Coral Reef Extinction
University of Denver
MALS 4020 Graduate Research and Writing
May 31, 2010
If the average person on the street expressed their opinions or ideas on the topic of the coral reefs, what might immediately come to mind are images of vacationing in Australia, scuba diving, snorkeling, and enjoying the abundant life that lives in the ocean. The general public has had little reason to ponder the purpose of the coral reefs except for how beautiful they are to view, swim around, and look vivacious in a photograph. At times, the public has had instances of exposure to the true function of the coral reefs through news clips on television or the Internet on oil spills, shortage of seafood, or watching a documentary on the Discovery Channel (Discovery Communications 2010). This is when reality sets in with human consciousness that the coral reefs provide a vital function to the coral ecosystem (NOAA 2010) and to this planet and is not just here for its beauty. Media exposure is providing illustrations of the current issues directly involved with the coral reefs.
This paper will provide a brief overview and background of the coral reefs and why they are vital to this planet. Then we will examine the importance of the coral reef ecosystems, such as their biodiversity, coastal protection, and economic value. Once we have established the value of the coral reefs, the paper will briefly summarize the causes and results of coral reef damage. Finally, we will discuss changes that must be enacted, opposing opinions, and possible innovative solutions exist to counteract coral reef damage.
Pollution, overfishing and increased oceanic acidification are causing the extinction of the coral reefs and unless immediate changes occur by everyone to halt the damaging human activities and repair this vital marine biosphere the extinction of the coral reefs will cripple the world economy and cause mass starvation.
First, it is important to understand the composition and history of the coral reefs. This information sets the stage for the discussion as to why the coral reefs are vital to the ocean's ecosystem and mankind's economy. To know about the coral reefs is to learn about their background and how important they are to this planet’s future.
Overview and Background
Coral reefs have existed on the planet for approximately 450 million years and provide an extremely diverse marine ecosystem (Bellwood and Wainwright 2002). Coral reefs are the largest natural structures in the world, and are the result of a remarkable relationship between coral animals (known as polyps) and microscopic algae (known as zooxanthellae) living within the coral tissues (Withgott and Brennan 2008). The zooxanthellae convert sunlight and carbon dioxide into oxygen and carbohydrates. Polyps use carbohydrates to make calcium carbonate in a process known as calcification. The calcium carbonate forms the skeleton of tiny colonial marine organisms known as corals (Withgott and Brennan 2008). Most coral polyps have clear bodies and their skeletons are white, like human bones. Their brilliant color comes from the zooxanthellae living inside their tissues. Several million zooxanthellae live and produce pigments in just one square inch of coral. These pigments are visible through the clear body of the polyp and are what gives coral its beautiful color. If the zooxanthellae were to disappear, depriving the coral of nutrition, the coral reef will undergo bleaching leaving ghostly white patches as they lose color and die. Coral reefs return the favor by providing food and shelter for thousands of organisms which co-exist in complex interconnected food chains. Pollution, overfishing, and increased acidification will ruin this relationship forever by killing organisms with toxins, interrupt the ecosystem through seafood extinction, and acidification will deprive coral of the carbonate ions (Coral Reef Alliance 2010) which play an important role in shell formation for the corals in order for them to produce their structural parts. By understanding the coral reefs history and background we can learn why the coral reefs are important to the ecosystem.
Importance of the coral reef ecosystems
Even though coral reef organisms have different behavior patterns, they all interact as members of the same marine ecosystem and participate as friendly neighbors by sharing common objectives of protecting their space to feed and reproduce. Coral reef ecosystem biodiversity is in a constant state of change since various sea creatures such as sponges, bivalves, urchins, and fish live or feed on the different parts of the coral reefs and are all part of one tropic level or rank in the feeding hierarchy (Withgott and Brennan 2008). Each tropic level provides energy for the next level; from the coral reefs to seafood such as crab, lobster, and fish. When humans consume seafood they are also consuming energy from every organism up the food web from the coral reefs. If corals are damaged by pollution, overfishing, or increased acidification the complex equilibrium of the reef will be permanently altered. Once biodiversity at all levels of the ocean life is lost to human impact, extinction occurs. Extinction is a normal process; however, humans are assisting the process along at a rapid speed. The result is loss of productivity and biodiversity, both of which having a serious economic consequence (NOAA 2010).
