Coral Reef Depletion

By: Alea Dellecave

Section 1: Intro

Being residents of Florida I believe most of us have been snorkeling, or scuba diving before to see the coral reefs. The unde

rwater forests hold a sight of mystery and beauty. However, coral reefs have been diminishing all over the world. Scientific investigators don't know much ab

out the historical background of coral reefs bec

ause they didn't start to study them until the species began to degrade. The changing temperature is a main contributor to the death of most corals. it leads to many other unwanted causes. An unpublished analysis of the most recent survey date indicates that Pacific Coral Cover is roughly 30%, probably half of what it was several decades ago. The main contributors to coral loss is coral bleaching, coral diseases, and the most recently found factor ocean acidification.

Section 2: Discovery

The world's coral reefs are on a downward spiral. A study made in 2004 estimates that since the 1950s, 20% of all reefs worldwide have been destroyed, some with no hope of recovery. 22% of the Caribbean reefs were already dead as of 2002, with only 5%of Jamaica's reefs remaining. There are many causes of these rapid reef losses. Some of the causes are localized to reefs in certain countries or regions, while others are caused because of global threats.

The discovered threats leading to the death of most corals because of temperature change are:

• Coral Bleaching
• Coral Diseases
• Ocean Acidification
• Human Interference
• Pollution

Coral Bleaching:

Coral Bleaching is the process of coral when it goes from its original color to a dull white or gray. Coral bleaching occurs when the temperature of the ocean is changed drastically. A plant like organism thats lives within the corals tissues called zooanthellae, has been dieing as a result. The zooanthellae provide their coral host with food and oxygen, and in return they receive nutrients, carbon dioxide, and an enemy free shelter. When the summertime waters are just a degree or two higher is it critical. The relationship between the two breaks down. The zooanthellae leaves or dies, often leading to the corals death. The greater the magnitude of the warming, the greater effect on the oceans corals. This phenomenon is rightly called "coral bleaching" because the coral animal appears to turn white after the loss of it's zooanthellae.

• This here is an image of coral bleaching. The before picture has a healthy coloring; the white coral has been bleached.

Coral Diseases:

Ocean warming also indirectly kill corals by magnifying the effects of infectious diseases, which is another primary loss of the species. the number of diseases has been quickly increasing over the past 20-30 years. The severity of marin

e diseases could increase with temperature for several reasons. Because of the elevated water temperature it causes corals physiological stress and compromises their immune system, which can ultimately make them more prone to diseases. The fungi and bacteria also benefit from the rise in temperature. A recent study found that high ocean temperatures greatly increase the severity of coral diseases White Syndrome on the Great Barrier Reef. It only takes 1-2 degrees C difference to trigger White Syndrome outbreaks.

Disease outbreaks only occurred on reefs with high coral cover after its especially warm year

s, however in cooler reefs the number of diseases remain vacant.

• The image to the left is a coral disease known as Aspergillosis. The image to the right is White Syndrome disease.

Ocean Acidification:

The Oceans are becoming more and more acidic because of the rapid temperature increase. By burning immense amounts of fossil fuels humans are rapidly increasing the amounts of Carbon Dioxide in the atmosphere. Humanity currently releases nearly fifty billion tons of carbon dioxide into the atmosphere each year. This absorption of CO actually slows climate change, but when the CO2 and water combine they form carbonic acid, which releases hydrogen ions. These hydrogen ions increase the acidity of the ocean water by approximately 30%, and in result the pH is all thrown off. As of the year 2010 we have already lowered the pH of the ocean by about 0.1 units. Even this small decrease makes it harder and more costly for corals to secrete their calcium carbonate skeleton. Several experiments have demonstrated that even the smallest decrease pH can disrupt coral growth. This effects the corals ability to compete with other flourishing sea life, like sea weeds and sea sponges. Scientists at the Great Barrier Reef in Australia have found that coral's ability to build their exoskeletons has slowed more than twenty percent in just the last sixteen years. In more acidic oceans the corals existing calcium carbonate exoskeletons will simply dissolve if the pH level becomes too great. This would have significant consequences for the many other species that depend on reefs for habitat and food. Many of the scientists who now study ocean acidification worry that this phenomenon might be far more destructive to reefs in the near term than even climate change.

Human Interference:

Another large factor of coral depletion is the lessoning bond between corals and the fish that live by them. Fishermen are fishing to the extinction of certain species. Humans have already

wiped out 1/3 of the worlds fish stocks. Coral reefs have a complex relationship between the fish, and themselves, both depend on each other. The reefs provide a safe shelter and environment for the fish and in return the herbivorous fish control the amount of algae growing upon the corals.

The fisherman themselves are also to blame for the loss of corals. Blast fishing is used in Jamaica, the Philippines, and Micronesia all use this technique to kill or stun the fish via shock wave, then collecting them as they float to the surface. The bigger fish that most people eat are mostly found by heavily Coral-ed areas because they prey upon their fish there. Blast fishing is used mostly with dynamite. Another new idea thought up by the fisherman is pouring cyanide by the reefs. This stuns the tropical fish and allows for their capture and to be sold to local pet stores. Although it is illegal its a popular black-market job in mostly Asia and Africa. Since the 1960's more then one million kilograms of cyanide have been illegally used in just the Philippines alone.

