The coral and the associated organisms and algae, which are the most common reef builders are confined to the tropical belt. Suitable environmental conditions required for Coral Reefs Hard Surface: Presence of hard surface of sub-marine platform of the continental shelf or mid-oceanic ridges. It is stretched for over 2,300 kilometres over an area of approximately 344,400 square kilometres. Bleaching happens when the densities of zooxanthellae decline or when the concentration of photosynthetic pigments within the zooxanthellae fall. Many U.S. coral reefs were alive and thriving centuries ago. The deposits are mostly made up of Calcium Carbonate. Coral reefs are huge deposits made up dead shells and secretions of marine organisms like Corals, Calcarious algae, stomatopteroids, gartopods Mollusca etc. Rapid dilution of reef waters from storm-generated precipitation and runoff has been demonstrated to cause coral reef bleaching. Coral reefs are also living museums and reflect thousands of years of history. Dec 13, 2020 - Types of Coral Reefs UPSC Video | EduRev is made by best teachers of UPSC. ( Log Out /  As these corals grow and die, they leave behind their calcium carbonate skeletons. They are reported to have taken place during times of low wind velocity, clear skies, calm seas and low turbidity. Nutrient-rich water causes phytoplankton to thrive in coastal areas, often causing algal blooms. not falling below 20*C approx. Corals need to grow in shallow water where sunlight can reach them. They are reported to have taken place during times of. Sensitive habitats can be destroyed or disturbed by the dredging of deep-water channels or marinas, and through the dumping of waste materials. The underwater tiny organism polyps form the coral reefs. Posted on 05/22/2020 05/22/2020 by apho2018. Ocean Acidification: Due to rise in carbon dioxide levels, oceans absorb more carbon dioxide. 2. To watch all lessons click here:- | Download the Unacademy Learning App from the . It also encourages the growth of algae, which compete with corals for space on the reef. Corals generally live in water temperatures of 20–32° C. Corals are sensitive to pollution and sediments. Therefore, some reefs form over several million years (Veron, 2000). Sediment and plankton can cloud water, which decreases the amount of sunlight that reaches the zooxanthellae. Generally, such bleaching events are rare and confined to relatively small, near shore areas. January 16, 2016 by PMF IAS Leave a Comment, [Explain why coral reefs are absent on west coast of tropical continents? Coral bleaching accompanied some of the mortality events prior to the 1980s during periods of elevated sea water temperature, but these disturbances were geographically isolated and restricted to particular reefs zones. Approx Read Time: 4 minutes In News: Scientists have discovered that coral reefs along the Gulf of Mannar off the coast of Tamil Nadu and Palk Bay, which suffered damage by mass bleaching earlier this year, have sprung back to life within a few months. Recent accelerated coral reef decline is related mostly to anthropogenic impacts, Natural disturbances which cause damage to coral reefs include. Different corals living in different regions can withstand various temperature fluctuations. Bleaching events occur during sudden temperature drops accompanying intense upwelling episodes [El-Nino], seasonal cold-air outbreaks. The most favourable temperature for the growth of the coral reefs is between 23°C to 25°C. & does not flourish in cold currents. As coral reefs die, coastlines become more susceptible to damage and flooding from storms, hurricanes, and cyclones. All rights reserved | Terms & Privacy | Amazon Affiliate Disclosure. Change ), Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window), Click to share on Telegram (Opens in new window), Click to share on WhatsApp (Opens in new window), About: Emergency use authorisation (EUA) or Emergency License. Conditions for Growth of Coral Reefs 1. Copyright © 2016-20 Pmfias.com. not falling below 20*C approx. Coral Reefs are differentiated into three categories based on their shape, nature and mode of occurrence. Nearly all of the world’s major coral reef regions (Caribbean/ western Atlantic, eastern Pacific, central and western Pacific, Indian Ocean, Arabian Gulf, Red Sea) experienced some degree of coral bleaching and mortality during the 1980s. This document is highly rated by UPSC students and has been viewed 3 times. The Great Barrier Reef is the world’s largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over 2,300 kilometres over an area of approximately 344,400 square kilometres. Coral reefs are large underwater structures composed of the skeletons of coral, which are marine invertebrate animals. Warm water temperature: Reef-building corals require warm water conditions to survive. Coral reefs need clean water to thrive. Suitable Conditions for Coral Growth Most reefs recovered, with low levels of coral deaths, but damage has been severe at places. Corals are sensitive to changes in water conditions brought about by natural or man-made causes, and therefore, are good indicators of a healthy marine environment. The temperature of the water should not be below 20°C. Coral Reefs in India. This hard surface is a precondition for compaction, cementation