Coral reefs provide a function to our coastlines; they protect shorelines by absorbing wave energy and provide food and shelter for fish and other sea creatures. Biological structures, such as mangrove forests, salt marshes, seagrass beds, and coral reefs calm waves and, as a result, provide coastal protection. Corals also create shelter for mangrove and seagrass growth (Koch et al 2009). Without the coral reefs, tsunamis and ocean storms can destroy the coastlines such as happened in the Maldives in the Indian Ocean.
The recent BP oil spill in the Gulf of Mexico (Dearen and Senensky 2010) discharged plumes of oil over the coral reefs along the coastline and marine scientists fear that Gulf currents will carry the oil to other reefs along the Florida Keys, Louisiana, and as far as Texas. Due to the political controversy over offshore drilling, this type of catastrophic disaster should have been avoided due to lessons learned from the Exxon Valdez spill. The U.S. Environmental Protection Agency briefly allowed BP to shoot massive amounts of potentially toxic dispersing chemicals deep underwater to help protect vital marshes and wetlands on the Gulf Coast. But the tradeoff may result in significant effects on more sea life, including the coral reefs (Dearen and Senensky 2010). Big corporations such as BP and other oil moguls focus on profit rather than on ocean life when making decisions on offshore drilling. Wildlife protection takes a backseat to oil-company profits.
Coral reefs have an important function in sustaining the fish and shellfish populations that provide protein for billions of people. For thousands of years our ocean life has been a part of our lives, from watching the animal life move in the ocean to catching them for profit and food.
Coral reefs are a source of medicine by providing new compounds and technology to treat serious diseases. The National Oceanic and Atmospheric Administration (NOAA) (2010) says that nearly half of the medicines in use today have their origins in natural products, mostly derived from terrestrial plants, animals, and microorganisms. Creatures found in coral ecosystems are important sources of new medicines being developed to induce and ease labors; treat cancer, arthritis, asthma, ulcers, human bacterial infections, heart disease, viruses, and other diseases, and provides sources of nutritional supplements, enzymes, and cosmetics.
Coral reefs attract millions of visitors spending billions of dollars annually creating economic value to the local communities by scuba diving, snorkeling, diving tours, recreational fishing trips, hotels, and restaurants. Coral reefs can be enclosed as marine protected area (MPA) to preserve them for divers. The Similan Islands, also known as Mu Koh Similan Marine National Park off the coast of Thailand, became a MPA in 1982 where the coral reefs play a significant role in maintaining ecological stability and preserving biological diversity of flora and fauna, as well as offering visitors a variety of attractions for recreation and education. Over 50,000 tourists flocked to the islands back in 2003 to enjoy the beautiful, seemingly untouched, and uncommercialized natural conditions of the Park’s flora and fauna. Tourism at Mu Koh Similan Marine National Park generates the highest revenue compared to other national parks in Thailand and scuba diving is one the major tourist attractions that brings in significant revenue to the Park each year (Tapsuwan and Asafu-Adjaye 2008).
In the next section, we will examine the causes and results of how human have impacted the coral reefs through pollution, overfishing, and ocean acidification.
Causes and results of the coral reef damage
Pollutants, such as oil or toxins, originating from land and sea are responsible for significant lethal and sub-lethal effects on marine life. Pollution impacts all trophic (nutritional) levels of marine life, from primary producers (plants) to top predators (whales), and interferes with the structure of marine communities and the ecosystem functionality (Todd et al. 2010). Oil tankers leaking oil make up a big part of ocean pollution (Lauinger 2010) and can kill or harm the animal life that live within and care for the coral reefs. The oil coats the polyps on the coral reefs and block out sunlight; when the light is blocked, the photosynthesis seizes up and everything that relies on it dies. All of the dead organisms begin to decompose which produce bacteria that use up the oxygen that is needed for the coral reefs to survive. With this type of pollution there is no way that coral reef organisms can acclimatize themselves to increasing atmospheric carbon dioxide levels (American Geophysical Union 2000).
