Coral Reef
cause and effect
Evelyn H. Hartvigsen
http://ehartvi1.wordpress.com/
Coral Reef, a living building block just under the oceans surface. Coral, by
definition is “the hard, variously colored, calcareous skeleton secreted by certain marine
polyps” (Dictionary.com). A reef is “a strip or ridge of rocks, sand, or coral that rise to or
near the surface of a body of water” (Dictionary.com) together you have a living colony
taking care of itself and other species.
Coral Reefs are a benefit in many ways. It is a living organism, an animal, which
supports thousands of other organisms. Many species live on or in a coral reef, using it as
a home and for nutrients. Coral Reefs are not only life sustaining for species living in the
sea but outside of it as well. A healthy coral reef can be a great tourist attraction due to
their interesting shapes and beautifully colored polyps. Polyps are the individual coral,
which are themselves ancient animals related to jellyfish (Basic Facts About Coral
Reefs/Defenders of Wildlife). Fishing in these areas is also an activity that local humans
survive off of. They use it not only to feed themselves, but for tourist fishing and a
worldwide demand of fresh fish. Thereby bringing financial support to the area. However
the lasting effects caused by the over use of both of these activities are only a drop in the
bucket of the problematic situations the world’s coral reef populations face.
Over fishing an area not only
depletes the species of fish, but also takes
away the grazers who would help keep
algae at a low level. Populations of
grazing fish eat the algae that grow on the
coral reef, which then enables the coral to
Figure 1 Healthy coral vs. Bleached coral
thrive and not be over grown. (National Center for Ecological Analysis and Synthesis).
And too much human interaction in any natural environment can cause issues. Sometimes
these issues are caused by accident
such as: coral damage and/or contamination of an area.
Another challenge to the survival of a coral reef is bleaching (Figure 1), “while
episodic, it is a major contributor to coral loss” (Ledlie et al., 2007; Mumby, 2009b).
Bleaching is a response to stress, or change in environment. The coral dies and loses its
color, turning white. It is hard to define the exact causes of this reaction due to several
overlapping factors, but temperature change is a large contributor. There have also been
cases of Solar Irradiance, which is a bleaching due to seasonal temperature change. A
change in tide patterns, such as a low tide, can leave a once covered coral reef exposed to
more sunlight and heat linking it to the bleaching effect. This occurrence is called a subaerial exposure. There has been a very noticeable amount of bleaching taking place since
the 1980’s, be it human caused or natures way of adapting and evolving it has taken its
toll on the reefs around the world.
Coral Reefs also face freshwater dilution; this takes place during times of severe
weather. With large gusts of wind causing displacement of the ocean water, and large
amounts of fresh rainwater taking its place, the chemical make up of the ocean water
changes and causes the biological makeup of the coral to become unstable. Instability can
create an atmosphere for disease and the corrosion or death of the coral and all the life
that survive with it.
Some say that global warming is responsible for many of the environmental woes
of the modern day. There are studies detailing that mankind’s way of life has had
devastating effects on the climate around us. Not everyone agrees, so more and more
studies are done, not only to understand but also to inform and hopefully enlighten us.
What is the best way to deal with, or stop this deterioration, is there a way? One such
study shows that deforestation is a huge influence in the changes we are seeing in the
ocean. In historical records signs of the decay of the coral reefs in the Caribbean are
shown in the beginning of the 1900s. This was during the time period that many coastal
areas were being cleared for plantations. The belief being that less trees equals more
carbon dioxide in the air. The ocean absorbs the carbon dioxide like a sponge, which has
been good for the surface above the ocean; it has helped reduce greenhouse gas levels in
the atmosphere. This change however has greatly affected all life in the ocean; the sizes
of species like oysters and clams have shrunk. Different types of coral, once dominant,
have become recessive. Branching coral has shifted to non-branching coral, there by not
able to spread out and increase its volume (Ecology Letters, journal and research funded
by the National Science Foundation the Smithsonian Institution, the Center for Marine
Biodiversity and Conservations at Scripps). The higher amounts of carbon dioxide in
ocean water, the lower the potassium hydrogen level. This decrease in seawater pH
wreaks havoc with the ability of sea life to form correctly; organisms are unable to
develop their shell, which has been called “ocean acidification” (Coral Reef Alliance;
Threats to coral reefs).
A second side effect of deforestation is the pollutants that are discarded in the
ocean. When land is cleared along a coast line the debris has to go somewhere, at times
the left over, torn up earth including dirt, trees, rocks, sticks, all end up in the ocean. This
action causes stress on the life forms surviving below the surface of the water, again
adding to an already stressed situation.
The damage that is done in the beginning by overfishing, polluting the
environment, dumping, cutting, basically pillaging and plundering, comes full circle.
Less coral reefs equal less marine life, which in turn affects tourism, financial stability,
food supply, species survival, and the fragile state that the earth is already in. The damage
that has been done cannot be reversed, but it can be slowed. Changes in laws, controlling
pollution, better kept fishing habits, planting trees, all steps to adapt to our always
evolving world. Coral reefs make up less than 1% of marine environment but they are
home to 25% of the ocean’s marine life, that is a lot to take care of in a small space. Any
damage at all is not acceptable, even the smallest amount of change can end a species,
and/or a way of life. If this much damage is apparent through historical data and study,
how much more damage or proof will there have to be before something is done to stop
it?
References
Cover http://www.theguardian.com/environment/2011/feb/23/coral-reef-report-dying-danger
Figure 1 - http://sunscreenpollution.blogspot.com/2013/04/what-is-issue-in-2013-americancancer.html
Figure 2 -http://www.theguardian.com/environment/2011/feb/23/coral-reef-report-dyingdanger
Coral Reef Alliance
Defenders of Wildlife
Ecological Modelling: journal –Carlos Ruiz Sebastian a,b, * Timothy R. McClanahan a – Ledlie
et al., 2007, Mumby, 2009b
National Science Foundation, the Smithsonian Institution, the Center for Marine Biodiversity and
Conservation at Scripps
National Center for Ecological Analysis and Synthesis
University of Miami Rosenstiel School of Maine & Atomospheric Science (2011, May 30)