nitrogen use is nearly completely unregulated. Second, farmers
often use what they call an insurance application of nitrogen… they use a little more than
is actually needed to get a good crop, because nitrogen is relatively cheap. The excess
often ends up washed into ditches and streams and creeks and rivers… and finally to the
Mississippi and the Gulf of Mexico’s dead zone. So… cutting nitrogen flow into the
Mississippi by 30 percent was a huge task. Cutting nitrogen by as much as 45 percent… well… you can imagine…
For the Great Lakes Radio Consortium, this is Lester Graham.
Small shrimp fishers are concerned about the Gulf of Mexico 'dead zone' because shrimp can't survive in the oxygen depleted water. (Photo by Lester Graham)
Some Midwest farmers leave no grass buffer between their fields and nearby streams, allowing excess nitrogen to easily enter the waterways. (Photo by Lester Graham)
Some farm fields drain stormwater from treated farm fields directly into nearby creeks that are tributaries of the Mississippi River. Scientists believe the fertilizer pollution contributes to the Gulf 'dead zone.' (Photo by Lester Graham)
A new study predicts the government’s plan to reduce the size of the ‘Dead Zone’ in the Gulf of Mexico won’t be strong enough to make a difference. The Great Lakes Radio Consortium’s Lester Graham reports:
Transcript
A new study predicts the government’s plan to reduce the size of the “Dead Zone” in the Gulf of
Mexico won’t be strong enough to make a difference. The Great Lakes Radio Consortium’s
Lester Graham reports:
The Dead Zone in the Gulf is believed to be caused by excess nitrogen used by farmers in the 31
states that drain into the Mississippi and ultimately into the Gulf of Mexico. The Dead Zone
causes problems for the fisheries in the Gulf. A study published in the scientific journal, Estuaries, predicts that an Action Plan put together by a government task force might not
go far enough. Michigan SeaGrant director Donald Scavia used computer modeling in the
study…
“What we tried to do here is take three different, very different models and ask the same question
of those models to try to get an answer.”
The answer was the same… the government task force plan to reduce the amount of nitrogen
reaching the Mississippi River by 30 percent is not enough. The models indicated a 35 to 45
percent reduction is needed to shrink the Dead Zone by half in the next ten years.
For the Great Lakes Radio Consortium, this is Lester Graham.
Although government programs offer incentives for farmers to plant grassy buffers between farm fields and waterways, many farmers don't bother with the voluntary efforts to reduce nitrogen. A new push to reduce nitrogen runoff is in the works in an effort to reduce the size of a 'Dead Zone' in the Gulf of Mexico believed to be caused by excess nitrogen runoff from Midwest farms. (Photo by Lester Graham)
The government is looking at programs to reduce the amount of fertilizer runoff from farms that ends up in streams and rivers. It’s necessary because 41 percent of the continental U.S. drains into the Mississippi River and all that runoff is dumped into the Gulf of Mexico. There, it’s causing a ‘dead zone’ where fish and other aquatic life can’t live. The Great Lakes Radio Consortium’s Lester Graham reports:
Transcript
The government is looking at programs to reduce the amount of fertilizer runoff from farms that
ends up in streams and rivers. It’s necessary because 41-percent of the continental U.S. drains
into the Mississippi River and all that runoff is dumped into the Gulf of Mexico. There it’s
causing a ‘dead zone’ where fish and other aquatic life can’t live. The Great Lakes Radio
Consortium’s Lester Graham reports:
Each year about one-and-a-half million metric tons of nitrogen is dumped into the Gulf of
Mexico. Plants feed on nitrogen, so there are huge algae blooms, far more than the tiny aquatic
animals that feed on algae can eat. The algae eventually dies and begins to decompose. That process
depletes oxygen from the water. Fish and other marine life need oxygen to live. So they leave
the oxygen-depleted area or die. It’s called a ‘dead zone.’ In recent years that ‘dead zone’ in the
Gulf of Mexico has been as large as the state of New Jersey.
Don Scavia is Chief Scientist with the National Oceanic and Atmospheric Administration’s
National Ocean Service. He says it looks as though much of that nitrogen comes from farms in
the Mississippi basin.
“The most significant change in the nitrogen load into the basin is actually coming from
agricultural application of fertilizer. That application rate has more than tripled since the 1950’s,
corresponding to almost a tripling of nitrogen loss from that system into the Gulf.”