Pollution also originates from a main point on a river, flows down, collecting more pollution as it goes from sources such as agriculture, animal feedlots, urban neighborhoods, factories and disposal sites, construction sites, and mines, and disburses all of these toxins at the mouth of an ocean. Fertilizers, pesticides, and herbicides containing nitrogen and phosphorus accumulate from agriculture and are flushed down the Mississippi River and into the ocean. These excess nutrients urge drifting organisms to flourish in the Gulf of Mexico causing a depletion of oxygen (hypoxia) in the ocean known as the “dead zone” (Withgott and Brennan 2008). Nutrients, waste, and bacteria from animal feedlots; salt used on roads during winter season, oil, grease, and chemical from urban runoff; industrial waste and toxic chemicals from factories and disposal sites; eroded soil from construction sites, deforestation, and overgrazed land; and acid drainage from abandoned mines eventually filter out to the Gulf of Mexico and harming the coral reefs and sea life.
Since pollution has a negative impact on the coral reefs, there are solutions to this issue. Federal legislation created the Federal Rivers and Harbors Act of 1899 to restrict dumping and discharges in navigable waters, and the Federal Water Pollution Control Act of 1972 (amended to the Clean Water Act in 1977) makes it illegal to discharge pollution from a point source without a permit and sets standards for industrial wastewater and contaminant level in surface water and funded construction of sewage treatment plants (Withgott and Brennan 2008). These Acts have assisted with solving the problem of adding additional pollution that would harm the coral reefs.
Since we learned how pollution is damaging the coral reefs, next we will examine how overfishing can prove to be a harmful affect to the coral reefs.
Coral reef fisheries support tens of millions of people worldwide, mostly in developing countries (McManus et al 2000). Rapid human population growth, demand for fishery resources, use of efficient fishery technologies, and inadequate management and enforcement have led to the depletion of key reef species and habitat damage in many locations, such as the Florida reefs (National Oceanic and Atmospheric Administration 2010).
Overfishing has caused ecological unsustainability due to people depleting fish faster than they can be reproduced. Fishing on reefs is classified into three stages: manageable, ecosystem-overfished (decline of once abundant fish stock), and Malthusian-overfished (use of illegal gear such as blasting devices and poisons, such as cyanide). The latter type of fishing occurs when a hand-made bomb, consisting of chemical fertilizers such as potassium nitrate or in the form of a dynamite stick, is thrown into a coral reef area to stun any fish in the immediate area. After shocking the fish, the divers collect them by hand (Burns 2003).
The Fishery Conservation and Management Act of 1976 created the Gulf of Mexico Fishery Management Council (2010) and it has made a positive impact on overfishing by creating fishery management plans and amendments designed to manage fishery resources. The plans or amendment regulate the amount of fish that are harvested in order to maintain the best interest of the people of the United States. On January 12, 2007, former President Bush signed the Magnuson-Stevens Fishery Conservation and Management Reauthorization Act of 2006 to mandate the use of annual catch limits and accountability measures to end overfishing, provide widespread market-based fishery management through limited access privilege programs, and calls for increased international cooperation (NOAA 2010).
An opposing argument on overfishing comes from fishers and the fisheries that make a living and profit off fishing. Cod fishing was once abundant off the shore of Labrador and Newfoundland; unfortunately, due to hundreds of years of overfishing from trawling (dragging nets through the water with weighted nets across the floor of the continental shelf) the cod started to disappear and trawling caused severe structural damage to the coral reefs and its habitat. On July 2, 1992 Canadian Fisheries Minister John Crosbie announced a two-year ban on commercial cod fishing. Without jobs, the fishers’ lost income and relied on unemployment benefits and coastal communities faced economic ruin. However, this negative impact created a positive outcome; the fishers were offered alternative training for new skills and incentives for early retirement (Withgott and Brennan 2008). We learned how overfishing has proved to have negative impacts on the coral reef; the third area of concern is ocean acidification.
Acidification damages coral reefs and has other chemical and biological consequences. The acidity of oceans is changing very rapidly. The hydrogen ion concentration of surface ocean water (a reflection of pH) is now about 30% higher than it was 200 years ago. Princeton University researchers (Potera 2010) found that ocean acidification has negative impacts on the tiny one-celled plants which reside at the bottom of the food web and support commercially important fisheries. Researchers are finding that with a low pH balance, phytoplankton take up less iron, a key nutrient needed for photosynthesis and growth (Potera 2010).
