Endangered Reefs. What is Coral Bleaching?

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1 Endangered Reefs Coral Reefs are among the most beautiful ecosystems on the face of the earth. Thousands of species of fish, invertebrates, corals, and plant life call them home. These animals have an infinite number of different colors, shapes, and sizes. Coral reefs, these days, are in grave danger of becoming nonexistent, and much of the cause of this is due to humans. Some of these causes are ocean acidification, global warming, overfishing, and land runoff. Many of the corals in our oceans are becoming bleached and dying because of these causes. If people were more aware of the impact they have on the worlds oceans and knew what they could do to be more environmentally friendly, then we could begin to revive the coral reef ecosystems. This is a picture of two Naso Tangs in a reef setting, showing the beauty of a coral reef. (Google Images) What is Coral Bleaching? Coral bleaching is the whitening of corals that occurs when algae living within coral tissue are expelled, according to the Wildlife Conservation Society. Coral bleaching can, but not always will, lead to coral death. As many algae s are taking over reefs, they are using up the nutrients that the algae in corals need. What gives a coral its color and food is the algae, and when these algae s are lost or die it causes bleaching. Temperature change is something that it is considered a main cause of coral bleaching, temperature changes, even as small as one degree Celsius (1.8 degree F) could cause the coral to bleach. And after very severe bleaching, the coral will

2 almost always die. During the warmest year ever recorded ( ) there was a mass bleaching event, one in which nearly sixteen percent of the world s reef ecosystems were seriously damaged. The corals that do regain their health and color do so after several months and require an environment that is not very stressful. A coral that does recover could be a coral that does not grow as well and has an abnormal reproduction cycle. This is a picture showing how the Carbon Dioxide gas, specifically from car exhaust, is absorbed into the ocean and turned into Carbonic Acid. ( This means that as we burn more and more fossil fuels, and allow more and more pollution and runoff, the amount of carbonic acid in our waterways and in our oceans will continue to increase until they reach such detrimental levels that marine life will no longer be able to survive. The short-term effects of this increase in carbonic acid levels causes coral bleaching. The warmer waters we are experiencing today, caused mainly by global warming, effects coral skeleton by stunting growth as the increased carbon dioxide levels weaken the coral. When corals are weaker, they are much more susceptible to coral bleaching and eventually, death. Ocean Acidification Ocean acidification is a decrease in the oceans ph levels that is caused by an increase in carbonic acids. Humans have an enormous impact on this increase in carbonic acid because of the amount of fossil fuels that we burn. As we burn these fuels, such as coal, oil, or natural gas, we release carbon dioxide into the atmosphere, and then some of this carbon dioxide is absorbed into the waterways and eventually makes its way to the oceans. As this carbon dioxide reacts with the water, it then forms into carbonic acid. Dr. Ken Anthony of the ACR Centre of Excellence for Coral Reef Studies said, As carbon dioxide levels climb to parts per million as they are expected to do by 2050 how well we manage our local impacts on reefs, like fishing and runoff, will become absolutely critical as to whether they survive as coral reefs or are taken over by algae s, (from Dr. Ken Anthony in Acid Oceans Demand Greater Reef Care at Science Daily). This is a picture showing coral bleaching underneath the surface near an island in the Pacific Ocean. (Science Daily)

3 Global Warming Global warming, put very simply, is the rising of the Earth s temperature. The burning of fossil fuels and deforestation are two of the main causes. These are causing an increase in heattrapping greenhouse gases in the Earth s atmosphere. The Wildlife Conservation Society has released initial field observations that indicate a significant rise in the surface temperature in Indonesian waters has resulted in a large-scale bleaching event that has devastated coral populations, (from Massive Coral Mortality Following Bleaching in Indonesia at Science Daily). These findings by the WCS mean that global warming is having an adverse effect on our reefs. Indonesia is only the beginning of this. The WCS Indonesian Marine Program Director Dr. Stuart Campbell had this to say, It is a disappointing development particularly in light of the fact that these same corals proved resilient to other disruptions to this ecosystem, including the Indian Ocean Tsunami of Another example of this rise in sea surface temperatures is the Andaman Sea. The Andaman Sea is an area that includes coasts of Thailand, Myanmar, northwestern Indonesia and many islands. The National Oceanic and Atmospheric Administration s (NOAA) Coral Hotspot website reported temperatures peaking in May of 2010 when they were nearly four degrees centigrade above the regions average. This worldwide event has devastating implications for the coral reef system. If we continue along this path then many or all of the reefs around the world could be dead within our lifetimes. This is a graph showing the temperature above normal of the Indian Ocean on May 13, This is around the same time that a large-scale bleaching event occurred (NOAA/NESDIS)

