The Coral Reefs Ecosystem

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