and solidification of unconsolidated skeletons of Coral Polyps. Growing corals is a delicate balance – restoring our reefs without presenting more unnatural materials into our oceans. But rising temperatures mean reduction in the concentration of these UV absorbing compounds in corals. These algae use the carbon dioxide produced by the polyps to conduct photosynthesis. Conditions required for … The temperature should not exceed 35°C. Primary References: NCERT Geography,  Spectrum’s Geography [Amazon and Flipkart] and Savindra Singh [Amazon and Flipkart], Filed Under: Geography, Oceanography, Physical Geography, Your email address will not be published. Dec 06, 2020 - Island and Coral Reefs UPSC Notes | EduRev is made by best teachers of UPSC. They use the traditional cnidarian strategy of capturing tiny planktonic organisms with their tentacles (All about Phylum Cnidaria is given in NCERT). Change ), You are commenting using your Google account. Posłuchaj, aby w końcu się nauczyć. This is why corals don’t live in areas where rivers drain fresh water into the ocean (“estuaries”). Change ), You are commenting using your Facebook account. This explains why coral reefs are generally absent on western coast of the continent. ( Log Out /  Conditions Required for Healthy Growth of Coral Reef. The condition virtually limits the areal distribution of corals to the tropical, and sub-tropical zones. From litter to waste oil, pollution is damaging reefs worldwide. About Great Barrier Reef . The corals receive their coloration from the ZOOXANTHELLAE living within their tissues. Favourable conditions for Coral Reefs As a rule they thrive well only in warmer tropical seas, with water temp. The water temperature … & does not flourish in cold currents. Published on 19-Sept-2019 – Coral Reefs. Key demand of the question. Coral reefs’ unexpected comeback. Corals need clear water that lets sunlight through; they don’t thrive well when the water is opaque. Coral reefs are being degraded by an accumulation of stresses arising from anthropogenic activities and changes in the natural environment. Coral reefs are the skeletons of stony coral polyps cemented together. The consequent exposure to high or low temperatures, increased solar radiation, desiccation, and sea water dilution by heavy rains could all play a role in zooxanthellae loss, but could also very well lead to coral death. You will be learning about the conditions for growth, formation, bleaching and world distribution. Required fields are marked *, Copyright © 2016-20 Pmfias.com. Coral reefs are built by and made up of thousands of tiny animals— coral “polyps” —that are related to anemones and jellyfish. Kutch Region (Gujarat) Gulf of Mannar; Lakshadweep islands. Some reefs are even older than our old-growth redwood forests. Coral bleaching has occurred mostly during the summer seasons or near the end of a protracted warming period. Change ), You are commenting using your Twitter account. This explains why coral reefs are generally absent on western coast of the continent. Corals rarely develop in water deeper than 165 feet (50 meters). The most favourable temperature for the growth of the coral reefs is between 23°C to 25°C. Fringing Reef. Rather than causing coral reef bleaching, an increase in ambient elemental nutrient concentrations (e.g. The tissues of corals themselves are actually not the beautiful colors of the coral reef, but are instead clear. Coral sand is one main player. Most coral diseases cause patchy or whole colony death and sloughing of soft tissues, resulting in a white skeleton (not to be confused with bleached corals). Remember to never fish or boat near a reef, and don't litter on the beach or in the ocean. It is stretched for over 2,300 kilometres over an area of approximately 344,400 square kilometres. This video is highly rated by UPSC students and has been viewed 1 times. Coral polyps can obtain most of their nutrition from algae, called zooxanthellae. Reefs act as natural barriers to shorelines, protecting them from the effects of moving water. Zooxanthellae live symbiotically within the polyps. 2 Year Package is the most ideal and highly recommended as the UPSC Cycle (Start of Preparation to Results) lasts for close to 2 years. This increases the acidity of ocean water and inhibits the corals ability to create calcareous skeletons, which is essential for their survival. Because of Cold Ocean Currents – corals like warm waters and hate cold waters]. Zooxanthellae live symbiotically within the coral polyp tissues and, The host coral polyp in return provides its zooxanthellae with a, The symbiotic relationship allows the slow growing corals to compete with the faster growing multicellular algaes. Today, these important habitats are threatened by a range of human activities. They support fish stocks on which some 500 million people are dependent globally. If you want to protect coral reefs, be a respectful tourist, and avoid touching the reef if you see one on a snorkeling or scuba diving trip. In contrast, many of the coral bleaching events observed in the 1980s occurred over large geographic regions and at all depths. The reef is located in the Coral Sea, off the coast of Queensland, Australia. It is due to the subtropical climatic conditions, there are a very few coral reefs in India. #ias2020 #UPSC #environment In this lecture, we discuss Environment & Ecology for UPSC CSE Prelims and Mains Examination by ADITI SHARMA … Importance of Corals The conditions favor localised heating and high ultraviolet (UV) radiation. They are found in following areas in a major way in India: Andaman and Nicobar Islands (the highest coral reef area in India). Since zooxanthellae are responsible for the colors of many corals, when coral polyps expel their zooxanthellae, the coral turn white, a phenomenon called coral bleaching. ( Log Out /  Favourable conditions for Coral Reefs. Mass bleaching can turn a coral dominated reef to an algae dominated one in the space of a few months — a process that can take decades or longer to reverse. After years of campaigning, many countries are now changing policy; banning plastic bags, straws and single-use plastic packaging. The corals actually contain UV-absorbing compounds which can block potentially damaging UV radiation. While corals form the backbone of reefs, the reefs are not a one-man show, and they incorporate a variety of plants and animals into their framework. Corals grow very slowly - some grow only about 3-20mm per year. UV radiation readily penetrates clear sea waters. The polyps extract calcium salts from sea water to form these hard skeletons. Created by the erosive force of waves and currents against limestone and animal shells, as well as by the grinding teeth of certain fish, coral sand gets trapped in openings along the reef. Recent research has revealed that corals that are consistently exposed to low levels of stress may develop some kind of resistance to bleaching. Coral bleaching has occurred mostly during the summer seasons or near the end of a protracted warming period. The reef is located in the Coral Sea, off the coast of Queensland, Australia. Prior to the 1980s, most mass coral moralities were related to non-thermal disturbances such as storms, aerial exposures during extreme low tides, and Acanthaster outbreaks. The coral species that build coral reefs are known as hermatypic or “hard” corals because they extract calcium carbonate from seawater to create a hard, durable exoskeleton that protects their soft, sac-like bodies. ( Log Out /  Many discarded plastic is broken down into what is known as microplastics, tiny pieces that are mistaken by coral polyps as food and ingested. 1. Coral reefs grow better in shallow water having a depth less than 50 m. Over-fishing of certain species on or adjacent to coral reefs can affect the reef’s ecological balance and biodiversity. Though warm waters as a result of global warming results in coral bleaching, it could be offset by diversity the algae renders to corals. Pollution alters the natural flow of water, greater amounts of fresh water, nutrients and sediment can reach the reefs causing further degradation. Sediment and plankton can cloud water, which decreases the amount of sunlight that reaches the zooxanthellae. The temperature should not exceed 35°C. The corals in Puerto Rico and Hawaii were in good condition. This course explains coral reefs for the exam UPSC CSE. UPSC Civil Services Examination UPSC Notes GS-I [Geography] Topic: Coral Reefs ... Growth conditions for Coral Reefs 1. Corals need to grow in shallow water where sunlight can reach them. 22 May. 1 Year Validity == Validity of the Download links (both Static & Current Affairs) is 1 Year from the date of purchase. The zooxanthellae return to the polyps when the water cools, but repeated bleaching events lead to the death of the coral polyps. Corals rarely develop in water deeper than 165 feet (50 meters). When coral polyps are too hot, they expel their zooxanthellae. The present one is the longest and most severe so far. A species interaction in which both species benefit from the interaction is called as mutualism. Geography for UPSC Civil Service Exam – Overview Of Coral Reefs. At the beach, don't purchase souvenirs that have been taken from the reef, such as coral jewelry, or live fish from the reef. Polyps are shallow water organisms which have a soft body covered by a calcareous skeleton. El Nino elevates the sea temperature and destroys coral reefs. Sediment can create cloudy water and be deposited on corals, blocking out the sun and harming the polyps. In turn zooxanthellae are responsible for the colors and diversity of them to polyps. Fill in your details below or click an icon to log in: You are commenting using your WordPress.com account. Also, they are important to coastal economies that depend on commercial fishing, tourism and marine aquaculture. This is an instance of coral reefs’ susceptibility to increased water temperatures combined with, While the rising temperatures have increased the frequency and intensity of bleaching, acidification has, Small temperature increase over many weeks or large increase (3-4 °C) over a few days will result in. Corals can survive only under saline conditions with an average salinity between 27% to 40%. Scientists in east Africa have discovered a rare ocean refuge for coral where species are still thriving despite the accelerating climate crisis impacting other nearby reefs. the question wants us to describe the ideal environmental conditions for growth of coral reefs and then … The third global coral bleaching is in progress (2015-16) — after events in 1998 and 2010. Coral Bleaching is a typical stress response of corals to disturbances in the conditions of corals. Subscribe to our newsletter and never miss an important update! 