CHAPTER 10
Into the Gulf of Mexico
The black lines and arrows show the flow of current in the Gulf of Mexico.
CHAPTER 10
a bayou
photo: world atlas.com
Dorp and Sam made their way past New
Orleans, and into the Mississippi River Delta, the place where the
Big Muddy (another name for the Mississippi River) entered the Gulf
of Mexico.
The water moved very slowly there.
The
delta is part dirt beach, part swamp and part mud hole. The size of
the delta varies from year to year, depending on how much silt is
deposited by the Mississippi, and how aggressively the currents of
the Gulf of Mexico pull that silt into the sea. Silt is the dirt in
the water that rainwater washes into any river or creek that feeds a
river. The Mississippi delta currently has about 3 million acres of
wetlands, which is about 40% of US wetlands.
“Sam,
look at how slow the water moves here in the delta.”
“We’re
almost at a snail’s pace, Mr. Dorp. No, I take that back. There’s
a snail on the tree root over there and it’s beating us. Wow!
I thought New Orleans sat right on the Gulf of Mexico. What gives?”
“Well,
Sam, “This is how river deltas are formed. As dirt from farmland
upstream is loosened by farm equipment and washed away by rain, it
comes down here. The dirt also comes from clothes being washed and little boys taking baths. The dirty water hits a flat, wide area and spreads
out, which makes it flow more slowly. This is what creates wetlands and bayous. This causes its sediment to
drop and become part of the wetlands here in the river delta. As silt
pushed this delta farther into the Gulf of Mexico over past couple of
centuries, it made New Orleans go further inland. The city hasn’t
moved, the delta has grown out, like your mother’s belly when she
was growing Abby.”
Sam
whistled, “And Mom sure did grow, but she sure didn’t like being
told she was getting big."
“Now,
Sam, since better erosion control programs are being put into place
upstream, the delta is currently shrinking and environmental groups
here are concerned because of the wildlife that needs the wetlands.”
“Isn’t
less soil erosion a good thing”
“Most
people would say yes, Sam; but ‘the wetlanders’ down here say
they need erosion to maintain their wetlands.
“I’ve
heard this is where Cajuns live,” Sam went off on a tangent. “Who
are Cajuns?”
Dorp
explained, “Cajuns, first called Arcadians, are a people-group who
originated in France and helped settle the area in Canada around Lake
Champlain. The British and French had a series of boundary disputes
in the 1700s. The British pushed back the French in certain areas.
The French settlers, the Arcadians, refused to swear loyalty to the
British Government. Long story short, these folks were removed from
that area and wound up here in Louisiana, which was controlled by Spain at
the time. They moved into the area before the US purchased the land.
How do you know about Cajuns?”
“At
school.”
"Good, when
your great-grandparents went to school, they probably read the poem 'Evangeline',
by Henry Wadsworth Longfellow. It tells of the dispersal of the
Arcadians from the northeast. Look
smart young man; we are entering the Gulf of Mexico.”
“What?
Do I look stupid now? You and I look alike right now, y’know!”
“Sam,
‘Look Smart’ is a British term that means one should do something
quickly.”
“Oh.”
The
last town they saw on the river was a little place called Pilottown,
Louisiana. No one lives there permanently, but it is a check-in point
for ships before heading up the Mississippi. Ship captains can’t
just go up the river by themselves, because the river bottom is
always changing depths because of river currents. Pilottown provides ship pilots that know the
river well to guide each ship going upstream.
They
entered the Gulf and Dorp introduced Sam to the
dead zone. It is a stretch of
water along the coast where marine life can’t find enough oxygen to
live. The condition is called
hypoxia.
Sam
asked, “What takes the oxygen out the water? The river and the
river delta have life. Why not the Gulf?
Dorp
explained that along with the river water comes sediment, effluent,
and fertilizers. This effluent and fertilizer helps certain algae in
the Gulf grow very fast. They are short-lived, and when they die,
they decompose, just like other life forms. Organic decomposition is
a chemical process that requires oxygen, then release CO2. The oxygen in the water is
used up and fish and other life forms don’t have enough oxygen to
breathe. The little scavengers get the oxygen, and the big fish and
shellfish can’t get enough to live on. The result is this dead
zone.
“How
does this problem get solved?”
Dorp
said.
“Some good news here, Sam. Farmers upstream used to apply
fertilizers according to charts that may not reflect a farm’s
individual topography and soil conditions. Many farmers are now
experimenting with application rates to see how little fertilizer
they can put on and still hit their yield targets. Some farmers have
reduced fertilizer usage substantially and thereby increased their
profits and put less fertilizer in their rivers. Besides this, farmers are also growing vegetative buffer strips and grassy
waterways in their fields. These are zones situated between the
cropland and the watercourse. They help trap fertilizer, herbicides,
pesticides, and eroded topsoil.
