Coral Reefs

Coral Reefs

Coral Reefs

• Warm shallow ,tropical waters

• Limestone ridges built by tiny coral animals,• coral polyps with the

algae that live inside.

http://flowergarden.noaa.gov/image_library/coral/polypcloseup.jpg

•Zooxanthellae is an algae that live inside coral and share a symbiotic relationship with them.

•Zooxanthellae provide oxygen and other nutrients to the coral polyps and the polyps give the algae the carbon dioxide they need to survive.

Zooxanthellae also give coral its beautiful color. Without Zooxanthellae, Coral have clear bodies and white skeletons.

• Polyps secrete skeletons of limestone• Outer layer only contains living animals

Shrinking a CO2 Sink:

•Coral polyps use Carbon Dioxide to form their shells. This helps decrease the amount of carbon dioxide in the ocean and is one way the Earth combats pollution and works to regain homeostasis. •With less coral, the ocean absorbs

less Carbon Dioxide, leaving more in the atmosphere

Killing the Hope for a Cure:•Coral reefs are probable sources of medicines

to cure the diseases•Chemicals found in the reefs have been used

to treat ulcers, heart disease, leukemia, and more. In one of the most famous instances, AZT, which is based on chemicals extracted from a Caribbean reef sponge, has been used to treat HIV infections. • Currently, more than half of all cancer

research is focused on finding cures from marine sources. Every time a reef is destroyed, the chance of relieving the pain and suffering of people all over the world is reduced.

The Loss of Natural Coastal Protection:

•Reefs form near the shores of low lying coastal lands. They are a natural barrier of protection against currents, strong waves, and storms. •Without the reefs to slow the water before it

reaches the shore, these areas are very vulnerable. •In one area where a reef was destroyed, it cost

about $10 million per kilometer to build a protective wall along the coastline.

The Demise of Economies Dependent on Reefs:

•Many humans are dependent on Coral Reefs for their livelihood. •It is estimated that reef fish and mollusks feed

between thirty and forty million people each year. •Also, beautiful and exotic reef fish can also be

sold as pets, providing cash income to families in poverty stricken areas. •Tourism provides the basis for entire

economies in many regions. With responsible treatment of the reefs, it would be possible to sustain the lives of people who have close relationships with the reefs.

The End of Habitats with a High Density of Biodiversity:

•Coral reefs are truly the rainforests of the sea. •They cover only about 1% of the ocean floor,

yet are home to about 25% of all marine life- approximately 35,000 to 60,000 different types of organisms. They are beautiful, lush,

habitats brimming with natural resources.

Pollution: •Water Contamination•Oil spills, waste dumping, and other

byproducts of human advances have resulted in the contamination of the oceans. When the homoeostasis of the reef area is lost, there is an overgrowth of algae. When too much algae grows on the reef, the

coral cannot get enough oxygen and is the reef is effectively smothered by Nitrogen and Carbon Dioxide.

Pollution: Increased CO2•Increases in the amounts of carbon dioxide

found in water have had an adverse effect on coral. •The Carbon Dioxide seems to be dissolving the coral skeletons and making them much

weaker. •The process has been compared to

osteoporosis in humans, and is leaving the fragile coral

structures weak and even more vulnerable to

anthropogenic fluxes.

Pollution: Global Warming and Ozone Depletion

•Global warming has translated into oceanic warming, the rising temperature of earth’s oceans. •This process, combined with the depletion of earth’s ozone and subsequent increases in ultraviolet radiation, has lead to what is known

as “coral bleaching”. Coral bleaching occurs when the coral polyps, stressed by changes in temperature or UV radiation, expel the zooxanthellae which are necessary for their survival. This not only “bleaches” them and causes them to lose their color, it often leads to their death.

Direct Contact: Tourist Economies

•Tourism has caused severe damage to the reefs. •Corals are often removed from their habitat to be sold

as souvenirs. •in some coastal areas with rapidly growing

populations and development, piers and docks have been built right on

top of coral reefs. •Careless divers often inadvertently destroy coral reefs

by kicking them or dropping anchors from their boats directly onto the coral.

•In poorer countries, septic waste from resorts often leaks out into the ocean, killing off the fragile corals.

Direct Contact: Fishing

•Humans destroy coral reefs directly through unfriendly fishing habits. Many coral reefs are overfished, destroying their sustainability.

practices like cyanide fishing and blast fishing destroy reefs. Cyanide fishing is a method in which divers squirt cyanide into reef crevices and onto fish, stunning them and making

them easy to catch. Small organisms, especially coral polyps, are killed by the cyanide in this process. Blast fishing, in which explosives or gun shots are sent into the reefs, can completely destroy the reef structure.