4 Overfishing Overfishing, as defined by overfishing.org, is Catching too much fish for the system to support, which leads to an overall degradation to the system. Fishing fleets being too large causes overfishing essentially. The fishing fleets we have today are two to three times larger than they would need to be to catch the amount of fish the world consumes each day (overfishing.org). Why is overfishing a problem? Most of the fish that humans eat are considered consumers. This means that if we deplete a certain species by so much then their will begin to be an over-abundance of the fish that they eat, and the fish that they eat, etc. All the way until we get to the reef fishes. Reef fishes are important because they keep algae s in check, keep the corals in check, and maintain a certain balance in the reef. With these fishes gone, there is no balance, which eventually means, there is no reef. This shows a typical drain that is flowing into a creek, which will flow into a river, which will flow eventually into the ocean. (Google Images) This shows how many fish one boat will catch on a single trip out to sea. And most fishing fleets have over one hundred ships. (Google Images) Land Runoff Land runoff is pollution coming from humans into rivers, streams, etc. and eventually ending up in the oceans destroying reefs. Some of the pollutants include garbage, nuclear waste, sewage, and many others. It seems like something that is so simple to fix, but yet our governments are making it so difficult. Nearly everyone, at least in our country, probably does not even know where our sewage, garbage, and other wastes even go. If they knew this, they might be more careful. The ACR Centre of Excellence in Coral Reef Studies said, Global acidification and global warming will combine with local impacts like nutrient runoff to weaken coral reefs right when they are struggling to survive, (from Acid Oceans Demand Greater Reef Care at Science Daily). Land runoff is just one more thing that weakens the reefs and makes them more susceptible to bacteria s, algae s, and death. This is something very local and something that should be very easy to change.

5 What Can You Do? There are many things that we can do that are not very practical for many people. These things include but are not limited to: buying a hybrid or fully electric car, starting a worldwide campaign to end pollution, or run for President and change the policy if or when you win. Some of the smaller scale thing we can do are: join a conservation group in your community, plant a tree, inspire others to think about the environment, carpool, find out where you sewage goes, do not litter, recycle, volunteer to pick up trash along the highway one afternoon, and many others. As long as we are more aware of our own personal impact, and the impact of all other humans, on the environment then we are taking a step in the right direction. Another thing that we can do is to not use chemically enhanced pesticides or fertilizers because of the runoff. Don t only join a conservation group but support them and help them spread the word, the more people that know about the reefs, the better. One thing that many people don t think about but many should do is conserve water. Conserving water means that not as much will waste water there is and less of a chance to pick up pollutants or chemicals on its way to the ocean. And when you are visiting beaches or coral reefs make sure that you follow all local rules and regulations. This is a picture that we see so often, obviously reminding us the importance of recycling. (Google Images) This is the logo for the Wildlife Conservation, one of the many conservation groups in the United States. (WCS website) Conclusion We are putting the world s most beautiful ecosystem in danger everyday. Things like driving, littering, and flushing a toilet are a few of the many things that could be changed to aid the reefs. Many people do not know the beauty of the reefs, but for the few that do, it is something that should not be slowly killed. If we as a species, Homo sapiens sapiens, were more aware of the impact that we have on the world s oceans, then we could begin to revive the world s coral reef ecosystems.

6 Bibliography ARC Centre of Excellence in Coral Reef Study. Acid oceans demand greater reef care. Science Daily 17 February February Goreau, Thomas J., and Raymond L. Hayes. Coral Bleaching and Ocean Hot Spots (1994). Web. 27 Mar Wildlife Conservation Society. Massive coral mortality following bleaching in Indonesia. Science Daily 17August February Wildlife Conservation Society. "Conservationists develop coral 'stress test' to identify reefs more likely to survive climate change." ScienceDaily 22 March March 2011 < /releases/2011/03/ htm>. Williams, Lucy B., and Ernest H. Williams. Coral Reef Bleaching. Sea Frontiers 34.2 (1988): Print These are all pictures that I took of my aquarium at home.