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.

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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

Wildlife Habitat: They are home to many different kinds of animals.

http://www.on.ec.gc.ca/wildlife/factsheets/fs_coastal_wetlands-e.html#peopleneedwetlandsMuskrat Wood Ducks

Wood Turtle

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 bird-

watching.

http://www.psdn.org.ph/wetlands/wetgraphics/importance_7.jpg

http://www.monmouthcountyparks.com/AgencyImages/130/fishing_turkey.jg

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New Orleans: City at Risk

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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?

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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)

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In the late 1890s, canals were dug to partially drain the swamps.

www.journalofamericanhistory.org

Through a system of drainage

canals and levees, the

swamps were turned

into dry land and the city grew.

http://lib.utexas.edu/maps/world_cities/new_orleans.jpg

But the only thing keeping the city from drowning was the levee system.

http://www.classicalvalues.com/New-Orleans-Ground-Elevs.jpg

National Geographic

And the levees could not stand up to the storm surge of Katrina.

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

deposited

rich silt at the mouth of the river.

Louisiana originally had miles and miles of coastal marshes. These came from the Mississippi River’s delta as 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://4.bp.blogspot.com/_axeScVj_ges/SrfHbVn1SbI/AAAAAAAAASY/l84ftH3rOak/s320/Speed_Bump.jpghttp://farm1.static.flickr.com/34/122926506_15d85e7381.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.