Structural Biology and Its Importance to Humans and the Environment - Essay Example

Coral Reefs- Structural Biology and its importance to Humans and Environment Coral reefs have the unique distinction of being the largest structuresof biological origin on earth. This is due to the fact that these reef forms were actually ancient animals which evolved over the last millions of years. Corals belong to the class of anthozoans in the phylum Cnidaria, which includes about 6000 known species (National Oceanic and Atmospheric Administration, 2010). They are one of the most densest and varied ecosystems and cover about 0.2% of the ocean floor and offer enormous benefits to both environment and mankind. However the recent manmade and natural calamities have caused serious damage to the coral reef structures and as a result many reef formations have been lost over the years. Hence environmentalists and especially those in the field of marine biology are relentlessly trying to put an end to the destruction of coral reefs (Weir, 2001; Shah, 2010; Skoloff, 2010 Skoloff, 2010). All corals have a simple basic structure which is referred to as a polyp that consists of three layers of tissue: an outer epidermis, an inner cell layer surrounding the gastrovascular cavity and a middle layer of mesoglea. The gastrovascular cavity opens only at one end which facilitates food intake by the organism and also waste products are expelled through the same. Corals also possess tentacles which project as extensions of the body wall in the regions surrounding the mouth which mainly help to capture and ingest food as well as a source of defense when needed. In addition to this the presence of a unique type of cell called the cnidocyte that includes organelles such as nematocysts secrete lethal toxins which are helpful in prey capture. Additionally most corals contain a symbiotic alga, zooxanthellea, within their gastrodermal cells and both the algae and the coral share a mutually beneficial relationship by supplying resources required for photosynthesis, organic products of photosynthesis and facilitating waste removal. This mutual exchange is vital for coral productivity as well as limestone-secreting capacity of the coral reefs using the photosynthetic produce of the algae. In addition, the presence of the algae is responsible for the color of the polyp and if the algae are expelled by the corals, which may occur during periods of prolonged stress, the coral reefs become while in color, a process which is referred to as coral bleaching. Using the photosynthetic products released by the algae the corals produce calcium carbonate. Of the 6000 known species of anthozoans, stony corals make up the majority and they are responsible for laying the foundations of the reef structures during the development of the coral reefs. The calcium carbonate skeletons secreted by the stony corals gets deposited in the lower portion of the polyp, and the process produces a cup referred to as a calyx. The polyps secrete calcium carbonate at regular intervals which elevates the coral. When polyps are part of coral colonies they are connected to the neighboring polyp through a thin tissue called the coenosarc above the skeleton structure (National Oceanic and Atmospheric Administration, 2010; Weir, 2001). Coral colonies exist in different shapes and about 10 forms have been classified which includes branching, digitate, table, encrusting etc. The shape taken depends on several factors such as the coral species, location and environment. Environmental factors such as sunlight also affect the rate at which the colonies grow as when exposed to bright sunlight the calcification process is almost doubled. As the formation of adequate amounts of limestone is critical for reef formation, coral colonies require consistent environmental conditions such as temperature range between 18 to 29 degrees Celsius, show optimum growth in salted, clear and nutrient-free water which allow good penetration of sunlight (National Oceanic and Atmospheric Administration, 2010; Weir, 2001). Hence the coral reefs are also vulnerable to certain environmental conditions (Weir, 2001). Presence of sediments that cover the coral colonies can disrupt its ability to harness sunlight and also impair their feeding. Thus under conditions of cold and dense water the coral reefs lose their ability to produce the required quantity of limestone thus restricting their growth to tropical and semitropical regions and at lower latitudes (National Oceanic and Atmospheric Administration, 2010).Coral reefs form when pieces of coral larvae attach themselves to submerged edges of islands or continents. As they develop the reefs may take three types of structures: fringing reefs that form directly from the shore and borders the shoreline, barrier reefs which are separated from the land by deep waters and atolls which take a circular form with a lagoon in the center (National Oceanic and Atmospheric Administration, 2010). The presence of coral reefs help to protect shores from storms and most importantly they play a vital role in the formation of the ocean food chain as accoriding to scientific reports nearly 1 million species of fishes and invertebrates thrive in these reefs (Weir, 2001). Apart from animals, billions of humans also depend on corals for their food as well as livelihood (Weir, 2001; Shah, 2010; Skoloff, 2010). However, the