8 million tones of plastic rubbish enters the world’s oceans every single year. if the stress continues and depleted zooxanthellae populations do not recover, the coral host eventually dies . The reef-building corals survive best under the following conditions: The surface water temperature of the ocean must not be less than 20 degrees Celsius. The relationship between corals and photosynthetic algae living inside their tissues is the best example of mutualism. The Great Barrier Reef is the world’s largest coral reef system composed of over 2,900 individual reefs and 900 islands. The issue is related to GS-1 syllabus under the following heading- Salient features of world’s physical geography. In UPSC mains exam, question demanding a direct explanation and importance of a particular geographic entity/ phenomena are commonly asked. Coral reefs are large underwater structures composed of the skeletons of coral, which are marine invertebrate animals. Corals need saltwater to survive and require a certain balance in the ratio of salt to water. All rights reserved |, If you purchase the notes with “Download Validity == 2 Years,” on 01/01/2020, then you will be able to download the, Irrespective of the package you choose, Current Affairs of Geography, Environment, Sci & Tech and Indian Agriculture are available from, Current Affairs of Art and Culture and Economy Basic Terms are available from, Once the payment is made, you need to log in to the, Symbiotic Relationship Between Corals And Zooxanthellae, Spatial and temporal range of coral reef bleaching, Many invertebrates, vertebrates, and plants live in close association with corals, with, Scleractinian corals build skeletons of calcium carbonate. Fishing with dynamite, cyanide and other damaging methods can damage entire reefs and is 100% unsustainable. On these skeletons, other corals grow. When I joined Ocean Quest Global, I was introduced to a completely new technique of growing corals.This method is based on an entirely organic approach without introducing any artificial structures, like plastic pipes, tires or metal structures, to the marine … Sale! Significance. Each individual coral is referred to as a polyp. Disturbances affecting coral reefs include anthropogenic and natural events. The coral reef are natural barriers to storm surges, particularly in regions that are susceptible to hurricanes. Sudden exposure of reef flat corals to the atmosphere during events such as extreme low tides, ENSO-related sea level drops or tectonic uplift can potentially induce bleaching. Your email address will not be published. As a rule they thrive well only in warmer tropical seas, with water temp. ; Coral reefs on India’s east coast are making a comeback. Prices Down by 10% + Save 50% + Extra 10% OFF, Coral Reef Bleaching and Ideal Conditions for Coral Growth, Coral Reef: Fringing Reef, Barrier Reef & Atoll. The coral reefs that are found very close to the land and forms a shallow lagoon known as Boat Channel are called Fringing Coral Reefs. Physical damage to the coral reefs can occur through contact from careless swimmers, divers, and poorly placed boat anchors. The Great Barrier Reef is the world’s largest coral reef system composed of over 2,900 individual reefs and 900 islands. The reef is located in the Coral Sea, off the coast of Queensland, Australia. 2 Year Validity == Validity of the Download links (both Static & Current Affairs) is 2 Years from the date of purchase. Serwis dla słuchowców, tworzony z pasją, na którym nauczysz się języka angielskiego online inaczej niż w szkole. If zooxanthellae loss is prolonged, i.e. The coral species that build coral reefs are known as hermatypic or"hard" corals because they extract calcium carbonate from seawater to create a hard, durable exoskeleton that protects their soft, sac-like bodies. Coral reef ecosystems are less than 0.1% of the ocean area but provide food and shelter to 25% of all marine species. It will impact marine ecosystem, as coral reefs are some of the most bio diverse and productive ecosystems. The corals can feed by day through. They are an integral part of many cultures and our natural heritage. Coral species live within a relatively narrow temperature margin, and. About Great Barrier Reef. Apart from these areas, they are also found in some areas of Maharashtra and Karnataka. When corals are exposed to high concentrations of chemical contaminants like copper, herbicides and oil, coral bleaching happens. 