Farms that are hundreds of miles from the Mississippi River drain into the Mississippi River
basin. The basin stretches from Montana to the southwest tip of New York. It includes all or
parts of 31 states.
Nitrogen exists naturally in the environment. But growing corn and some other crops on the
same land year after year depletes nitrogen. So farmers fertilize the land to bolster nitrogen
levels. Sometimes they use animal manure, but often they use man-made fertilizers such as
anhydrous ammonia.
David Salmonsen is with the American Farm Bureau.
“Well, for several crops, especially out into the upper parts of the Mississippi River basin, the
Illinois, Indiana, Iowa, southern Minnesota, the great Corn Belt, you need nitrogen as a basic
additive and basic element to grow, to grow these crops.”
But often farmers use more nitrogen than they really need to use. It’s called an “insurance”
application. Farmers gamble that using an extra 10 to 20 pounds of nitrogen fertilizer per acre
will pay off in better crop yields – more corn. A lot of times, that gamble doesn’t pay off because
rain washes the extra nitrogen off the field. Salmonsen says slowly farmers are moving toward
more precise nitrogen application.
“Try and get away from what, you know, for years has been a practice among some people, they
say ‘Well, we’ll do what they call insurance fertilization. We got to have the crop. It may be a
little more than what we need, but we’ll know we have enough,’ because they just didn’t have the
management tools there to get this so precisely refined down to have just the right amount of
fertilizer.”
Salmonsen says with global satellite positioning tools, computers, and better monitoring farmers
will soon just be using the nitrogen they need. But, it’s not clear that farmers will give up the
insurance applications of nitrogen even with better measurements.
The government is getting involved in the nitrogen-loading problem. A task force has been
meeting to determine ways to reduce the amount of nitrogen that reaches the Gulf of Mexico.
Among the strategies being considered are applying nitrogen fertilizer at lower rates, getting
farmers to switch from row crops to perennial crops so they don’t have to fertilize every year,
planting cover crops during fall and winter to absorb nitrogen, establishing artificial wetlands in drainage areas to absorb nitrogen and getting
farmers to plant buffer strips of grass between farm fields and nearby waterways to filter out nitrogen.
Tom Christiansen is with the U.S. Department of Agriculture. He says while the government task
force is considering recommending some specific basin-wide reductions in nitrogen use the
USDA is only looking at the problem farm-by-farm.
“We get good conservation on the land, good water quality in the local streams and that will
benefit the Gulf. So, we’re working on a site-specific basis. We haven’t established any kind of
nation-wide goal for nutrient reduction.”
Unlike other industries, the government is reluctant to mandate pollution reduction. Instead of
regulations and fines used to enforce pollutions restrictions with manufacturing, agriculture is
most often encouraged to volunteer to clean up and offered financial incentives to do that. But in
the past farmers have complained that there wasn’t enough money in the programs. Christiansen
says the new farm bill has more money for conservation efforts and that should make it more
appealing for farmers to reduce nitrogen pollution.
“It falls back to good conservation planning, using the correct programs and then providing the
right kind of incentives and benefits to producers because they are taking land out of production
in many cases.”
The government is assuming the voluntary programs will be enough to reduce the nitrogen flow
into the Gulf of Mexico. No one expects the ‘dead zone’ will be eliminated. The best that
they’re hoping for is that it will be significantly reduced.
For the Great Lakes Radio Consortium, this is Lester Graham.
Although government programs offer incentives for farmers to plant grassy buffers between farm fields and waterways, many farmers don't bother with the voluntary efforts to reduce nitrogen. A new push to reduce nitrogen runoff is in the works in an effort to reduce the size of a 'Dead Zone' in the Gulf of Mexico believed to be caused by excess nitrogen runoff from Midwest farms. (Photo by Lester Graham)
A government task force is trying to find ways to reduce fertilizer pollution from Midwest farms because it’s causing environmental damage to the Gulf of Mexico. The Great Lakes Radio Consortium’s Lester Graham reports:
Transcript
A government task force is trying to find ways to reduce fertilizer pollution from Midwest farms
because it’s causing environmental damage to the Gulf of Mexico. The Great Lakes Radio
Consortium’s Lester Graham reports:
The task force is looking at ways to stop excess nitrogen from getting into waterways. It hopes to
persuade farmers to reduce the amount of nitrogen they use or plant grassy buffer strips or
artificial wetlands to take up the nitrogen. The idea is to stop so much nitrogen getting into the
Gulf of Mexico. Once there it causes an algae bloom that then dies and depletes the water of
oxygen, causing a ‘dead zone.’
