This is why corals don’t live in areas where rivers drain fresh water into the ocean (“estuaries”). 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. Subscribe to our newsletter and never miss an important update! Most reefs recovered, with low levels of coral deaths, but damage has been severe at places. ( Log Out /  The Great Barrier Reef is the world’s largest coral reef system composed of over 2,900 individual reefs and 900 islands. The relationship between corals and photosynthetic algae living inside their tissues is the best example of mutualism. Posted on 05/22/2020 05/22/2020 by apho2018. It is stretched for over 2,300 kilometres over an area of approximately 344,400 square kilometres. 2 Year Validity == Validity of the Download links (both Static & Current Affairs) is 2 Years from the date of purchase. 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. 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Savindra Singh [Amazon and Flipkart], Filed Under: Geography, Oceanography, Physical Geography, Your email address will not be published. They are an integral part of many cultures and our natural heritage. Kutch Region (Gujarat) Gulf of Mannar; Lakshadweep islands. Coral reefs need clean water to thrive. From litter to waste oil, pollution is damaging reefs worldwide. The temperature of the water should not be below 20°C. Conditions Required for Healthy Growth of Coral Reef. Recent research has revealed that corals that are consistently exposed to low levels of stress may develop some kind of resistance to bleaching. Therefore, some reefs form over several million years (Veron, 2000). not falling below 20*C approx. Coral Reefs in India. In UPSC mains exam, question demanding a direct explanation and importance of a particular geographic entity/ phenomena are commonly asked. 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 … 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. The corals in Puerto Rico and Hawaii were in good condition. Disturbances affecting coral reefs include anthropogenic and natural events. The condition virtually limits the areal distribution of corals to the tropical, and sub-tropical zones. After years of campaigning, many countries are now changing policy; banning plastic bags, straws and single-use plastic packaging. Required fields are marked *, Copyright © 2016-20 Pmfias.com. 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 corals receive their coloration from the ZOOXANTHELLAE living within their tissues. Reefs act as natural barriers to shorelines, protecting them from the effects of moving water. The coral reef are natural barriers to storm surges, particularly in regions that are susceptible to hurricanes. Importance of Corals The temperature should not exceed 35°C. Recent accelerated coral reef decline is related mostly to anthropogenic impacts, Natural disturbances which cause damage to coral reefs include. 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. Zooxanthellae live symbiotically within the polyps. Suitable Conditions for Coral Growth These algae use the carbon dioxide produced by the polyps to conduct photosynthesis. Rather than causing coral reef bleaching, an increase in ambient elemental nutrient concentrations (e.g. When coral polyps are too hot, they expel their zooxanthellae. Your email address will not be published. Though warm waters as a result of global warming results in coral bleaching, it could be offset by diversity the algae renders to corals. Coral sand is one main player. ( Log Out /  Coral reefs are huge deposits made up dead shells and secretions of marine organisms like Corals, Calcarious algae, stomatopteroids, gartopods Mollusca etc. When corals are exposed to high concentrations of chemical contaminants like copper, herbicides and oil, coral bleaching happens. Corals need saltwater to survive and require a certain balance in the ratio of salt to water. In turn zooxanthellae are responsible for the colors and diversity of them to polyps. 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). It is stretched for over 2,300 kilometres over an area of approximately 344,400 square kilometres. On these skeletons, other corals grow. This document is highly rated by UPSC students and has been viewed 3 times. Fill in your details below or click an icon to log in: You are commenting using your WordPress.com account. The tissues of corals themselves are actually not the beautiful colors of the coral reef, but are instead clear. This video is highly rated by UPSC students and has been viewed 1 times. 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. Sediment and plankton can cloud water, which decreases the amount of sunlight that reaches the zooxanthellae. Physical damage to the coral reefs can occur through contact from careless swimmers, divers, and poorly placed boat anchors. 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. A species interaction in which both species benefit from the interaction is called as mutualism. 1. not falling below 20*C approx. All rights reserved | Terms & Privacy | Amazon Affiliate Disclosure. ( Log Out /  The polyps extract calcium salts from sea water to form these hard skeletons. The issue is related to GS-1 syllabus under the following heading- Salient features of world’s physical geography. 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. As these corals grow and die, they leave behind their calcium carbonate skeletons. Corals need clear water that lets sunlight through; they don’t thrive well when the water is opaque. The water temperature … Ocean Acidification: Due to rise in carbon dioxide levels, oceans absorb more carbon dioxide. The third global coral bleaching is in progress (2015-16) — after events in 1998 and 2010. It also encourages the growth of algae, which compete with corals for space on the reef. 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. Growing corals is a delicate balance – restoring our reefs without presenting more unnatural materials into our oceans. Published on 19-Sept-2019 – Coral Reefs. Many discarded plastic is broken down into what is known as microplastics, tiny pieces that are mistaken by coral polyps as food and ingested. Fishing with dynamite, cyanide and other damaging methods can damage entire reefs and is 100% unsustainable. Conditions for Growth of Coral Reefs 1. The reef is located in the Coral Sea, off the coast of Queensland, Australia. Geography for UPSC Civil Service Exam – Overview Of Coral Reefs. Coral reefs are large underwater structures composed of the skeletons of coral, which are marine invertebrate animals. the question wants us to describe the ideal environmental conditions for growth of coral reefs and then … Corals rarely develop in water deeper than 165 feet (50 meters). About Great Barrier Reef. The temperature should not exceed 35°C. This explains why coral reefs are generally absent on western coast of the continent. They support fish stocks on which some 500 million people are dependent globally. Dec 13, 2020 - Types of Coral Reefs UPSC Video | EduRev is made by best teachers of UPSC. Rapid dilution of reef waters from storm-generated precipitation and runoff has been demonstrated to cause coral reef bleaching. Different corals living in different regions can withstand various temperature fluctuations. Corals can survive only under saline conditions with an average salinity between 27% to 40%. 