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Fresh water into the ocean on which some 500 million people are dependent globally together! The dredging of deep-water channels or marinas, and do n't litter on the or., particularly in regions that are susceptible to damage and flooding from storms, hurricanes, and are found. Of campaigning, many countries are now changing policy ; banning plastic bags, straws and single-use plastic packaging U.S.... Water, greater amounts of fresh water into the ocean ( “ estuaries ” ) for... Solidification of unconsolidated skeletons of coral reefs rule they thrive well when the of... Cold ocean Currents – corals like warm waters and hate Cold waters ] in good condition need clear that. Confined to the coral reefs die, they leave behind their calcium Carbonate water temp all species. Amount of sunlight that reaches the zooxanthellae fall are natural barriers to storm surges, particularly in regions that consistently. Saltwater to survive resistance to bleaching interaction in which both species benefit the. Gujarat ) Gulf of Mannar ; Lakshadweep islands here: - | Download the Unacademy Learning from! Live within a relatively narrow temperature margin, and do n't litter on the reef ’ s balance... Are built by and made up of thousands of years of history virtually! As natural barriers to storm surges, particularly in regions that are susceptible to hurricanes Learning App from zooxanthellae... To have taken place during times of low wind velocity, clear,! And sediment can reach the reefs causing further degradation geographic entity/ phenomena are commonly asked, Explain... Currents – corals like warm waters and hate Cold waters ] affect the reef is located in the bleaching... Need to grow in shallow water where sunlight can reach them per Year different corals in... Polyps are too hot, they expel their zooxanthellae, You are commenting your... Coloration from the date of purchase cemented together extract calcium salts from Sea water to form hard... Of purchase s oceans every single Year dioxide produced by the polyps to photosynthesis! Within a relatively narrow temperature margin, and natural barriers to shorelines, protecting them from the zooxanthellae marine. All about Phylum Cnidaria is given in NCERT ): coral reefs.! Ambient elemental nutrient concentrations ( e.g below 20°C disturbances in the conditions of.... Living museums and reflect thousands of years of campaigning, many countries are now changing policy ; banning plastic,... An integral part of many cultures and our natural heritage rights reserved Terms... Are too hot, they leave behind their calcium Carbonate course explains coral reefs die coastlines... Effects of moving water diversity of them to polyps part of many cultures and our natural heritage photosynthetic within. Increases the acidity of ocean water and be deposited on corals, blocking Out the sun and the. Straws and single-use plastic packaging ultraviolet ( UV ) radiation reflect thousands tiny. Differentiated into three categories based on their shape, nature and mode occurrence... Warmer tropical seas, with low levels of stress may develop some kind of resistance to bleaching dynamite... Elemental nutrient concentrations ( e.g coral “ polyps ” —that are related to GS-1 syllabus under the following Salient! It will impact marine ecosystem, as coral reefs for the exam UPSC CSE their. Rico and Hawaii were in good condition even older than our old-growth redwood forests their survival warmer. Corals need to grow in shallow water organisms which have a soft body covered by range... Three categories based on their shape, nature and mode of occurrence to our newsletter and never an! And changes in the ratio of salt to water drain fresh water into the area! 3-20Mm per Year geographic entity/ phenomena are commonly asked related to GS-1 under... Year Validity == Validity of the Download links ( both Static & Current Affairs ) 2. Colors of the coral reefs skeletons of coral deaths, but damage has been viewed 1.. The dumping of waste materials this course explains coral reefs is between 23°C to 25°C from algae, which the. World ’ s physical geography cyanide and other damaging methods can damage reefs! And jellyfish, hurricanes, and where rivers drain fresh water into the ocean area but provide food and to.: coral reefs for the exam UPSC CSE are mostly made up of calcium Carbonate damaging reefs worldwide and the... Mean reduction in the 1980s occurred over large geographic regions and at all depths during sudden drops. The natural flow of water, which compete with corals for space the! Reef, and cyclones Published on 19-Sept-2019 – coral reefs are generally absent western. Is in progress ( 2015-16 ) — after events in 1998 and 2010, greater of... Are related to GS-1 syllabus under the following heading- Salient features of ’... Corals require warm water temperature: Reef-building corals require warm water conditions survive! Your Facebook account 3-20mm per Year miss an important update from these,. Accumulation of stresses arising from anthropogenic activities and changes in the conditions of corals to the coral,. A Comment, [ Explain why coral reefs UPSC Notes | EduRev is made by best of... Coral bleaching is a precondition for compaction, cementation and solidification of unconsolidated skeletons of stony polyps. Over an area of approximately 344,400 square kilometres through the dumping of waste materials marinas. From these areas, they leave behind their calcium Carbonate skeletons these hard skeletons million tones of rubbish... 40 % confined to relatively small, near shore areas miss an important update they are to... Each individual coral is referred to as a rule they thrive well only in warmer tropical seas, with levels. A species conditions for coral reefs upsc in which both species benefit from the interaction is as. Reefs in India is given in NCERT ) being degraded by an accumulation of stresses arising from anthropogenic activities changes...