According to Saunders (2010), human industrial activities contribute to climate change and to the CO2 generated that is absorbed by the world's oceans. CO2 reacts with seawater to form carbonic acid which decreasing the hydrogen-ion (pH) concentration of seawater and leading to environmental degradation. This includes damage to coral reefs and the inability of the ocean to absorb low-frequency sound, which sea life relies on as a channel of communication.
In the past 200 years the oceans have absorbed approximately half of the CO2 produced by fossil fuel burning and cement production. If emissions from human activities continue to rise, the average acidity of the oceans might increase by 0.5 units by 2100 causing devastating effects to the marine biosphere (Cribb 2008).
Now that we have read about pollution, overfishing, and ocean acidification, we will examine the changes needed to prevent coral reef extinction.
Changes to Prevent Extinction
The coral reefs are part of the foundation of the ocean food chain and are eaten or inhabited by many sea-going creatures, not to mention (Donovan 2010) provide services with an average annual value estimated at $172 billion (Ecos 2009) to millions of people worldwide that depend on coral reefs for their food and livelihood (Skoloff 2010). Preventing extinction takes investment. Investing money in coral reef restoration can provide a great rate of return by working with the coral reef instead of killing it. It is difficult to put an exact price on the coral reefs except for calculating the amount of negative impacts that can happen if we did not have the coral reefs. The ecosystem, coastlines, jobs, tourism, and food supply would suffer immensely without the coral reefs. Investment is necessary in qualified worldwide environmental organizations to clean and purify the existing ocean pollution correctly and fund federal regulations and policies to prevent pollution.
The U.S. Environmental Protection Agency (2009) offers solutions to repair damage and prevent further extinction to the coral reefs. There has been an increasing effort to establish better management and conservation measures to protect the diversity of these biologically rich areas such as a joint venture with The NOAA (2010) to establish marine sanctuaries. By having both agencies collaborate together, the coral reefs have a great chance of surviving extinction.
Changes are not simple or easy. In addition, the United States is also faced with politicians and businesspeople who will disagree with the idea that pollution, overfishing, and ocean acidification cause coral reef extinction, and believe the issues are an exaggeration. These people tend to look at short-term results and profit rather than long-term consequences. If a catastrophic event occurs, such as an oil spill, the “blame game” is more appealing and disregards personal responsibility. Some people have eyes on the economic value of the coral reefs and disregard the damages that are occurring from their actions.
To change a situation means to find innovative solutions. The next section discusses how we can help solve the problems of the coral reefs.
Innovative solutions are currently being proposed to solve the problems caused by oil and gas development activities in the marine environment. The solutions are based on a holistic environmental approach, which takes into account the complexity of natural processes and also takes advantage of these processes, rather than working against them.
Some of the proposed models include marine protected areas in oil sites (MPAOS), ocean fertilization and CO2 utilization (OFCU), integrated coastal pollution balancing (ICPB), artificial recruitment in fisheries (ARFS), and artificial reefs from oil rigs (AROR). The main goal of these proposed approaches is to maintain and restore ecological sustainability and ecosystem integrity (Khan and Islam 2008, 121-132).
Marine Protected Areas in Oil Sites (MPAOS)
MPAOS are special areas established for conservation, but allow specific recreation and commercial uses, much like national parks. The U.S. Department of Commerce and the U.S. Department of the Interior implemented The National Marine Protected Areas Center in 2000 to develop a Classification System for MPAs to focus on conservation, maintain diversity, cultural value, and permanent protection of the coral reefs. The center’s mission is to facilitate the effective use of science, technology, training, and information in the planning, management, and evaluation of the nation's system of marine protected areas to protect the coral reef from harm (MPA 2010).
Ocean Fertilization and CO2 Utilization (OFCU)
According to Khan and Islam (2008, 126) OFCU can provide a solution by fertilizing the oceans with iron to help phytoplankton growth and increase their environmental range to help control the ecosystem. Iron and silicon can also help with the accumulation of wastes and be used as nutritional sources for marine phytoplankton. The OFCU model has the potential to minimize atmospheric CO2 levels, which may ultimately slow down global warming. The idea is to balance CO2 emissions by sinking enough organic carbon in the ocean bottom by applying this method.
