The Coral Reefs Ecosystem Hidden beneath the ocean water, is the coral reefs team of life. Fish, corals, lobsters, clams, sponges, seahorses, sea turtles are only a few of hundreds of thousands of creatures that rely on reefs for their survival. I think that coral reefs are beautiful and I find that ecosystem of a reef is fascinating. Despite the fact that Corals look like rock or plants they are definitely marine animals. Corals life begins in tropical water as floating larvae. After a short period of time the larvae attaches itself to a hard surface and becomes a polyp. Corals are related to the jellyfish some people say that a coral looks like a jelly fish upside down due to a coral having a lot of tiny polyps. A single coral polyp may be as large as a saucer or small as the top of a pinhead. There are billions of polyps working together in a cooperative colony. Generation after generation creating a limestone skeleton that forms the framework of the beautiful coral reefs. Coral Reefs grow very slowly. It could take up to a hundred years for a reef to grow 3ft. (Best&Bornbusch, 2001)
Coral Reefs have been in existence for over 215 million years and located in tropical waters. The earths ocean floors cover more than 70% of our planet's surface and 97% of that water is found in the ocean. As everyone knows ocean water is salty and the reason being is due to the salinity in the water. The two ions found in seawater are chloride and sodium. The salt in the ocean's water has a lot of chemicals in it such as potassium, magnesium sulfate and calcium. There are rocks in the lakes and streams that play a major part in this process. When it rains inland it contains some dissolved carbon dioxide from the surrounding air which causes the rain water to have an acidic carbon. The rain physically erodes the rock with the acid chemically breaking down the rocks and carrying minerals along in a dissolved state as ions. At this point the ions are carried through the waters eventually flowing into the ocean. A lot of organism in the ocean uses up the dissolved ions and some are removed from the water but what is not used up are left for a long period of time where their concentrations increase over time. There are also more sources that produce the ions (salinity) in the ocean waters such as a hydrothermal vent. The hydrothermal vent is on the ocean crest ridges and has recently been discovered to contribute to the process of dissolving minerals due to the crust becoming hotter. Which the minerals flows back into the ocean waters. Submarine Volcanism is another process of salinity in the ocean's water due to the seawater reacting with the hot rock from the volcano eruption that dissolves some minerals to produce the ions into the water.
Different bodies of water have different amounts of salt mixed in, or different salinities. Salinity is expressed by the amount of salt found in 1,000 grams of water. Therefore, if we have 1 gram of salt and 1,000 grams of water, the salinity is 1 part per thousand, or ppt. () The average ocean salinity is 35ppt. This number varies between about 32 and 37 ppt. Rainfall, evaporation, river runoff and ice formation cause these variations. (Reefs&People, 2009)
Scientists estimate that of the coral reefs cover range is 0.01-.0.5% of the ocean floor. (Reefs&People, 2009) The growth of reefs starts small and grows large. They have been found in depths of water less than 150ft where the sunlight can penetrate. Due to the symbiotic relationship with a type of microscopic algae, sunlight is necessary for these corals to thrive and grow. Reef building corals require warm ocean temperatures of 68-82 Fahrenheit. Reefs development is generally more abundant in areas that are subject to strong wave action due to the face waves carry food, nutrients and oxygen to the reef along distributing coral larvae and prevent sediment from settling on the coral reef.
Coral reef are extremely productive, corals reproduce both sexually and asexually. One polyp may use both reproductive modes within its lifetime. Corals reproduce sexually by either internal or external fertilization. The reproductive cells are borne on membranes that radiate inward from the layer of tissue that lines the stomach cavity. Internally fertilized eggs are brooded by the polyp for days to weeks. Free swimming larvae are released into the water and settle within hours. Externally fertilized eggs develop while adrift. After a few days, fertilized eggs develop into swimming larvae which settles within hours to a hard structure. Some corals have both male and female productive cells. Others are either male or female. Both sexes are can occur in a colony, or a colony may consist of individuals of the same sex. Synchronous spawning occurs in many corals. Polyps release eggs and sperm into the water at the same time. This spawning method disperses eggs over a larger area. Synchronous spawning depends on four factors such as time of the year, water temperature, the tidal and lunar cycles. This type of spawning is also done when there is less water movement over the reef such as low tides. Asexually reproduction initiates growth of a colony by budding. Budding occurs when a portion of the parent polyp pinches off to form a new individual. Budding enable the polyp to replicate itself several times and at the same time maintain tissue connections within the colony. Later, the same polyp may reproduce sexually.

