What are Living Shorelines

1
What are Living Shorelines? by Dr. Chris
Boyd Mississippi State University Mississippi
Alabama Sea Grant Consortium cboyd_at_ext.msstate.edu
Tom Cathcart
NOAA Restoration Center
2
Why Do you live on the Coast?
3
View of the coast Walk out on a beach Put your
feet into the water Fishing, crabbing,
etc. Climate, cool breeze Serenity Surfing Boating
Fresh Seafood
4
Gulf of Mexico ? Contains some of the most
diverse flora and fauna in the world ? Accounts
for one-third of the coterminous U.S. coastline
and drains 41 of the continental U.S. (Turner,
2003) ? Tourism and recreation comprises 70 of
employment in the ocean economy in the GOM
region (Colgan 2006) ? Population growth has
increased 21.6 between 1990 and 2004 ? 55
percent of the U.S. population lives within 50
miles of a coast.
5
Why should we use natural shoreline structures
rather than Seawalls or Bulkheads? ? Seawalls
cause erosion to adjacent structures ? Reflect
Wave energy ? Decrease amount of organic matter
and biological organisms needed for maintenance
of wetlands ? Loss of inter-tidal habitat ?
Seawalls need maintenance after storms and are
not a permanent solution ? Loss of sandy beach
? Vertical erosion in front of seawall
USGS
Mark S. Peterson
Wisconsin Sea Grant
6
Shoreline Armoring Statistics and Trends 30 of
Mobile Bay has been armored as of 1997 using
rip-rap, seawalls, and bulkheads (Douglass and
Pickel) gt 75 in some heavily populated Counties
in California 18 miles/year permitted in
Virginia since 1994, 230 miles 1993 2004 45
of Floridas developed east shore 50 of Florida
developed west shore gt 50 of South River in
Maryland has been armored San Diego Bay is 74
armored
7
population
of shoreline armored
Douglass, S. L.
Rate of increase in armoring similar to increase
in population
8
Progression of the Typical Response to Bay
Erosion time t1
At time t1, the home is located on a receding
shoreline.
Douglass, S. L.
9
Progression of the Typical Response to Bay
Erosion time t2
At time t2, the homeowner constructs a bulkhead
to protect the upland property.
Douglass, S. L.
10
Progression of the Typical Response to Bay
Erosion time t3
At time t3, the homeowners bulkhead begins to
interfere with the nearshore coastal processes.
Douglass, S. L.
11
Progression of the Typical Response to Bay
Erosion Time t4
At time t4, profile lowering occurs in front of
the bulkhead leading to the loss of intertidal
habitat.
Douglass, S. L.
12
Progression of the Typical Response to Bay Erosion
Loss of intertidal area due to passive erosion
Douglass, S. L.
13
Example shoreline on eastern shore of Mobile Bay
(circa 1996)
Note barnacles on wooden bulkhead Tide range
here is 1-2 feet.
6 feet
4 feet
2 feet
Bathtub!
Douglass, S. L.
14
We need to work together to maintain a
sustainable coastal environment due to ?
Increased population growth in coastal region ?
Increased risk of water quality problems ? Loss
of beaches ? Loss of public beach access ? Loss
of wetlands ? Once beaches and sediment are lost
to rebuild is enormous ? 80 of
Florida residents live within 10 miles of the
coast
15
What factors create erosion? ? Wind velocity ?
Wave energy and duration ? Fetch of water that
generates waves, distance that waves can be
generated by winds ? Fetch ? Wave Climate
Sand Transport ? Width and shape of beach ?
Boat wakes ? Storm water runoff ? Unprotected
land on property ? Lack of sediment for
longshore transport
Groins, North Carolina Division of Coastal
Management
Cathcart, T., Melby, P., and Pote, J.
Cathcart, T., Melby, P., and Pote, J.
Cathcart, T., Melby, P., and Pote, J.
16
What are the problems associated with Coastal
Erosion? ? Causes loss of residential and
commercial property ? loss of storm buffering
capacity ? Soil loss ? Increased suspended
solids ? Water Quality degradation
Erosion of the Gulf shore eventually destroyed
this beach house at Captiva Island, Florida. USGS
Wisconsin Sea Grant
17
Benefits of Erosion Erosion is essential for
productive bays, estuaries, salt marshes, and
tidal flats. Before the littoral drift system
was altered, sand was naturally bypassed around
tidal inlets and shared between neighboring
coastal segments
Photo NOAA
Photo NOAA
18
Structural Techniques/Shoreline Hardening
? Use man-made structures to alter the patterns
of erosion and deposition of sediment. ? Goal
is to reduce erosion in one location ? Potential
problem is that it can cause erosion elsewhere in
the watershed and reduce essential aquatic
habitat ? Private landowners see an immediate
erosion protection product
MASGC
MASGC
MASGC
19

• What are the alternatives to hard structures such
  as Seawalls, Bulkheads, and Rip-rap? Living
  Shorelines
• Do nothing. Set back your house from the edge of
  the river, bay, or beach
• Plant vegetative cover such as seagrasses and
  submerged aquatic vegetation
• Soft, non structural stabilization
• 4. Offshore breakwaters
• 5. Hybrid Structures
• 6. Bulkheads, seawalls, rip-rap