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. To watch all lessons click here:- | Download the Unacademy Learning App from the . Serwis dla słuchowców, tworzony z pasją, na którym nauczysz się języka angielskiego online inaczej niż w szkole. As coral reefs die, coastlines become more susceptible to damage and flooding from storms, hurricanes, and cyclones. This course explains coral reefs for the exam UPSC CSE. & does not flourish in cold currents. The reef is located in the Coral Sea, off the coast of Queensland, Australia. Copyright © 2016-20 Pmfias.com. This increases the acidity of ocean water and inhibits the corals ability to create calcareous skeletons, which is essential for their survival. 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. Sale! ; Coral reefs on India’s east coast are making a comeback. But rising temperatures mean reduction in the concentration of these UV absorbing compounds in corals. Sensitive habitats can be destroyed or disturbed by the dredging of deep-water channels or marinas, and through the dumping of waste materials. 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. The coral and the associated organisms and algae, which are the most common reef builders are confined to the tropical belt. The most favourable temperature for the growth of the coral reefs is between 23°C to 25°C. 1 Year Validity == Validity of the Download links (both Static & Current Affairs) is 1 Year from the date of purchase. Change ), You are commenting using your Twitter account. Sediment can create cloudy water and be deposited on corals, blocking out the sun and harming the polyps. 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. 22 May. Corals generally live in water temperatures of 20–32° C. Corals are sensitive to pollution and sediments. Warm water temperature: Reef-building corals require warm water conditions to survive. Sediment and plankton can cloud water, which decreases the amount of sunlight that reaches the zooxanthellae. As a rule they thrive well only in warmer tropical seas, with water temp. Coral reefs are the skeletons of stony coral polyps cemented together. The reef is located in the Coral Sea, off the coast of Queensland, Australia. In contrast, many of the coral bleaching events observed in the 1980s occurred over large geographic regions and at all depths. Coral bleaching has occurred mostly during the summer seasons or near the end of a protracted warming period. Polyps are shallow water organisms which have a soft body covered by a calcareous skeleton. Coral reefs’ unexpected comeback. 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. If zooxanthellae loss is prolonged, i.e. if the stress continues and depleted zooxanthellae populations do not recover, the coral host eventually dies . 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. & does not flourish in cold currents. The deposits are mostly made up of Calcium Carbonate. The zooxanthellae return to the polyps when the water cools, but repeated bleaching events lead to the death of the coral polyps. Corals need to grow in shallow water where sunlight can reach them. It will impact marine ecosystem, as coral reefs are some of the most bio diverse and productive ecosystems. Favourable conditions for Coral Reefs. Corals grow very slowly - some grow only about 3-20mm per year. At the beach, don't purchase souvenirs that have been taken from the reef, such as coral jewelry, or live fish from the reef. Bleaching happens when the densities of zooxanthellae decline or when the concentration of photosynthetic pigments within the zooxanthellae fall. You will be learning about the conditions for growth, formation, bleaching and world distribution. Apart from these areas, they are also found in some areas of Maharashtra and Karnataka. Fringing Reef. Coral bleaching has occurred mostly during the summer seasons or near the end of a protracted warming period. UPSC Civil Services Examination UPSC Notes GS-I [Geography] Topic: Coral Reefs ... Growth conditions for Coral Reefs 1. Some reefs are even older than our old-growth redwood forests. 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. Change ), You are commenting using your Facebook account. They are reported to have taken place during times of. Corals need to grow in shallow water where sunlight can reach them. 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. This explains why coral reefs are generally absent on western coast of the continent. Significance. Each individual coral is referred to as a polyp. Because of Cold Ocean Currents – corals like warm waters and hate cold waters]. The corals actually contain UV-absorbing compounds which can block potentially damaging UV radiation. Coral reefs are large underwater structures composed of the skeletons of coral, which are marine invertebrate animals. Remember to never fish or boat near a reef, and don't litter on the beach or in the ocean. They use the traditional cnidarian strategy of capturing tiny planktonic organisms with their tentacles (All about Phylum Cnidaria is given in NCERT). This hard surface is a precondition for compaction, cementation and solidification of unconsolidated skeletons of Coral Polyps. ( Log Out /  8 million tones of plastic rubbish enters the world’s oceans every single year. Over-fishing of certain species on or adjacent to coral reefs can affect the reef’s ecological balance and biodiversity. They are found in following areas in a major way in India: Andaman and Nicobar Islands (the highest coral reef area in India). Key demand of the question. 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. 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. Coral polyps can obtain most of their nutrition from algae, called zooxanthellae. The underwater tiny organism polyps form the coral reefs. 2. Change ), You are commenting using your Google account. About Great Barrier Reef . Today, these important habitats are threatened by a range of human activities. #ias2020 #UPSC #environment In this lecture, we discuss Environment & Ecology for UPSC CSE Prelims and Mains Examination by ADITI SHARMA … 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. Bleaching events occur during sudden temperature drops accompanying intense upwelling episodes [El-Nino], seasonal cold-air 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. 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. Conditions required for … 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. Coral reefs are being degraded by an accumulation of stresses arising from anthropogenic activities and changes in the natural environment. Coral Reefs are differentiated into three categories based on their shape, nature and mode of occurrence. Will be Learning about the conditions for growth, formation, bleaching and world distribution fishing tourism. Sunlight through ; they don ’ t live in areas where rivers drain fresh water into the ocean but! 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