Coral Reef Depletion

 

 

Coral reef eco-systems are an integral part in the cycle of life in the oceans. Reef systems are the foundation for the marine life and an economical means for many regions of the world. These systems provide shelter to numerous types of fish species and sustain the global biological cycles and balance within our oceans. Without these reef systems many species of fish would die resulting in a tremendous ecological disaster. The current depletion trend is becoming of grave concern to numerous scientists and interested parties. During the past few decades� scientific studies have shown an alarming and disastrous rate of depletion for these highly important zones. With such a wide-range of contributing factors, only the quick action of the scientific community, resource managers, and volunteers will prevent such a catastrophic outcome. Experts have estimated that forty percent of the world�s coral reef systems will be lost by 2010 due to climate related bleaching, pollution, and disease.

 

Ecological Roles of Corals

Coral reef systems are among the ocean�s most complex and misunderstood ecosystems in the world. These systems play an integral role sustaining the biological diversity, global biogeochemical cycles, and provide a beautiful marine ecosystem for tourist and persons alike throughout the world to visit. The reef system is an ideal habitat for fish and many invertebrates providing the shelter and feeding grounds for a plethora of marine organisms. The biological diversity of the reef system is as important as the rainforest providing important scientific insight into the nature of symbiosis, animal behavior, and pharmaceutical drugs. These systems provide the scientific community with many of the life-saving medicines used in common medicine today. Anticoagulants and anticancer agents, such as prostaglandins are derived from Caribbean sponges used in the treatment of herpes simplex and many types of cancers. Hard corals have also been used to replace shattered bones for those patients that conventional technology does not allow. Because the human body more readily accepts coral than artificial replacements, hard corals are an ideal treatment for such injuries.

 

Coral Reefs

Coral structures are built over thousands of years by miniscule animals called polyps aided by small algae called Zooxanthellae that live in their tissues. As with most corals, the hard external carbonate shell commonly observed in the ocean and aquariums are formed by calcifying algae that is formed by calcium carbonate deposited mainly by calcareous algae and stony corals which resemble interconnected sea anemones.

 

Reef systems typically develop in shallow and clear tropical waters. They occupy only two tenths of the oceans total area and are inhabited by at least twenty-five percent of all marine species. There are approximately 7,000 reef systems in the world spanning an area of more than 100 countries and occupying approximately 600,000 square miles of ocean. The large majority of reef systems grow only within a 30 degrees north and south latitude of the equator, commonly known as the tropical regions. Coral systems reside in waters that range in temperatures from about 20� to 35� Celsius and are very sensitive to salinity changes. These systems only survive in a relatively narrow range of tolerances to changes in the environmental conditions.

Coral Requirements

Coral reef systems require relatively clear water for photosynthesis to occur allowing for coral development. Waters in and around these systems are characteristically very low in nutrients such as phosphorus, nitrogen, and other potentially deadly trace elements. Low nutrient levels are required to prevent excessive growth and accumulation of phytoplankton and several types of seaweeds that hinder coral growth. Seaweed and algae populations tend to overgrow corals when there are high concentrations of nutrients present in the waters corals inhabit. Plankton blooms also occur when there are excessive amounts of nutrients present, decreasing the available light to corals and eventually killing them. The majority of coral nutritional requirements are via the translocation of metabolites from photosynthesis. A reduction of the available quality or quantity of light will affect coral nutrition, growth, reproduction, and depth distribution. These narrow physiological limits in development make corals very susceptible to climatic change. Changes associated with global warming such as El Ni�o/La Ni�a, increased pollution, and water quality changes have and could destroy most if not all the remaining coral systems throughout the world.

 

Coral Depletion and Protection

There is the growing possibility that within the next 30 to 50 years the coral reef systems in the world�s oceans could be wiped out. A group of scientist known as the U.S. Coral Reef Task Force were formed at the Convention on Biological Diversity conference at the United Nations Conference on Environment and Development in Rio de Janeiro in June of 1998. President Clinton issued the Executive Order 13089 on Coral Reef Protection to preserve and protect the biodiversity, health, heritage, and social economic value of U.S. coral reef ecosystems and the marine environment. The task force composes of eleven federal agencies and the governors of seven states. On March 2^nd of 2002 the Coral Reef Task Force unveiled the first ever National Action Plan to comprehensively and aggressively address the most pressing challenges facing coral reefs today.