The reasons corals are salt water animals verses river water is due to the lack of sunlight due to the mud settling on the reefs.
The coral reef ecosystem is a diverse collection of species that interact with each other and the physical environment. The sun is the initial source of energy for this ecosystem. Through photosynthesis, phytoplankton, algae and other plants' covert light energy into chemical energy. As animals eat plants or other animals, a portion of this energy is passed on. The species that live in or around the reef has an important part to making a healthy reef such as they know “cleaner shrimp” It removes parasites and dead skin from reef fishes. Both schooling and solitary fishes are essential resident of the reefs ecosystem. Fishes play a vital role in the reef’s food web, acting as both predators and prey. Their leftover food scraps and wastes provide food and nutrients for other reef inhabitants. Parrotfish use a chisel like teeth to nibble on hard corals. These fish are herbivores and eat algae within corals. They grind the coral exoskeleton to get the algae, and defecate sand. One parrotfish can produce about five tons of sand per year. (Best&Bornbush, 2001)
Coral reef are extremely productive, corals reproduce both sexually and asexually. One polyp may use both reproductive modes within its lifetime. Corals reproduce sexually by either internal or external fertilization. The reproductive cells are borne on membranes that radiate inward from the layer of tissue that lines the stomach cavity. Internally fertilized eggs are brooded by the polyp for days to weeks. Free swimming larvae are released into the water and settle within hours. Externally fertilized eggs develop while adrift. After a few days, fertilized eggs develop into swimming larvae which settles within hours to a hard structure. Some corals have both male and female productive cells. Others are either male or female. Both sexes are can occur in a colony, or a colony may consist of individuals of the same sex. Synchronous spawning occurs in many corals. Polyps release eggs and sperm into the water at the same time. This spawning method disperses eggs over a larger area.
Synchronous spawning depends on four factors such as time of the year, water temperature, the tidal and lunar cycles. This type of spawning is also done when there is less water movement over the reef such as low tides. Asexually reproduction initiates growth of a colony by budding. Budding occurs when a portion of the parent polyp pinches off to form a new individual. Budding enable the polyp to replicate itself several times and at the same time maintain tissue connections within the colony. Later, the same polyp may reproduce sexually.
Baby coral looks like tiny jelly fish floating around in the water until they find a hard place to attach to which normally is a reef. Once this process has been completed it begins to build itself a shell which is made by combining CO2 and CA into the water to make limestone. The shell is shaped round with polyps that live inside.
In today’s society people do not realize how harmful humans are not only to our environment but to the marine life as well. Carbon is a part of the ocean air, rocks and all living things it does not stay confined to one area it is always on the move. Carbon moves from the atmosphere to the plants and then through the food chains. Animals eat plants and receive carbon and then other animals eat the plant eating animals and this is how they receive their carbon. Then the waste is also deposited into the ground which is how plant life receives their carbon. Human’s burn fossil fuel which releases carbon dioxide rapidly into the air. Humans burn fossil fuels to power their power plants, automobiles and factories. Each year billions of carbon dioxide is released by burning fossil fuels. The weight of 100 million African elephants. (Reefs&People, 2009) The carbon dioxide enters the atmosphere some is dissolved in seawater. Humans have burned so much co2 there is 30% more carbon dioxide in the air today than there was 150 yrs ago. More greenhouse gases are in our atmosphere causing our planet to become warmer.
