Coral reefs

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Coral Reefs

description

Suitable for the GCSE geography course - post 2008.

Transcript of Coral reefs

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Coral Reefs

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Coral reefs are often referred to as the rainforests of the oceans because they are so biodiverse.

Coral reefs are warm, clear, shallow ocean habitats that are rich in life.

The reef's massive structure is formed from coral polyps, tiny animals that live in colonies; when coral polyps die, they leave behind a hard, stony, branching structure made of limestone.

The coral provides shelter for many animals in this complex habitat, including sponges, fish (e.g. blacktip reef sharks, groupers, clown fish, eels, parrotfish, snapper, and scorpion fish), jellyfish, anemones, sea stars, crustaceans (like crabs, shrimp, and lobsters), turtles, sea snakes, snails, and mollusks (like octopuses and clams). Birds also feast on coral reef animals.

CORAL REEFS

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Coral reefs develop in shallow, warm water, usually near land, and mostly in the tropics; coral prefer temperatures between 24-26 °C and depths not exceeding 25 metres so that light can penetrate. The water must also be clear and free from sediment.

There are coral reefs off the eastern coast of Africa, off the southern coast of India, in the Red Sea, and off the coasts of northeast and northwest Australia and on to Polynesia.

There are also coral reefs off the coast of Florida, the Caribbean and Brazil.

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Coral Reefs are amazingly bio-diverse - They have an enormous range of species of flora and fauna

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Coral polyps live on and in the limestone structures that make up the reef

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Fish off all kinds live from the nutrient rich seas in and around the corals

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It’s a scuba divers paradise – but the corals are extremely delicate and may be easily damaged

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What amazing colours!

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If the corals are damaged they die, nutrients decay and fish disappear

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The coral reefs are second to the tropical rainforests for the richness and variety of life

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But as said the corals are very delicate – one scuba diver’s foot on the coral and several square metres of coral die!

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The value of coral reefs

• Rich and varied ecosystem - second most diverse with 25% of the world’s fish species

• Natural barrier to wave action so creating protection to coastal settlements

• Excellent tourist attractions (scuba diving and snorkelling) creating wealth for poor communities

• Major scientific value - some believe the flora and fauna living on the reefs may hold the solution to many of the world’s diseases

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Cebu

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Trouble for coral• 20% of the world’s coral reefs have been

effectively destroyed and show no immediate prospects of recovery;

• A recent report predicts that 24% of the world’s reefs are under imminent risk of collapse through human pressures

• A further 26% are under a longer term threat of collapse

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CEBU (Philippines) - part of the Coral TriangleThreats arising from human action - 70% of the world’s coral reefs could be destroyed by 2050 unless urgent action is taken.

• Diesel leaks from fishing boats and oil spillages that contaminate the water

• Trampling by tourists - unintentional but still destroys large areas of coral

• Cyanide & dynamite fishing that destroy the reef

• Overfishing that reduce biodiversity

• Sun lotions that contaminate the corals

• Fertilizer leakage from farmland that contaminates the corals

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• Clearing reefs for port installations

• Sale of corals for the aquarium trade

• Use of the limestone (the superstructure of the reef) for building etc

• Global warming due to excessive discharge of greenhouse gasses (carbon dioxide, nitrous oxides, etc) that causes ‘bleaching’ as the polyps die

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Sustainable management of coral reefs

• Policing protected areas - to allow threatened reef populations to remain unharvested

• Education - to ensure people visiting coral reefs understand their importance as a habitat and feeding ground for a vast variety of fish and plant life

• New sustainable management rules for fishing - with quotas where necessary

• Coral farming - as a means of developing new reefs for the survival of the ecosystem

• Controls on global warming to prevent ‘bleaching’ - but this will require wide scale international cooperation

THESE ACTIONS DECIDED WITHIN A PARTNERSHIP OF THE DIFFERENT COUNTRIES MAKING UP THE CORAL TRIANGLE

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Demonstrating sustainability

• Sustainable development ensures the next generation is not disadvantaged by actions taken today.

• It is possible to have economic, social and environmental sustainable development

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Sustainable management in Cebu

• Introducing quotas (a set number of fish that can be extracted from the sea) helps prevent overfishing. It ensures that there is always sufficient fish stock to reproduce which protects the economic interests of the next generation of fishermen.

• Preventing cyanide and dynamite ‘fishing’ helps reduce overfishing and helps retain the quality of the reef, which in turn secures the biodiversity of the ecosystem, so creating a degree of environmental sustainability.

• Ensuring local people are involved in the management of the reef (such as in ‘coral farming’) creates a sense of ‘ownership’ and ‘belonging’ which leads to social sustainability.

• Additionally, this reproduction of coral ensures the long term survival of it, which will mean tourists will keep coming back, which in turn helps to sustain the economy of the area, keeping local people in business

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Sustainable management cont.

• An education programme (perhaps short video presentation on flights for example) will ensure people are made aware of the issues. This may stop them trampling across the corals and ensure they do not damage the reef. This is a lasting benefit which is therefore sustainable.

• With international cooperation and pressure put on the air and car industry global warming can be controlled. This will prevent coral ‘bleaching’ and therefore ensure the environmental sustainability of the ecosystem.

• This action will also retain stocks of fossil fuels for the next generation and by so doing ensure a degree of economic sustainability.

• If poor people are supported they will not need to turn to extreme methods of fishing (eg dynamite). This is socially and economically sustainable for local people as well as ensuring the protection of the reef in order to promote environmental sustainability

• Protecting the reef ensures the longevity of it. This will mean scientists have the opportunity to look for remedies to diseases. Tackling life threatening diseases is both economically and socially sustainable. By keeping people fit and well they are able to earn a living as well as enjoy a better quality of life.

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HOMEWORK

Research the recent oil spill disaster in the Gulf of Mexico

What caused the spill?

What is likely to be the long term impact of this disaster?

What is the response?

What are the difficulties dealing with the problem?

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Tonight’s homework

• Deadline – tomorrow!

• “With reference to a small scale example you have studied describe the threats facing it and explain why it is being managed and how this is being done sustainably”

• Intro = set the scene eg describe briefly the location of the case study and what the overall issue is

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Deconstruct the question

• With reference to a small scale example you have studied describe the threats facing it and explain why it is being managed and how this is being done sustainably