The Alien Song--Interesting! (Quicktime movie)
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Reefs themselves are one of the most interesting environments on earth. As the corals grow, they add on layer upon layer of carbonate rock. As a reef ages, it can create enormous packages of limestone. Reefs are one of the few places in the world where living things change the face of the geology to such an extreme degree, as they can create islands and add on to continents.
The corals are actually a symbiotic relationship between to very different organisms. The symbiosis is between photosynthetic algae and an animal known as a polyp. The polyp itself is a simple organism that belongs to the Animal phylum and is closely related to jellyfishes and sea anemones. However, it is the photosynthetic algae allow the reefs to function. They act as part of the producers for the food web, making coral the foundation of which all other organisms in the ecosystem obtain energy.
Because they are the foundation of their environment, it is essential that reefs stay healthy. They provide a home for thousands of different species of fish, jellies, sharks, snakes, sea stars, and countless other types of living things. Moreover, because there are so many different types of species, they have evolved to be highly specialized. Often these species are so highly adapted to a specific environment that they are not found anywhere else in the world. This only further underlines the importance of coral reefs, as soon many other living things rely on a very fragile set of conditions that allow the coral to exist.
However, human activity has severely damaged the reefs. Across the world communities are reporting that many coral ecosystems are dying off. In a Dalhousie University study between 1999 and 2001 showed that coral ecosystems living around or near areas of large human populations were significantly less healthy then those who away from industrialized settlements. While this threatens many different kinds of corals, there is a greater problem at hand. Because the corals are major producers on the reefs, taking them away would cause the entire ecosystem to collapse. While it would take away habitats for many other species, but it would also sever the best way for the sunÕs energy into the system.
The question remains what are humans doing that is damaging the reefs to the point of collapse. There are three main reasons why coral reefs are in danger because of industrialized civilization. The first is global climate change. This damages these special environments in several ways.
Rising sea levels is causing once shallow areas to become deeper. This limits the amount of sunlight that gets to the photosynthetic algae that live in symbiosis with the coral polyp. The sun is of course the source of all energy on earth and living things cannot exist without it. The rise in sea level can also subject the reefs communities to wave frequencies that the animals and plants have not adapted to.
However perhaps the factor that is most threatening factor of the increase in global climate change is its cause. Around the world carbon dioxide levels are rising, and are causing weather patters across the planet to change. While it can bring warmer winters to areas such as Ohio, if sustained it could potentially change the climates widespread areas. While this could cause some current areas to dry out, it could also cause other areas to receive more precipitation. This could cause current rivers to become bigger or create completely new fluvial systems, which would result in an increased sediment load in clear waters. Clear waters are essential for coral reefs to exist, as they need the sunlight in order to produce energy.
Rising carbon dioxide levels would also cause another complication. With more carbon dioxide molecules in the air, more then exist in the water. An increase of carbon dioxide molecules in the water would make it difficult for the coral polyps to build their carbonate homes. The water would be saturated and it would make it more difficult for the coral to make the calcium carbonate to precipitate in the water. This would significantly hamper their ability to build their homes and would slow down the growth of new reefs.
Another concerning issue that is hurting coral ecosystems is agricultural runoff. This problem is also seen in lakes, were eutrophication is causing freshwater environments to age faster then they should. Nitrogen from agricultural fertilizer gets washed away after over use by farmers. This increase in nutrients flows into the groundwater system and eventually are washed to the sea. Here they accumulate and give phytoplankton and other forms of algae an abnormal level of resources and allows the water to support more individuals then normal. This causes what is called algal bloom and it has two adverse effects on coral reefs. The over load of algae blocks out the sun which chokes off the photosynthetic corals and consequently, their source of energy. This of course hurts the rest of the ecosystem, as they have no way to obtain energy themselves. The second way that algal bloom hurts the reefs is that when the seasons change and the run off is no longer giving a ready supply of nitrogen to the area, the algae dies. All of the algae dying accumulate on the floor of the ocean, which is where the reefs live. This covers the reefs and again blocks off the sun.
The last big way in which human activity is hurting the coral reefs is fish farming. These farms are stocked with large amounts of staple foods for people. While this is an effective way of growing food cheaply, it introduces species that are not native to the area. Because these invasive species have no natural predators other the people who raise them, they out compete the local fish. This causes a collapse in the food web, as some important species die out and other flourish unnaturally. These fish farms are also very dirty and require boats to maintain them. This puts pollution in the water in the form of chemicals and gasoline. It also churns up the water and propellers could potentially damage corals.
Coral reefs around the world are in danger. A recent study said that the worst case scenario for carbon dioxide levels rising is 500 ppm, which could easily be eclipsed in the next 50 years. This would cause so much damage to the reefs that half of the sea life would be extinct. Professor Terry Hughes, director of ARC Center of Excellence in Coral Reef Studies says that the window of opportunity to save the reefs that we still have is Òrapidly closingÓ. The question now is what, if anything, can be done about our disappearing reefs.
One of the best ways that reefs can be saved is education. While most people know that the environment is in danger, many do not realize that the reefs are rapidly disappearing and could be gone forever very soon. Aside from not even knowing that the reefs themselves are in trouble, it is also important to spread the word on why the are disappearing. If people know that fish farms are hurting coral reefs, they would be less inclined to buy fish from such sources. Currently many groups promote awareness of the peril of coral reefs. However, it is going to take widespread policy changes of governments. The United States, because it is such a prominent power and is in close proximity to one of the most famous reefs systems, should be the leader in taking care of them. It will not be easy as many changes need to take place. Higher mileage standards on automobiles, tighter restrains on carbon emissions, and a commitment to clean energy sources across the country such as nuclear power will all need to be implemented.
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