Warming of the oceans causes coral reefs to sicken and die. Due to global warming corals have begun with what is called “Coral Bleaching” which is the algae dies in the polyps or they leave the coral either way this is what gives the coral it beautiful color. Another issue with the water warming it allows more harmful algae to grow over the corals which kill it by blocking the sunlight, without the sun the zooxanthellae cannot perform photosynthesis and soon die.
Coral Reefs are very important to peoples' lives due to the fact a lot of fisherman catch their fish from the coral reefs. This also is killing the coral reefs this could be prevented if the fisherman was careful and not to drop cages on the reef disturbing the reefs way life. Divers catch the fish that live in or around the reefs which would be ok too if they done it cautiously but normally divers are not educated on the habitat of a reef or on how to catch fish without disrupting the remaining habitat. They do whatever it takes to catch all the fish at once. Most divers put explosive into the reefs and once it blows up they use a net to catch all the stunned fish swimming around. This kills the plants, animals and for those who do survive homeless. Some divers also use cyanide poison that stuns the fish but kills the corals. People study the reefs that have died by cutting into them. The reef is a lot like a tree by having the circles or lines indicating how old the tree or reef was along with the quality of life rather it was a good or bad reef. If the coral reef had wide lines it was a fruitful year or if the lines were small this meant sickness or drought. This can help study weather changes, fishing area compared the good years and bad years indicated on the reef.
People are causing harmful changes in the nitrogen cycle as well by the amount of N2 stored in the land, water, air and organisms. Most plants get nitrogen they need to grow from the soils or water in which they live. When an organism dies, their bodies decompose bringing the nitrogen into the soil on land or into ocean water. Bacteria alter the nitrogen into a form that plants are able to use. Some people use rich nitrogen fertilizers to make their plant grow plentiful and fast. By doing this it normally ends up dying and uses up all the nitrogen in the soil so it does not replenish for other plants that animals may eat. Fertilizer runoff and untreated sewage put added nutrients to coastal ecosystems. These elevated nutrient levels promote algae growth. This could smother the coral polyps. Certain fish and invertebrates keep and maintain a certain algae balance under normal circumstances.
As mentioned before the disturbances of a reef is very harmful to the ecosystem of the coral reef. Slight changes in one component of the ecosystem can affect the health of other components. Normally the causes of the changes are either natural disturbances or anthropogenic disturbances.
The Coral reef ecosystem is naturally variable and experience natural disturbances that vary on both temporal and spatial scales. (Reefs&People,2009) natural disturbance events that affect coral reefs are tropical storms, outbreaks of coral predators, disease, extended periods of elevated or low water temperatures and extremely low tides. Although these events disturb the reefs and may kill some corals it also benefits in other ways. Hurricanes can flush out sediment that has accumulated over the years and create more substrate for another organism to grow. Normally a healthy reef can recover from a natural disturbance.
It takes time to repair ecosystem damage and if a lot of disturbances hit at once it takes longer to recover after each one. The health of the ecosystem erodes if the recovery time lingers than the time between each disturbance. Young organism from a seed source provides the basis for recovery. They invade a damage area of the reef and begin to repair ecosystem damages. Also a set of species provides more options for recovering as well.
I think everyone should be aware of how important coral reefs are to us as humans and how important it is to be educated on how to cautiously fish and care for things that provide for us. Without this ecosystem for ours we would be in for a major disaster. The reefs supply millions with food and other resources, this ecosystem is facing greater rates of disturbances due to our actions and too much disturbance reduces the productivity, diversity and resilience of the coral reef ecosystem and preserving this ecosystem will rely largely on preserving the habitats and species of the coral reef ecosystem.

References
Best, B., & Bornbusch , A. (2001). Coral reefs in crisis. Washington, DC: American Association for the Advancement of Science. DOI: www.aaas.org
Bruce, S. (2008, July 10). Reef building corals face extinction. Retrieved from http://www.sci.odu.edu/gmsa/about/corals.shtml (2009). Reefs & people: What is at stake. Washington, DC: DOI: www.wri.org