Vegetated sand ridges called dunes, built up by
dry beach sand blown inland and trapped by plants and other obstructions, back
most beaches. As sand accumulates, the dunes become higher and wider.
Plants play a vital role in this process, acting as a windbreak and trapping
the deposited sand particles. A characteristic of these plants is their ability
to grow up through the sand and continually produce new stems and roots as more
sand is trapped and the dune grows.
Stable sand dunes play an important part in protecting the coastline. They act
as a buffer against wave damage during storms, protecting the land behind from
salt-water intrusion. This sand barrier allows the development of more complex
plant communities in areas protected from salt-water inundation, sea spray and
strong winds. The dunes also act as a reservoir of sand, to replenish and
maintain the beach at times of erosion.
Frontal sand dunes are vulnerable. The vegetation can be destroyed by natural
causes such as storms, cyclones, droughts or fire, or by human interference
such as clearing, grazing, vehicles or excessive foot traffic. If the
vegetation cover is damaged strong winds may cause 'blowouts' or gaps in the
dune ridge. Unless repaired, these increase in size, the whole dune system sometimes-migrating
inland covering everything in its path. Meanwhile, with a diminished reservoir
of sand, erosion of the beach may lead to coastal recession.
To avoid this, protecting the vegetation is vital. The beach, between high and
low tides, is hard-wearing but the sensitive dunes, which we cross to reach it,
must be protected also. For this reason damaged and sensitive dunes might need
to be fenced and access tracks for vehicles and people provided.
Processes such as waves, near shore currents and tides continually modify
shorelines. The ability of beaches to maintain themselves is achieved through
these natural forces. The natural process of beach renourishment, sometimes
called "dynamic equilibrium", is how the beach responds to weather.
When waves are high during storms or when hurricanes hit the shore, sand is
carried from the beach and deposited on the ocean floor. This makes the ocean
bottom flatter and makes waves break further from shore and smaller. During
subtle weather or erosion, smaller waves slowly shift the sand back to the
shore and replenish the beach.
When people build homes or resorts on beaches, the buildings interrupt this
natural process because the sand that is usually taken by storms is removed so
that humans may build. When erosion catches up with them they scream for help
and defense against the angry sea.
Hard structures, like bulkheads, seawalls and groins, are built on beaches to
prevent erosion, but they usually backfire. In the long run after a beach has
been "defended" by a hard structure, the beach will have been carried
out to sea while the homes still stand.
Bulkheads and seawalls protect banks and bluffs by completely separating land
from water. Bulkheads act as retaining walls, keeping the earth or sand behind
them from crumbling or slumping. Seawalls are primarily used to resist wave
action. Design considerations for these types of structures are very similar.
However, these structures do not protect the shore in front of them. In fact,
when bulkheads and seawalls are used in areas where there is significant wave
action, they may actually accelerate beach erosion. This happens because much
of the energy of the waves breaking on the structure is redirected downward, to
the toe where the wall meets the soft sand or earth. The shore on this side of
the bulkhead or seawall is thus subjected too much more of the force of the
waves than if there were no wall, and it erodes quickly. Man made structures
interrupt wave-driven drift, stealing sand from down shore beaches.
In the US, many coastal states, including South Carolina, Georgia and
California, have passed laws preventing the destruction of beach dunes. These
laws state that people cannot build houses on the dunes. Boardwalks and other
structures that allow people to reach the beach must be approved and be
constructed in a way so as to not interfere with the preservations of
surrounding dunes. Furthermore, it is illegal to "pick" or otherwise
remove vegetation such as sea oats, which help maintain the dunes.
Most people who visit the beaches annually are quite impressed by the beauty of
the sea oats growing on the primary dunes along the oceanfront. But this hearty
grass performs a far more important function than adding its good looks to the
scenery. It helps to hold the sand and protect the dunes from wind and erosion.
Since sand dunes are so dry, a 6-inch sea oats plant may have roots, which are
five feet long. This long root system helps stabilize the dunes against
erosion. In addition, the plant above ground can catch windblown sand to
increase the size of the dune.
The sea oats are important that Florida law prohibits the picking of them at
any time. Driving on the dunes is also prohibited. Also, people are urged to
use boardwalks when walking over the dunes in an effort to preserve the
beach-protecting sea oats.
Many scientists use the term “newjerseyization” when referring to the
destruction of beaches by hard solutions because New Jersey was one of the
first states to start extensive armoring of its coastline. New Jersey has seen
about half of its beaches disappear because of human error, and just
overlooking the problem.
Instead of understanding the nature of the sea, we turn to help from the
government and tax money to bail us out. There currently exist about fifty
government-funded programs that range from building coastal highways to the
massive rebuilding of sandy beaches and costly installation of man-made
seawalls. These programs cost millions and only benefit the owners of the
coastline property, while the taxpayers get stuck with the bill. Many states
have banned open-ocean seawalls, finally realizing the irreversible damage that
they do to beaches.
Beach renourishment, to replenish the beaches with more sand, is the most
environmentally sound because it causes no real harm in the long run. The cost
however, is incredible, and the results are short term. In most cases,
replenished beaches must be redone on a regular basis, usually every few years.
In New Jersey for example, the government has already spent almost $100 million
to dredge sand from the ocean floor and dump it onto 33 miles of coastline.
Ocean City Beach was renourished in 1982 for five million dollars, but washed
away in only two and a half months.
When beach residents demand something be done about the beach dune erosion, and
all the money the is spent on contemptible endeavors to stop mother nature, a
storm or hurricane will come along and wipe out the development. Then billions
of dollars are spent to rebuild coastline homes and resorts, which set up a
repeating cycle of economic and environmental idiocracy.
One day, in a better society, we will save our beaches from development so that
everyone is free to enjoy them in an unhampered, natural state. We will stop
wasting billions of dollars in our futile attempts at man-made beach
resurrection and pointless rebuilding of homes and resorts. It will become
clear that the development of America's coastline is too costly to maintain and
is destroying our beaches. Until then we will scurry to the tiny public
designated beach access areas, fight for parking spaces and sunbathing
positions, and enjoy one of our planet's most beautiful assets while we can.