Don Scavia is with the National Oceanic and Atmospheric Administration’s National Ocean
Service. He says offering farmers money to sign up for conservation programs is likely the best
route.
“The idea is to try to make the social benefit of reducing the nitrogen load work in favor of the
farmers.”
Right now, many row crop farmers pay the cost of applying more nitrogen than needed in hopes
of getting a better crop. Experts say it’s a gamble that rarely pays off and ultimately adds to the
problem in the Gulf.
For the Great Lakes Radio Consortium, this is Lester Graham.
Commercial shrimpers and fishers in the Gulf of Mexico cannot find anything alive in the 'dead zone.' Research indicates fertilizer runoff from Midwest farms causes the 'dead zone.' (Photo by Lester Graham)
Farmers and lawn care companies in the Midwest use fertilizer to grow better crops and greener lawns. But excess fertilizer is washed downstream by rain, eventually reaching the Gulf of Mexico. Scientists say once in the Gulf, it triggers a process that causes a so-called ‘Dead Zone.’ The Great Lakes Radio Consortium’s Lester Graham reports:
Transcript
Farmers and lawn care companies in the Midwest use fertilizer to grow better crops and greener
lawns. But excess fertilizer is washed downstream by rain, eventually reaching the Gulf of
Mexico. Scientists say once in the Gulf, it triggers a process that causes a so-called ‘Dead Zone.’
The Great Lakes Radio Consortium’s Lester Graham reports:
To get better crop production farmers use anhydrous ammonia to increase nitrogen levels in the
soil. To get greener lawns, homeowners use fertilizers that also can increase nitrogen and other
nutrient levels. But excess nitrogen gets carried away by rainstorms. For all or parts of 31 states,
that nitrogen is washed into ditches and creeks and rivers that are all part of the Mississippi River
basin. All of that land drains into the Mississippi and the Mississippi drains into the Gulf of
Mexico.
Tracy Mehan was the U.S. Environmental Protection Agency’s Assistant Administrator for
Water. Mehan points out that’s a lot of runoff that ends up in one place…
“It affects most of the inland drainage of the United States from Minnesota, from Ohio, from
Nebraska, Missouri, Iowa, Illinois all the way down to the Gulf of Mexico. So, we’re dealing
with a tremendously broad system here and with tremendous challenges to protect the Gulf of
Mexico.”
Challenges because the nitrogen and other nutrients cause a problem.
Nancy Rabalais is a professor with the Louisiana Universities Marine Consortium. She says the
nitrogen causes a huge bloom of algae…
“Well, the nutrients stimulate the growth of plants just like fertilizers stimulate the growth of a
corn plant. But the plants in the Gulf are microscopic algae.”
Some of the algae is eaten by tiny aquatic animals and fish. But, with a huge algal bloom… some
of it just dies and sinks to the bottom. Those algae cells are consumed by bacteria that also
consume oxygen. Rabalais says that depletes the oxygen in the surrounding water…
“So what basically happens is that the production of algae is just too much for the system to
handle.”
This oxygen starvation is called hypoxia. Marine life can’t live in a hypoxic area. Fish avoid it if
they can by swimming away. Other life that can’t move that fast dies. The size of the hypoxic
zone varies from year to year. Weather across the nation affects the amount of runoff that ends
up in the Gulf, but the trend has been a dead zone that’s gotten bigger over the past twenty
years… and according to Rabalais’ research it has doubled in size since the 1950’s when nitrogen
started being used extensively in agriculture.
(sound of boat engine starting up)
In Louisiana, the commercial fishers and shrimpers are concerned about the ‘dead zone.’ Some of
the smaller operations find it difficult to travel the longer distances to find fish outside the ‘dead
zone.’
Nelwyin McInnis is with the environmental organization, the Nature Conservancy. Walking in a
marsh area in Louisiana, she talked how important it was to that region that farmers and
homeowners in the Midwest do something to try to cut back on the amount of fertilizer that ends
up in the Gulf of Mexico.