past years have witnessed the slow destruction of the coral reef structures across the world which is mainly due to unhealthy activities such as bomb and dynamite fishing, development of the coastal areas, rising levels of carbon dioxide in the atmosphere due to pollution has caused acidification of the oceans and global warming all of which has affected the basic foundations of the reef structures thus leading to their destruction (Weir, 2001; Shah, 2010). According to latest reports nearly 19% of the world’s reef structure has already been destroyed and researchers believe that if the present circumstance prevails another 15% may be lost within he next 20 years and in about 100 years the entire coral reef habitat could become extinct (Skoloff, 2010). A report from the World resources Institute has stated that nearly 58% of reefs are threatened by human developments with nearly half a billion people living within a radius of fifty miles from the reef. In places like Florida there have been reports that household wastes are directly drained in to the ocean which settle on the polyps thus preventing the penetration of sunlight (Weir, 2001; Shah, 2010). Global warming and its subsequent effect on sea temperature has resulted in coral bleaching by which the corals become white in color due to loss of polyps and the excess carbon dioxide released in to the atmosphere is being absorbed by oceans which has led to its acidification (Shah, 2010). The Great Barrier Reef which is one of the best managed coral ecosystems is also facing major threats from natural and man-related activities such as illegal fishing (Shah, 2010). While coral reefs have the natural ability to recover when hit by natural calamities such as hurricanes due to their adaptation to such situations, the damages that are being cause due climatic and man-related activities are having a permanent impact on the growth and health of the reefs (Weir, 2001). Several propositions have been introduced to save the coral from destruction. Environmentalists are campaigning for cutting carbon emissions in to the atmosphere to control global warming (Skoloff, 2010). However, in one of the studies carried out by biologist Steve Palumbi showed that corals that were growing in shallow lagoons were able to withstand high temperatures for up to 6 days. However, his study was limited to a particular species and duration. Further research needs to be done to ascertain similar abilities in other coral species and for greater lengths of time. In another study, Palumbi compared smaller and larger marine protected areas and found that while the species present in smaller protected areas increased fish productivity, those growing in wide stretches of protected oceans had better chances of spreading. However, while the smaller areas are easy to manage they suffer from the risk of illegal fishing activities and larger areas are difficult to maintain and are associated with several social and political issues. Thus, according to Palumbi policymakers together with the research community should design reserves in a manner that would benefit both humans as well as the coral population (Science Daily, 2010). In order to protect the coral species many marine reserve areas have been classified as no-take zone, which implies nothing can be taken from that area including fish. Such impositions are being opposed by fisherman whose livelihood depends on fishing. Hence it has become pertinent that the right policies need to be framed in order to strike balance between species preservation and catering to human needs (Skoloff, 2010; Science Daily, 2010). In order to monitor the growth and health of reefs several reef monitoring programs have been set up such as the Global Reef Monitoring Network in which volunteers assess the health of coral reefs. More recently the Landsat 7 which was launched by NASA is being used to monitor shallow ocean regions and scientists have begun to map the coral reef structures around the world. Such technologies will help identify reefs that are in imminent danger and together with other programs the destruction of the reefs can be slowly reversed (Weir, 2001). Thus apart from being a shelter for several species of fishes and other organisms to thrive, coral reefs are vital for hotel and tourism industries as well as to the medical field which utilizes several species of corals to find potential cures for diseases such as cancer. Hence it is of prime importance not only for marine biologist but for governments and other institutes to protect the reefs from destruction (Skoloff, 2010). Reference 1. National Oceanic and Atmospheric Administration. 2010. About Coral Reefs. http://coris.noaa.gov/about/what_are/ [17 April 2010] 2. Weir, J. 2001. Earth Observatory. Mapping the decline of coral reefs. http://earthobservatory.nasa.gov/Features/Coral/coral.php [17 April 2010] 3. Shah, Anup. 2010. Global Issues. Coral reefs. http://www.globalissues.org/article/173/coral-reefs#globalissues-org[17 April 2010] 4. Skoloff, B. 2010. Death of coral reefs could devastate nations. The Associated press. http://www.google.com/hostednews/ap/article/ALeqM5h00FEqYmsZFmix6qyOrSXF0x2YEAD9ELQ4E83 5. Science Daily. 2010. Climate change and Coral Reefs: Coral Species has Developed the ‘Skills’ to Cope with Rising Temperatures. http://www.sciencedaily.com/releases/2010/02/100222094803.htm[17 April 2010] Read More