1. Coral Reefs
By: Alica Majercinova
Geography 12

2. What is Coral Corals are tiny animals, called polyps
Each coral has a stony cup of limestone around itself as a skeleton
As they grow, the polyps divide and form coral colonies
These colonies build up on top of each other and form coral reefs
These reefs are found in warm
tropical waters mostly between the
Tropics of Cancer and Capricorn

4. Why is Coral Important
Coral reefs are considered to be one of the most beautiful, natural habitats in the world
They are homes to large numbers of different species both plants and animals
More species of fish are found on reefs than anywhere else in the ocean, ranging from large sharks to tiny gobies

5. Why is Coral Important
These animals provide much of the local food and new medication
They have the second greatest diversity of species after the tropical rainforests
Important for tourism and local economy
They provide costal protection

6. Types of Reefs Fringing or Apron reefs Barrier reefs Atoll reefs
Patch reefs
Ribbon reefs
Table reefs
Bank reefs

7. Fringing (Apron) Reefs
They lie around islands and they are attached directly to the shore
It is separated from the shore by narrow shallow lagoons which usually have a sandy bottom and sometimes sea grasses
Shorter fringing reefs that are more sloped are often called apron reefs

8. Barrier Reefs
They grow on the edge of continental shelves and are not attached to the shore
It is separated from the mainland by deep and wide lagoons
These reefs are the largest in the world and include the Great Barrier Reef in Australia, which is about 2000 km long, and the Belize Barrier Reef in the Caribbean

9. Atoll Reefs
Atolls form when islands (usually the tops of underwater volcanoes) surrounded by fringing reefs sink into the sea or when sea level rises around them
The fringing reefs keep growing and eventually form circles with lagoons inside
Most atolls are found in the Pacific, some in the Indian Ocean and a few in the Caribbean

10. Patch Reefs
They are much like barrier reefs but form small patches of coral reefs instead of one large piece
Patch reefs are often circularly shaped and surrounded by a lagoon

11. Ribbon Reefs These reefs are fairly winding
Most ribbon reefs are thin and long
They are usually connected to an atoll lagoon

12. Table Reefs A small, isolated organic reef which has a flat top
They are future atolls but they are not yet connected to a lagoon.

13. Bank Reefs Look like the patch reefs but they are larger
Often have a hemispherical shape

14. Coral Reefs are Threatened
They are one of the world’s least protected natural habitats
Nearly 60% of the worlds's coral reefs are threatened by human activity
ranging from coastal development, overexploration, overfishing, and inland pollution

15. Causes Climate change and global warming Pollution Sedimentation
Toxic runoff

16. Impacts Coral bleaching is caused by increased water temperatures
Coral is completely dependent on zooxanthellae, which is a microscopic algae that lives in the coral tissue and provides it with most of its nutrients
The coral expels its microscopic algae that is responsible for its color
The coral can’t get nutrients easily without its algae and dies

18. Impacts
Sedimentation is when sediment from rivers and large amounts of erosion flow into the sea and carry the pollutants and fertilizers from the farms and factories
This sediment covers the coral reefs and affects the coral itself and all the species
Overuse of fertilizers adds nitrogen to the ocean and increases algae growth, which takes oxygen and blocks coral from sunlight

19. Impacts Runoff has a very dangerous impact on the reefs
The waste that runs into the oceans from industries and farms contains toxic chemicals that can weaken and kill coral and other organisms
An increase in chlorophyll in the water leads to a larger crown-of-thorns starfish population
This type of starfish eats the coral and can do very much damage

20. Why is This a Problem
The natural habitat is being destroyed having a large impact all over the world
Most of the species are threatened
The local economy, costal development and tourism is at risk
The medication that is only made from coral might not be available in the future-marine species are a major focus for new cancer research

21. What Can be Done? creating marine parks that, in turn, create new jobs
treating sewage before it reaches the reefs
well-managed marine protected areas system is one of the most effective ways for assuring healthy reefs, while generating tourism with good business and maintaining the nearby fisheries.

22. I Think…
Coral reefs are very important and it is up to us to decide if we want the coral reefs to survive
We all need to contribute by just a little to make a big difference

23. The End