“Certainly any ways that you can reduce the fertilizer runoff would certainly be of value. And I
know each farmer can’t imagine their impact hundreds of miles away in the Gulf of Mexico, but
each one adds up and has an effect.”
But powerful agricultural interests say the ‘dead zone’ in the Gulf of Mexico is not caused by
nitrogen fertilizers in the farm belt. The American Farm Bureau has kept up a steady campaign
of denial of responsibility. Reports and essays published by the Farm Bureau question researcher
Nancy Rabalais’ findings. Rabalais says the Farm Bureau can question her all it wants. Her
published work has been reviewed by other scientists in close to a dozen major scientific journals.
“We don’t believe in collecting data and putting it on a shelf. We get it to the scientific public and
we also try to translate it so that the public, including the agricultural community can understand
what it’s saying.”
Whether the agriculture community wants to hear what those data are saying is another question.
However, the government is taking it seriously and is looking at ways to reduce the amount of
nutrients being washed into the Gulf of Mexico.
For the Great Lakes Radio Consortium, this is Lester Graham.
Commercial shrimpers and fishers in the Gulf of Mexico cannot find anything alive in the 'dead zone.' Research indicates fertilizer runoff from Midwest farms causes the 'dead zone.' (Photo by Lester Graham)
The commercial fishers in the Gulf of Mexico are hoping the farmers in the Midwest help them solve a problem. The fishers and shrimpers say the farmers could help reduce a so-called ‘dead zone’ in the Gulf. The Great Lakes Radio Consortium’s Lester Graham reports:
Transcript
The commercial fishers in the Gulf of Mexico are hoping the farmers in the Midwest help them
solve a problem. The fishers and shrimpers say the farmers could help reduce a so-called ‘dead
zone’ in the Gulf. The Great Lakes Radio Consortium’s Lester Graham reports:
The ‘dead zone’ in the Gulf of Mexico varies in size from year to year, sometimes getting larger
than the state of New Jersey. Scientists say excess nitrogen and other nutrients used to grow
crops and lawns in the Midwest are drained from the Mississippi, Missouri, and Ohio river basins
and into the Gulf. Nancy Rabalais is a researcher with the Louisiana Universities Marine
Consortium. She says the result is a huge algae bloom in the Gulf…
“The nutrients stimulate the growth of these algae and they’re either eaten by zooplankton or fish
and become part of the marine food web or they die and sink to the bottom. It’s the cells that sink
to the bottom that eventually lead to the consumption of oxygen by bacteria.”
Fish and shrimp can’t live in the oxygen-starved area. The researchers say the only thing that can
reduce the size of the ‘dead zone’ is to reduce the amount of nitrogen from the Midwest that drains
into the Gulf of Mexico.
For the Great Lakes Radio Consortium, this is Lester Graham.
A recent study from the Louisiana Universities Marine Consortium shows the dead zone in the Gulf of Mexico is getting bigger. The Great Lakes Radio Consortium’s Jonathan Ahl reports that pollution from the Midwest may be to blame:
Transcript
A recent study from the Louisiana Universities Marine Consortium shows the dead zone in the Gulf of Mexico is getting bigger. The Great Lakes Radio Consortium’s Jonathan Ahl reports that pollution from the Midwest may be to blame:
The 85-hundred square mile area suffers from hypoxia. That’s when the levels of dissolved oxygen fall low enough to kill off most fish and plants. Many scientists believe nitrogen coming from Midwest farms and wastewater plants that travel down the Mississippi River are responsible. Forrest Peterson is a spokesperson with the Minnesota Pollution Control Agency. He says Midwestern states are aware of the problem, and are trying to fix it:
“Things like providing buffer strips and projects to retain some of the water’s nutrient management, things like that. So there are a whole array of things that can be done and that are being done, it just takes some time to see that effect.”
Peterson says the federal government has set the goal to reduce the zone to two thousand square miles and reduce nitrogen levels in the Mississippi River by 30 percent by 2015. For the Great Lakes Radio Consortium, I’m Jonathan Ahl.
A shrimp boat. Shrimp can't survive in the oxygen-depleted water in the Dead Zone so the EPA is trying to control runoff. (Photo by Lester Graham)