 

As a response to the growing global environmental crisis of coral reef depletion the Task Force has worked with the scientific community to develop and implement a program of research aimed at identifying the major causes and consequences of numerous contributing factors. Organizations such as the National Oceanic and Atmospheric Administration (NOAA) have taken positive steps in the implementation and management to prevent further degradation of these systems in co-operation with the Task Force. The U.S. Coral Reef Task Force has been assisting NOAA in the preparation of the National Coral Reef Action Strategy. As a result of these actions several zones have been created by NOAA to protect habitats and species by limiting consumptive and conflicting user activities to allow resources to evolve in their natural state with minimal human interference and influence. The Coral Reef Task Force is responsible for developing and implementing coordinated efforts to map and monitor coral reef research. It will attempt to establish the causes of coral depletion and to implement solutions and strategies to promote conservation and sustainable use of coral reefs internationally.

 

Scientist off the coast of Florida is initiating the first ever detailed census of a local coral population in a study that may allow for the prevention of the worlds dwindling coral reefs. The team consists of researches from the Universities of Buffalo and Miami. These teams are studying the Conch reef system in efforts to establish and prevent mortality of reefs.

 

Contributing Factors

There are numerous factors that account for the depletion coral reef systems. Many of these causes can be attributed to anthropogenic sources. Slight changes in the reef environment may have detrimental effects on the health of entire coral colonies.

 

Human expansion and development is one of the greatest threats to these systems. The exploding population along the vast number of coastal regions has caused a severe buildup of sedimentation and urban runoff into zones where reef zones are located. Runoff from land development, agricultural practices, outflows from power plants and treatment facilities are the main causes for the mortality of these reef zones.

 

The exponential growth of populations in the world has increased from 5 billion in the 1980�s to more than 6.9 billion people at the turn of the century. In 1990, 3.6 billion people lived by coastal areas. Projections have predicted that by 2025 the coastal population could increase to 6.4 billion people. The problem is far greater than the simple population explosion. The vast majority of third world populations reside on the coast on or near by reef systems. These locations have grave problems with their resource management and removal of waste and treatment of water expelled into the ocean. Outflows from water treatment plants and large power plants cause much damage to reefs as well. Treatment facilities increase nutrient levels surrounding their outflow pipes while power plants alter water temperatures by discharging extremely hot water into coastal regions on and around reefs. Most large coastal populations also generate a large amount of coastal industrial waste causing a great deal of pollution. The large amounts of sediment run-off from land-clearing practices, high levels of nutrients from agricultural areas, septic pollution, and pollutants from petroleum and insecticides makes it impossible for corals to recover and survive from diseases. The small introduction of waste by watershed yields large repercussions to coral zones because of their narrow physiological limits of survival.

 

Nitrogen and Phosphorus are normally limiting factors for the growth of plants. When excess amounts of human introduced nutrients are expelled into the marine environment outbreaks of algae could occur. These outbreaks are known as algal blooms which are commonly caused by Eutrophication. An alga covers corals reducing water exchange and photosynthesis causing the coral to expel and reject their Zooxanthellae which are needed for survival. The further increase of these limiting agents also encourages the growth of dinoflagellates and diatoms which devour coral. The wide use of pesticides and fertilizers has detrimental effects on corals as well. Pesticides cause an increase in respiration rate and a decrease in oxygen and photosynthesis. Nitrophication results from the excess of organic waste. Decomposers process the waste respiring and consuming much of the dissolved oxygen in the water. This leaves little or no oxygen for fish and marine life to thrive upon ultimately resulting in death. Inputs of organic waste also decrease salinity which coral are particularly sensitive to and results in the mortality of corals as well.

 

There are many destructive practices used to catch fish that results in the death and destruction of many reef zones. Some of these practices include the over fishing of numerous regions throughout the oceans. As the worlds population increases the demand for the harvest of these resources increase. Fish reef populations have been greatly reduced throughout the world by the use of aggressive methods and techniques employed to catch marine fish. A number of practices used for fishing have created numerous problems in reef zones. Over fishing has diminished the breeding of many types of fish below minimum numbers needed for acceptable recruitment of young fish. Numerous species of marine inhabitants throughout the world are in record lows. These marine inhabitants keep algal growth under control by eating much of it off of corals. The removal of these fish have caused many coral reef ecosystems to become unbalanced and allowed more competitive organisms to become dominate entities in many reef regions destroying them.

