The Importance of
Coastal Wetlands
http://www.uwgb.edu/biodiversity/econotes/2003/bradwetland2.jpg
The most common coastal
wetlands are swamps and
marshes.
Swamps are wetlands with mainly trees and
shrubs. There is standing water with limited
drainage.
http://www.sptimes.com/2006/03/31/images/state-swamp.jpg
Marshes are wetlands that are almost
always flooded and have a mixture of
cattails, reeds and other water plants.
http://farm1.static.flickr.com/79/231704069_8f7fcb83eb.jpg
What do coastal wetlands
do for us?
http://www.parkweb.vic.gov.au/education/endangered_species/images/activities/bd11-wetlands.jpg
Water Quality: Wetlands are one of nature's
most efficient water filters. Wetland plants and
soils clean the water before it goes into
groundwater or into rivers.
http://www.earthgauge.net/wp-content/uploads/2009/04/ace-basin-nerr_interior-wetlands_sc_noaa.jpg
Nurseries: Coastal near-shore wetlands
serve as important nurseries for fish, crab,
and other shellfish. This directly impacts
commercial fishing, a huge industry in the
United States.
http://farm4.static.flickr.com/3052/2766459005_284d6951fd_o.jpg
Wood Turtle
Wildlife Habitat: They are home to many
different kinds of animals.
Muskrat
http://www.on.ec.gc.ca/wildlife/factsheets/fs_coastal_wetlands-e.html#peopleneedwetlands
Wood Ducks
Storm surge buffers: Coastal wetlands
knock down the storm surge which
accompanies a hurricane and lessen the
strength of hurricanes before the hit
populated areas.
http://soundwaves.usgs.gov/2005/09/H_Dennisfig3LG.jpg
Erosion control: Barrier island marshes limit
shoreline erosion and stabilize seashores.
http://www.uvm.edu/~jbartlet/nr260/wetland%20formation/barrierisland.jpg
Recreation: Coastal wetlands also provide a
place for hiking, hunting, fishing, and birdwatching.
http://www.psdn.org.ph/wetlands/wetgraphics/importance_7.jpg
http://farm4.static.flickr.com/3188/2694554943_2f919e83f3.jpg
http://www.monmouthcountyparks.com/AgencyImages/130/fishing_turkey.jg
New Orleans: City at Risk
http://scrapetv.com/News/News%20Pages/usa/images-2/hurricane-katrina-superdome.jpg
How could one of the largest and
most important coastal cities in the
U.S. get destroyed by a hurricane?
http://www.fema.gov/hazard/hurricane/2005katrina/slideshow/photos/15507.jpg
The pink areas are built
below sea level. And why is that?
http://upload.wikimedia.org/wikipedia/en/3/32/Msyelevst.jpg
The French built New Orleans on the high
banks of the Mississippi River. (1726)
justeastofeden.blogharbor.com
The first
area settled
was called
the “French
Quarter.” It
was built on
high ground
by the
Mississippi
River.
http://www.chesnes.com/pics/urban_neworleans03/a29_small.jpg
http://soa.utexas.edu/news/archive/030107/images/FOAneworleans.jpg
Jackson Square
http://wpcontent.answers.com/wikipedia/commons/thumb/d/d8/StLouisCathedralJacksonStatue.jpg/180px-StLouisCathedralJacksonStatue.jpg
1798
http://www.lib.utexas.edu/maps/historical/new_orleans_1798.jpg
Swamps and marshlands were left
empty in early New Orleans.
http://whitechapelghoststyle.files.wordpress.com/2009/10/map-of-new-orleans-1849.jpg
In 1803, New Orleans became part
of the U.S. through the Louisiana
Purchase.
enchantedlearning.com
Even 150 years after the city started, the
marshes and swamps were mostly empty.
(1878)
http://farm3.static.flickr.com/2746/4016323355_e78049ae07.jpg
In the
late
1890s,
canals
were
dug to
partially
drain the
swamps.
www.journalofamericanhistory.org
http://lib.utexas.edu/maps/world_cities/new_orleans.jpg
Through a
system of
drainage
canals and
levees, the
swamps
were turned
into dry
land and
the city
grew.
But the only thing keeping the city from
drowning was the levee system.
http://www.classicalvalues.com/New-Orleans-Ground-Elevs.jpg
And the levees could not stand up to
the storm surge of Katrina.
National Geographic
Time.com
satellite images of
New Orleans
After Katrina
looked like
this
Before had
looked like
this.
http://geology.com/news/images/hurricane-katrina-flooding.jpg
So, 100+ years of building on former
swamplands – and not being able to
adequately protect
them – led to much
of the deadly
flooding.
http://www.katrinahelp.com/hurricane-katrina-pictures.html
GEOGRAPHIC LESSON:
STOP DESTROYING the natural
“buffer zone” between the ocean and
the occupied land.
http://habeasindex.org/wp-content/uploads/2008/09/lead095il.gif
Louisiana originally had miles and miles
of coastal marshes. These came from
the Mississippi River’s delta as the river
deposited
rich silt at
the mouth
of the
river.
http://rlv.zcache.com/mississippi_river_delta_satellite_postcard-p239580941934606112qibm_400.jpg
Hurricanes gain energy from the heat of
warm water in the Gulf of Mexico. So
when a hurricane travels over the
marshlands, it loses some energy
BEFORE it hits populated areas.
http://www.magazine.noaa.gov/stories/images/laraineyrefugemarsh.jpg
Scientists sometimes refer to coastal
mashes as “nature’s speed bumps” for
hurricanes.
http://farm1.static.flickr.com/34/122926506_15d85e7381.jpg
http://4.bp.blogspot.com/_axeScVj_ges/SrfHbVn1SbI/AAAAAAAAASY/l84ftH3rOak/s320/Speed_Bump.jpg
Scientists also tell us that for every 3
miles of marshland, a hurricane’s
storm surge is knocked down by 1 foot
-- before it hits populated areas.
http://www.co.baldwin.al.us/Uploads/Images/Surge.bmp
But humans have been draining the
marshes over the past many years.
That turns marshes into solid land,
and people move in.
http://www.cclockwood.com/stockimages/saltmarsh.htm
And canals they built further erode
the marshlands. Old marshes are
turning into open ocean.
http://www.cclockwood.com/stockimages/coastalerosion.htm
Concrete levee systems also prevent
silt from naturally rebuilding the delta.
Louisiana is losing 25 square miles a year of marshlands.
http://earthobservatory.nasa.gov/images/imagerecords/15000/15425/MissDelta_TMO_2005221_lrg.jpg
Rock jetties are now used in some
places to slow marshland erosion.
http://www.cclockwood.com/stockimages/EN-MARSHRESTORE-1072.jpg
And the U.S. Corps of Engineers
has actually built pumping sites to
pump silt-filled Mississippi water
over the levees & into the marshes.
http://www.mvn.usace.army.mil/pao/dpond/davispond.htm
Protecting – and rebuilding –
coastal wetlands will help us with
water quality, erosion control, and
protection against hurricanes.