• The picture to the left is an example of what blast fishing looks like. The picture to the left is a result of that. The turtle is no longer alive with pieces of its shell, and body missing because of the blast.

Pollution:

The role of pollution has always played a role within the changes of the earth. Tropical reefs are only found and able to live in warm water environments with abundant sunlight. These reefs ar

e found in shallow waters along coastlines. Unfortunately, 40% of the world's human

population now lives along coastlines. Approximately 80% of all marine pollution now comes from land-based doings, like agricultural, municipal and industrial runoff. Agricultural and industrial runoff have herbicides and other chemicals that can ha

rm corals. Some even carry excess nutrients that create a algae and phytoplankton bloom, this can lead to the suffocation corals. Of all the pollution washing off the land and into the reef systems, untreated sewage is likely the worst. In Jakarta, the capital city of Indonesia, had enough untreated sewage that had been released directly into the bay "to fill seventy-five Olympic-sized swimming pools each day", noted one biologist.

Section 3: Biography of an Investigator

Jeremy Jackson is a lead investigator for the CENTER FOR MARINE BIODIVERSITY AND CONSERVATION. He is the author of more then 100 scientific publications and has published 5 books. His recent studies include the current loss of the Coral Reefs. Jeremy Jackson is the Ritter Professor of the of Oceanography and the Director of the CFMBAC at the Scripps Institution of Oceanography. He focuses his attention and his research in overfishing, habitat destruction and ocean warming. Most of his findings are most depressing, he has earned himself the nickname of Dr. Doom, he believes that with successful management and conservation strategies we can renew our oceans health, and restore our underwater forests.

Section 4: Impact on Humanity

Coral reefs are important for many different reasons. For starters the coral reefs are

"biologically diverse". This is important because just like the tropical rain forests, coral

reefs may be a source of medicines, chemicals, and other resources that haven't been

discovered yet. The coral reefs are also biologically productive, meaning there are lots

of each organisms that grows there. For example, an organism being an abundance of

lobsters and fish. Some species we may depend on for food. Coral reefs also provide

a beautiful places for scuba or snorkeling. For some countries this is a stable income.

They also provide a protective barrier around many islands and coasts. Without the

reefs these islands and coasts could erode away into the ocean. The coral reefs we have

today CAN'T be replaced. They grow extremely slowly at 1 centimeter a year. The reefs

we have today have formed over 100s of thousands of years, and will take just as long

to grow back because of all the oil drilling and erosion from developing coasts near reefs.

Section 5: Summary of a Journal Entry 

Legal Regime Towards Protecting Coral Reefs: An International Perspective and Indian Scenario

Law environment and development Journal (LEAD)

By Rajesh Sehgal

Summary:

The coral reef ecosystem performs a variety of functions. It provides a safe and unique habitat for fish and protects coastlines from erosion and other natural calamities. The role that coral reefs take place is impossible to impersonate. Within the past decade all over the world the community has already begun to address this crisis. Coral reefs are some of the most ancient

and biologically diverse ecosystems on our planet. Even though they occupy less than a quarter of one percent of the earth’s marine environment, they are home to more than a quarter of all known marine fish species. The reefs are needed for many reasons, they contribute to many countries yearly income because of tourist attractions, as a food source of fish, and as a buffer for large storms. There fore there in an even bigger race to conserve them as quickly as possible. Marine Protected Areas (MPAs) are an important tool for marine conservation and management. MPAs are areas that protect the coral reefs. An MPA may be established for a many reasons, such as maintaining the fisheries through certain ‘no-take’ zones, high species diversity, critical habitat for particular species, or tourist attractions. Some MPAs restrict or forbid human activity within the protected area, while others simply manage an area to enhance ocean use. So far the MPAs seem to be a success, but only time will tell.

Section 6: Conclusion

As you can see from the evidence stated above, coral reefs are more then just a pretty dive sight. They help us in many ways and now it is our turn to return the favor. Coral reefs are home to many different species of plants and animals. They act as a protecting wall against severe storms and other natural disasters, as well as a common food source used by all of the world. One day coral reefs may provide new answers to diseases and lead to other scientific discoveries. Many negative occurrences are effecting our coral reefs, like bleaching, diseases, acidification, pollution and harsh human contact. One day we may be able to save them, as of right now lots of ideas are now starting to be harvested to reassure the waters of their coral beauties.

Section 7: bibliography

"Jeremy Jackson: How We Wrecked the Ocean Video on TED.com." TED: Ideas worth Spreading. Web. 15 Oct. 2010. .

Segal, Rajesh. "Legal Regime Towards Protecting Coral Reefs: An International Perspective and Indian Scenario." LEAD. Web. 14 Oct. 2010.

"Coral Reefs — Global Issues." Global Issues : Social, Political, Economic and Environmental Issues That Affect Us All — Global Issues. Web. 14 Oct. 2010. .

"Climate Change and Coral Reefs: Coral Species Has Developed the 'skills' to Cope with Rising Temperatures." Science Daily: News & Articles in Science, Health, Environment & Technology. Web. 15 Oct. 2010. .

"The Depletion of Todays Coral Reefs." Coral Reefs. Web. 12 Oct. 2010. <"Climate Change and Coral Reefs: Coral Species Has Developed the 'skills' to Cope with Rising Temperatures." Science Daily: News & Articles in Science, Health, Environment & Technology. Web. 15 Oct. 2010. .>.