All these things are very helpful and are
helping to reduce the size of this dead zone in the Gulf.
“So
the dead zone can change?”
“Absolutely,
Dorp said. “Remember that dead zones are created by algae
responding to both natural and manufactured fertilizers in the delta
runoff. When the fertilizer levels subside, the ecology of the water
changes. The dead zone in the gulf shrinks during droughts upstream
because there is less rain to wash fertilizer into the river system.”
Sam
thought out loud. “You know; I’ve seen soil erode on grandpa’s
place. It always washes downhill. If fertilizer washes downhill, why
not just put less fertilizer on the bottoms of the hill? Then the
stuff that washes down would take care of the bottom of the hill.
“Sounds
like you’ve got a topic for next year’s science fair, Sam.
See if
farm chemicals predictably migrate downhill by rainfall, so fewer
chemicals can be applied on the lower elevations. Perhaps your
Grandpa Ed can help with you with that this summer.”
“Maybe
so. Where are we headed now?”
“We
are going to be taken out into the Gulf, where I suspect we will be
picked up by the Gulf Loop Current, which will connect with the Gulf
Steam and take us up the East coast of the US.”
“How
does that work, Mr. Dorp?”
Dorp
explained to Sam that there are consistent currents in large
bodies of water.
In the North Atlantic Ocean, the North Equatorial
Current moves from right to left along the equator,
then hits South
America and is pushed north.
This creates a rotation that that moves
up the eastern part of the US and is called the Gulf Stream.
Off New
England, the Gulf Stream runs contra-parallel to the Labrador Current
off the upper eastern seaboard
and heads east toward Europe and
becomes the North Atlantic Drift.
It then goes south down the west
coast of Europe where it becomes the Canary Current.
and then again
joins the North Equatorial Current.
All these currents put together,
act as a force called the North Atlantic Gyre.
The gyre is split by
the West Indies Island chain.
The left side of the current moves into
the Gulf of Mexico and loops though the Gulf.
Every
few months, the Gulf Loop shortens.
The cutoff current maintains its
energy for a while and spins toward Texas or Mexico.
These cutoffs
are called eddies.
If a tropical storm crosses paths with an eddy,
the energy from the eddy can intensify the storm.
Dorp
and Sam went farther into the Gulf and indeed the Loop was at its
longer stream, so it looked like they would move around the tip of
Florida and move up the coast.
They saw an offshore oil rig.
Sam
saw the rig and asked, “So what does an oil spill do to the water
in the Gulf?”
“On
a purely chemical basis, Sam, the oil does nothing to the water,
because the water can evaporate and be free of the oil.
The greater
question is to ask what the oil does to the ecosystem of the Gulf.
That can be a lot.”
“Are
oil companies bad guys? A lot of people say they are.”
“Well,
Sam, oil companies are run by humans. Humans can make honest
mistakes, which cause problems. Humans can also be greedy, which
causes more problems. Companies often reflect the attitudes of the
customers that support them. American humans want inexpensive luxury
that won’t harm the environment. Oil companies drill in the Gulf to
meet expected long-term needs for oil.
Only those who bicycle or walk
everywhere have a right to protest oil strategies; yet even pure
pedestrians rely on petroleum to stock the shelves in their grocery
stores and haul their dead to the cemetery."
"Nearly everyone who uses
petroleum wastes petroleum. Can things be done better?
Absolutely, but let the protesters first live waste-free and accident-free lives
on a personal level to show others how it’s done. Activists should
lead the way.”
“Wow.
As my grandpa would say: ‘Who stepped on your tail, kitty cat?’”
“Sam,
it bothers me when anyone expects more from others than they will
give of themselves. People in big houses can’t be true
environmentalists. A LEED mansion uses more energy that its
inhabitants should be allowed. People who want to alter the energy
climate should never vacation farther than they can walk or bicycle,
and even then, they need to acknowledge that the rubber for their
shoes and bicycle tires was shipped to America on a fuel-consuming barge from South America.”
“Ahem,
we are now moving along the Gulf Coast and are under the panhandle of
Florida.”
“Another
panhandle? Oklahoma has a panhandle, Nebraska has a panhandle, and
now Florida has a panhandle?”
“Sam,
you forgot to mention Idaho, West Virginia, Texas and Alaska. They
also have panhandles. A panhandle is an extension of the land mass
that resembles the handle of a frying pan.”