 

Many fisheries throughout the world such as in Indonesia use Sodium Cyanide as a means of collecting fish in reef zones. This substance is squirted into or near reefs causing the fish to lose their equilibrium and swim uncontrollably out of the nooks and crevices. Blast fishing is perhaps the most destructive method employed. It instills using dynamite and exploding it in the water on or near reef zones. The method is very non-selective and kills anything within the proximity of the blast. It kills juvenile fish, adult fish, and destroys many of the precious corals around the blast. Although much of the coral reef degradation is directly the result of human practices and impacts, there are also several natural disturbances that cause significant damage to coral reefs. The most recognized of these events is weather changes such as, hurricanes, and annual weather trends.

 

It has recently become acknowledged that much of the decline in coral reef systems can be attributed to natural oscillations in the world�s climate that occurs every 26 million years and results in major extinctions and fluctuations in reef communities. The more obvious of these is the El Ni�o and La Ni�a cycles that occur about every four years. Until relatively recently global warming has become an added threat the worlds reef systems. In 1998 scientist throughout the world got a disturbing look at what lies ahead of us if the current trend continues to occur. If the reef zones were to be depleted it would constitute eradicating a branch of the food chain. The world�s waters would fall out of equilibrium by the destruction of these reef systems causing an ecological disaster.

 

It is believed that nearly all species of corals were and still are affected by the high sea surface temperatures during the 1998 El Ni�o occurrence which has lead to global coral bleaching and mortality. If climate change is not reduced or stopped, the frequency and intensity of the weather phenomenon could occur annually by 2030 � 2070. This would devastate coral reefs globally to such an extent that they could be eliminated from most areas of the world by 2100. Current estimates suggest that reefs could take hundreds of years to recover. The loss of these fragile ecosystems would cost billions of dollars in lost revenue from tourism and fishing industries, as well as damage to coastal regions that are currently protected by the coral reefs lining most tropical coastlines from natural phenomenon.

 

Diseases

Florida is among the only state in the Continental United States to have a live and growing coral reef system. The importance of sustaining this system and many others is of the utmost importance. These reef systems harbor many important and non-renewable resources. Several state and federal organizations such as the National Oceanic and Atmospheric Administration (NOAA) have noted an invasion of algae into sea grass beds and onto other coral zones within the Keys and numerous other regions throughout the world. As a result, in the past few decades the Florida Keys have befallen victim to a decline in coral health indicated by the increase of coral diseases such as black-band, coral bleaching, bacterial infections, and shut-down diseases. Widespread diseases such as these have been observed in both the Atlantic and Pacific oceans with a decreased living coral cover on and around these rare ecological systems. Many of these diseases maybe the direct result of stresses caused by human introduction into these zones.

 

User Groups

Underwater recreation such as scuba has become a popular sport that has been exploding throughout the world. The dive industry has exponentially grown while dive resorts and scuba throughout the world have become an enormous part of many community�s economies. With the advent of these new destinations have come numerous tourists. Recreation and tourism are the dominant economic sectors of the Florida Keys and thousands of other destinations throughout the world. Recreational activities range from boating, fishing, scuba diving, and snorkeling.

 

The vast majority of experienced and novice divers are not aware of how fragile coral reef eco-systems are and how much damage diving un-conservatively could cause. There is no definitive answer to how much damage is being caused by divers; however it is certainly causing some damage by our presence. Damage to the reef systems includes both physical and indirect damage. Many regions of the Florida Keys are experiencing strains upon many of its coral systems. In response to the many strains caused by either dive intrusion or other factors, several artificial reefs have been created to relieve the strain on the damaged or over-dived reef systems.

 

The dive industry is addressing its concerns of diving stress upon reef systems and is taking the leading steps in the prevention and promotion of preserving corals. The dive industry has taken positive steps in the education and promotion of diver awareness, which focuses on the protection of reefs and surrounding biology. With the advent of new technologies and methodologies the education and promotion of safe diving has become a more tangible step with the prevention of coral strain in the dive community. Informing divers of the delicate balance reefs thrive in has motivated numerous communities to take responsibility for the protection and preservation for both altruistic and economic reasons. The dive community is a significant economic resource that has shed light on many environmental issues that threaten the reef systems and many other issues.

 

The impending threat of extinction of one of the worlds most resourceful and beautiful underwater rainforests is just now becoming recognized by the scientific community and interested parties. Preserving these zones has become a grave concern for both the economical prospect and ecological standpoint of a possible loss of equilibrium in our oceans. These eco-systems are extremely fragile and the monitoring and preservation of these sites may be the only hope for our future generations of children to enjoy and admire the vast beauty and resources coral reefs offer. Coral reef zones represent the only type of eco-systems on the Earth with such complexity and resources. The preservation and sustaining of such these resources will hopefully be here for the future generations to come.