Integrated Coastal Pollution Balancing (ICPB)
According to Khan and Islam (2008, 127) 700 million gallons of oil enters the marine environment yearly, 55 percent enters the coastal areas through runoffs from agriculture such as the Gulf of Mexico. The ICPB model will make use of the runoff oil and pollution through the use of balancing ecosystem components by implementing bioremediation, fisheries, food web enhancement, aquacultures, and seaweed plantation which will require an ecological plan to implement. The total number of pollutant inputs can be estimated in a selected area such as runoff oil, agricultural waste or municipal waste release, and other industrial pollution, and an ecosystem model would be developed to use those pollutants. Due to their nitrate and phosphate discharge, plants such as seaweeds and other algae can be planted in such a way that they play a role in the phytoremediation of drainage oil as well as oil (or oil products) released from nearby sources. If agricultural or industrial pollution increases, seaweeds and other plankton can go into production overdrive. To control phytoplankton growth, herbivorous fish can be shipped in to control this trophic level. Mussel farming can be set up to control the number of plankton particles in the water. By controlling all levels of the marine environment, an overall ecosystem can be developed in the selected coastal areas (Khan and Islam 2008).
Artificial Recruitment in Fisheries (ARFS)
By studying the stock assessment at oil and gas development sites, one can estimate the status at fisheries and any possible negative scenarios that can impact a particular site. The ARFS method compensates fishery production if anything happens as a result of oil and gas development by helping to increase the existing fish stocks and transplant species in targeted areas such as development sites or an alternative site. This allows fishermen to extend their fishing activities into open waters such as lakes, reservoirs, rivers, seas, and oceans. The main objective of the ARFS is to increase the fish stock of selected species through artificial propagation of seed (fish larvae) in targeted areas and to resuscitate the stocks of over-fished or environmentally altered bodies of water. It will fill ecological niches, use biological resources, and compensate for the effects of barriers on the migratory routes to spawning grounds (Khan and Islam 2008, 128).
Artificial Reefs from Oil Rigs (AROR)
In the last model, AROR will use different types of oil rigs to be installed according to water depth. Oil rigs are huge structures and weigh thousands of tons. By law, abandoned rigs must be decommissioned and removed from marine waters. These rigs are usually cut down to manageable size and brought back to the shore. The AROR model can use the rigs as artificial reefs for fisheries yield and production, recreational activity, prevent trawling, repair degraded marine habitats, and overall economic and social benefits. The rigs can be kept at their original sites to establish a reef community or be transported to another planned site, giving a choice of type of seafloor conditions. Existing oil rigs have spawned lush marine habitats that are home to a profusion of rare corals and ten thousand to thirty thousand fish per rig. Oil companies can save between $400 and $600 million per rig by converting them into artificial reefs instead of offshore decommissioning. Using the AROR model is economically profitable and can be implemented with coordination of other governmental agencies.
Investors and organizations need to collaborate and work innovatively to solve the issues of pollution, overfishing and increased oceanic acidification to repair and avoid further damage to the coral reefs to prevent extinction. They may not entirely halt human activity from destroying the ocean but they can create jobs and innovative ideas to slow the process down and prevent mass starvation in the meantime.
The coral reefs have existed for 450 millions years, yet they have been the center of controversy for the last few decades. Even though they are the largest natural structures in the world, human interference threatens their existence. Pollution, overfishing and increased oceanic acidification are causing the extinction of the coral reefs. Unless every person initiates change today to halt damaging human activities and repair this vital marine biosphere the extinction of the coral reefs will cripple the world economy and cause mass starvation. Pollution, overfishing, and ocean acidification will create turmoil socially, economically, and politically if we do not act today and consider future sustainability.
Scientific consensus shows that the coral reefs are on the path to extinction through observation, direct evidence, and collected data; however, time will tell if society can prevent more damage, repair what has already been harmed and become sustainable before the coral reefs disappear forever.
On the other hand, the global economy is also a human concern since society relies on the coral reefs for their value in tourism, medicine, and food for human consumption. While both sides have great points, it comes down to extinction. If we overuse and abuse the coral reefs, they will die.
The solution is for a compromise between extinction and valuing the ecosystems using creativity, innovation, and sustainability. Pollution, overfishing and increased oceanic acidification can be slowed down through new and updated policies environmental laws, sustainability, and investing in new innovative solutions (NOAA 2010).
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