“Hmmm.
Speaking of frying pans, what’s cooking in Florida? Ha! What do
they grow there?”
“Food
again? I suppose some habits are hard to break. Florida grows
citrus and berries, seafood and shellfish, vegetables and beef, among
other things. As I said before, we are under the panhandle of
Florida, just under the state of Georgia.”
“I
have a Florida-type joke. What do you get when you cross a citrus and
a paramedic?
Dorp
allowed yet another bad joke, “I don’t know; what?”
“Lemon-aid!”
“Sam,
just ahead is the mouth of the Apalachicola River, which accepts water from the
Chattahoochee River. The Chattahoochee acts as the boundary between
the lower halves of Georgia and Alabama. The western part of Georgia
drains into the Gulf of Mexico, and the eastern part drains into the
Atlantic Ocean.
Sam
thought, “Hey! I know about the Chattahoochee River. My Grandpa Ed
worked on that river when he was young.
He lived
in La Grange, Georgia and worked on the West Point Dam Project in the
1970’s when they built a dam and a power plant.”
“Really.
What did your Grandpa Ed do?”
“He
worked for a company that cut trees. The Army Corps of Engineers
built a dam and flooded about 30,000 of acres of valley land with a
lot of trees. They partly flooded the valley behind the dam, and then
the crews went in, in flat-bottom boats and with chain saws, to cut
the trees to make a place for the fish that would live there. When
the trees were cut, they raised the water level up to the proper
level.
Dorp
thought, “Cutting trees from a boat? That must have been an
interesting job.”
“Yeah;
I hope I can do that someday."
"Your
Grandpa Ed traveled around.”
"He
said he was looking for Grandma, even though he hadn’t met her
yet.”
“I
suppose that’s sweet. We’ll be near Miami early next week.”
“We’ll
be in Yourami next week?”
Dorp
sad, “No; I said we’ll be to Miam.. Oh stop that, Sam!”
(boy-giggle).
“But
before we get to Ourami, Sam, we will see the Florida Everglades. Meanwhile, we have time to talk about water safety.
Let’s talk
about babies, since you look after Abby a lot. Do you know how to
keep babies safe around water?”
“Let’s
see; keep the toilet lid shut and the bathroom door shut. Don’t
leave kids alone anywhere there is water, especially babies in a bathtub. Don’t leave water in buckets that a baby can fall into…”
Dorp
kept asking questions. “When can a child be left alone in a
bathtub? You are by law, still a child.”
“Maybe
when they are old enough that they don’t want to be seen naked?”
“Perhaps.
Even so, there should be regular voice communication between parent
and child.
Also, make
sure the scald control on fixtures are set properly and working. Baby
skin burns easier than adult skin.
Pools and hot tubs should have
fences with self-closing gates that small children can’t open,
and
no one should enter a pool or hot tub without telling someone first;
even adults.”
Children
should not be in a pool when it is being drained and running near
the pool should be discouraged.
Babies should wear swim diapers when
taken into a private or public pool.”
“Why
are swim diapers important?”
“Because
Sam, a soiled diaper can leaks feces, excuse me; poop, into a pool
can cause RWIs, (Recreational Water lllnesses),
including
Cryptosporidium, Giardia, Shigella, norovirus and E. coli O157:H7.
“Yuk.
Cholera and typhoid? “
“Possibly, if the child is infected.”
“Wait!”
Sam recoiled. “We were in a dandelion, in a pasture, filled with
horses and horse poop. The horses eat the plants in the field. My dad
says that manure, another name for poop, feeds the grass and weeds.
So why don’t the germs go through the plant and make the horse
sick?
“Excellent
question, Galileo. Remember when we went into that root? We were
absorbed by osmosis; drawn in. But do you remember that there were
germs, and other things in the soil? They couldn’t get into the
roots because they were bigger than the tiny holes that absorbed us.
The skins of the cells that absorb water and nutrients keep out the
germs. Later in this trip, you’ll learn how humans have learned how
to imitate nature to purify water by a process called reverse
osmosis.”
“OK,
Mr. Dorp, back to water safety. What about water safety for older
kids?”
“If
you play in water, learn how to swim and stay in water that matches
your swimming ability.
Don’t dive into water until you know the
underwater terrain.
And don’t try to stunt-ride your bike into a
pool or pond.”
“For
adults; anyone in a boat should wear life jackets all the time in the
boat.
Don’t drink alcohol on the water, as a swimmer, as the
operator of a boat, or a passenger.