20
What are living shorelines? Shoreline
stabilization using living plant material
(emergent and submerged aquatic vegetation),
oyster shells, earthen material or a combination
of natural structures with rip rap or offshore
breakwaters to protect your property against
erosion. Living shorelines provide a more natural
approach for erosion control, while allowing
access for coastal and estuarine organisms
Miller, D.
S. L. Douglass
NOAA Restoration Center
21
What are the benefits of Living Shorelines? ?
Maintain natural coastal processes ? Create or
preserve habitat ? Preserves access for aquatic
and terrestrial organisms ? Maintains land to
water access for property owners ? Improves
water quality ? Economical
NOAA Restoration Center
NOAA Restoration Center
MASGC
22
Type of Erosion Control Vegetative Cover Wetland
Plants Smooth Cordgrass Saltmeadow
Cordgrass Mangroves Dune Plants Sea
Oats Panic Grass Maintenance remove
debris, prune trees, fertilize, make sure to keep
people out of the protected area as much as
possible
University of Florida pub Eny-660
Gary Fine, USDA-NRCS, 2000
Plantmaterials.nrcs.usda.gov
Pass Christian, MS, HCSWCD/NRCS
http//www.ms.nrcs.usda.gov/technical/MS_Coast_Pla
nts_Guide_Poster_07.pdf
23
Type of Erosion Control Soft, non-structural
stabilization Erosion Control Blankets Straw
Blanket Coconut Straw Blend Coconut
fiber Non-woven geotextiles Other
products that could be used beach nourishment,
geotubes, coir logs, bioengineering,
etc. Maintenance Straw and coconut fabrics are
biodegradable and are used to aid with growth of
new vegetation. Geotextiles have very long life
span but are UV sensitive
http//www.arlingtonecho.net/Restoration-Projects/
Shoreline-Restoration.html
Biolog, NOAA Restoration Center
Beach nourishment project near Gulf Shores, AL.
USGS
24
Type of Erosion Control Shoreline
revetment Riprap Articulating Concrete
mat Maintenance typically very little,
might have to add some new rock overtime
Rookery Bay National Estuarine Research Reserve
Mangrove Restoration Project
NOAA
Bernard Bayou, Gulfport, MS
25
Type of Erosion Control Offshore
Breakwater Oyster Shell Oyster Shell
bag Concrete Reef Balls Wave
Attenuation Device Limestone
breakwater Rock Breakwater Wooden
Sills Maintenance addition of oyster
shell or rock over time. Wooden sill will need
to be inspected routinely.
Spencer Rogers, North Carolina Sea Grant
NOAA
LaDon Swann, Mississippi-Alabama Sea Grant
Consortium, Auburn University
26
Hybrid Structures ? Soil Stabilization method
that combines hard structures with more
natural materials ? Ex. Marsh fringe with
groins, Marsh fringe w/ wooden sills or rock
breakwaters, Beach nourishment with
breakwater ? Used to restore, protect and create
habitat Maintenance addition of oyster shell or
rock over time, inspect wooden sill, remove
debris, prune trees, fertilize, make sure to keep
people out of the protected area as much as
possible.
http//www.arlingtonecho.net/Restoration-Projects/
Shoreline-Restoration.html
S. L. Douglass Dog River,
Mobile, AL
Rock sill with marsh restoration NOAA Ocean and
Coastal Resource Management
27
Type of Erosion Control Bulkheads Vinyl Vin
yl w/ toe protection Wooden Wooden w/ toe
protection Maintenance scour typically
occurs, so toe protection might be needed,
additional fill and vegetation will need to be
installed over time
MASGC
MASGC
MASGC
MASGC
28

• The Following Steps Should be Taken to Determine
• the Proper Erosion Control Alternative
• Conduct site assessment (includes bank erosion
  rate, bank elevation, bathymetry, fetch, wave
  energy, prevailing wind direction, vegetation
  presence, and soil type)
• Project Design
• Cost estimate
• Apply and receive permit
• Hire Contractor
• Construct project

29
What do we need to do to promote and make
alternative shoreline erosion structures
successful? ? Determine appropriate sites ?
Make products available and advertise ? Promote
growing and planting native vegetation ex. Sea
oats, smooth cordgrass, saltmeadow cordgrass,
panic grass. ? Create design alternatives ?
Low maintenance yards ? Educate homeowners and
contractors ? Incentives (tax breaks, possible
grants)
Florida Sea Grant
HCSWCD
30
References Broome, S.W., S.M. Rogers Jr., and
E.D. Seneca. Shoreline erosion control using
marsh vegetation and low-cost structures. Sea
Grant publication UNC-SG-92-12. http//www.ncseagr
ant.org/index.cfm?fuseactionproduct_browse_catego
rycategoryCoastal20Hazards Douglass, S. L.
and B. H. Pickel. 1999. Headland Beach
Construction on Bay Shorelines. Proc. 1999
National Conference on Beach Preservation
Technology, FSBPA, Tallahassee, FL. Douglass,
S.L. and Pickel, B.H. 1999. The Tide Doesnt Go
out Anymore the Effect of Bulkheads on Urban
Bay Shorelines. Shore and Beach
67(23)19-25. Hardaway, C.S. R.J. Byrne. 1999.
Shoreline Management in Chesapeake Bay . Virginia
Institute of Marine Science, Virginia Sea Grant
Publication VSG-99-11. http//nsgl.gso.uri.edu/vsg
cp/vsgcpg99003.pdf Morton, R. A., T. L. Miller,
and L. J. Moore. National Assessment of
Shoreline Change Part 1 Historical Shoreline
Changes and Associated Coastal Land Loss along
the U.S. Gulf of Mexico. 2004. U. S. Geological
Survey Open-file Report 2004-1043, 45p. Living on
the Coast Protecting Investments in Shore
Property on the Great Lakes. 2003. U.S. Army
Corps of Engineers and University of Wisconsin.
http//seagrant.gso.uri.edu/factsheets/fserosion.
html http//www.habitat.noaa.gov/restorationtechni
ques/public/shoreline_tab1.cfm http//www.masgc.o
rg/mini/livingshorelines.htm