Don’t swim alone and be aware
that cold water can cause bad muscle cramps.
Last but not least,
weather hazard warnings should be heeded.
A lot of people die because
they ignore severe weather warnings.”
“Aye-aye
Cap’n.”
“We
are just outside of Tarpon Springs, Florida, Sam. This town once had
a great sponge harvesting industry until the waters here suffered a
red algae poisoning that killed the sponges. Did you know that real
sponges are water animals? They have porous bodies that allow
currents and tides to push water through them, so they can absorb the
food.”
“I’ve
seen my mom sponge paint. Moms get really excited when you try to help
while they are talking on the phone.”
Dorp
shook his head. “I’m sure.”
After
a time, Dorp and Sam approached the Everglades. The Everglades are
part of the Belle Glade
Watershed Basin and begins
toward the east side of Florida, near Orlando, though the actual
Everglades reserve is on the southwest corner of the state. The Belle
Glade Basin is named after a native people group who lived in its
northern region when the Spanish arrived. They were killed by disease
or absorbed into the slave population by the 1760s, when the Spanish
left the area.
They
floated past Cape Romano and saw Everglades, Florida, a town of about
500 people. The early tide pushed our travelers through the keys and
up toward the shore of the town, in front of the airstrip. They
mingled with the freshwater coming from the Barron River into the
Chokoloskee Bay.
“Well
Sam, we’re in the Florida Keyes now.”
“Why
are these things called keys?” Sam asked.
“It’s
a rendering of the Spanish word cayos,
which means ‘islands.’ And unlike the Mississippi River Delta
area that is made of sediment-muck, the Florida Keys are founded on
coral structures, so they are a sea structure next to the land, not a
land structure in the sea.”
“Then
they can’t erode like the Mississippi River Delta south of New
Orleans does?” asked Sam
“Correct.”
“What
kinds of fish live here?”
“Not
just fish live in these waters,” accounted Dorp.” Manatees, often
called sea cows, live in the area. They are herbivore mammals who
need warm water to survive. People even put manatees in canals to
keep down the vegetation. Some of the fish that live here are the
snook, grouper, drum, bass, snapper, redfish and tarpon, just to name
a few. Look to your left; there is a snook. See the long, dark line
that runs from the top of its head to the middle of its tailfin?
Human fishers say they are a good tasting fish and fun to catch,
whatever that means.”
"Mr.
Dorp! It is so cool to catch a fish to put a hook in water where you
can’t see anything, then have a fish take the bait and then fight
you all the way in.”
“Okay…
One of the strangest fish in the world lives here, the tarpon. Humans
love to catch it, but because it is so bony, they don’t keep it;
they just toss them back. That’s how many human males treat human females. Anyway, tarpons live in both saltwater and freshwater. They can grow
to 8’ long and weigh over 250 pounds. At a certain stage of their
lives, young tarpons do not search for food, but absorb nutrients
through their skin.”
“I
wish I could do that,” Sam blurted out. “Just stick my finger in
an apple pie and eat it that way.”
“Anyway;
tarpons are odd fish. They can drown or suffocate if held completely
underwater. Their breathing apparatus is tied into their flotation
bladders, and they come to the surface to ingest oxygen. Odd
creatures indeed, as fish go.
"The
Everglades is also home to such beautiful things as the Florida
panther and the ghost orchid. Oh, the outgoing tide has pulled us
back into the Gulf, and we will likely continue through the Keys and
round the point tip of Florida in a few days.
The Florida Everglades
is largest tropical wetlands in the US but is only about half the
size it was before developers moved in, claiming much of the northern
land for human use. The strange thing is, as much as people here
dislike hurricanes, those hurricanes have been very helpful in
slowing the rate of human development here.
No hurricane cares what
any rich man thinks.”
“Hmm.
The land sure looks flat here. “
“Very
flat. It is 250 miles from Orlando to the southern tip of Florida,
yet Orlando is just 100’ above sea level. Here we go around the
point of Florida, between the Upper Matecumbe Key and the Lower
Matecumbe Key.”
Dorp
and Sam were pushed by the Gulf Loop into the Gulf Stream just below
Theirami, er…Miami.
Sam
got goofy and began to chant a little sing-song gibberish:
“Matecumbe
– Ritacumbe – Deltacumbe – Thetacumbe – Laaaaa-deeee-da…
Dorp
said to him,
“You should be careful about speaking words you don’t
know. You just began a conversation with a Greek-speaking Caribbean
girl.”
“Really,
Mr. Dorp?!
Dorp
just smirked and waited to corner the tip of Florida.
Photo: ScienceDirect.com