Where are coral reefs found?

in warm, shallow, clear water. The algae in coral need sunlight.

What causes coral bleaching?

sea temperatures that are too high. The coral loses its algae and turns white.

Which is a major cause of mangrove loss?

clearance for shrimp farming. Coastal development and cutting for wood also destroy them.

How do coral reefs protect coasts?

They break the force of waves before they reach the shore. A reef acts as a natural breakwater.

What is a marine protected area?

an area of sea where damaging activities are restricted. Fishing, anchoring or tourism may be limited or banned.

Coral reefs and mangroves · Cambridge IGCSE Geography (9

In plain words

Two living coastlines protect tropical shores better than any sea wall: reefs built by tiny animals, and forests that grow with their roots in salt water. Both are disappearing fast.

7 things to know

Coral reefs are found in warm, shallow, clear, salty water, mostly between 30° north and south of the Equator. Corals need water of about 23 to 29 °C, and sunlight for the algae that live in them.
Mangroves are trees that grow in salt water along sheltered tropical and subtropical coasts and river mouths.
Importance of coral reefs: they hold a huge variety of species, they protect coasts by breaking waves, they support fishing, and they bring tourists.
Importance of mangroves: they absorb wave energy and storm surges, trap sediment, shelter young fish, and store carbon.
Threats to coral reefs: warmer seas, which cause coral bleaching; more acidic seas; pollution and sediment from the land; overfishing and destructive fishing; and damage by tourists and boat anchors.
Threats to mangroves: clearance for shrimp farms, for building and for tourism; cutting for wood; and pollution.
Management: marine protected areas, limits on fishing, controls on tourism, treating sewage, replanting mangroves, and education. Protection that involves local people is more likely to last.

Worked example

Explain what coral bleaching is and why it is happening more often.

Corals contain tiny algae, which give them their colour and most of their food.
When the sea becomes too warm, the stressed coral pushes the algae out and turns white.
If the water stays warm, the coral starves and dies.
Climate change is warming the oceans, so bleaching is becoming more frequent.

Tips and tricks

Give conditions for coral as a list of four: warm, shallow, clear and salty water.
For "importance", think of four kinds: wildlife (biodiversity), protection of the coast, food and income.

5 questions, about 2 minutes.

It lands in your notebook with its questions as flashcards.

Coral reefs and mangroves: 5 questions and answers

These are the quiz’s questions. Do the quiz first, then come back here for the ones that got you.

Where are coral reefs found?
- in cold, deep water
- in warm, shallow, clear water (the answer)
- in fresh water lakes
- at river mouths full of sediment
The algae in coral need sunlight.
What causes coral bleaching?
- cold water
- sea temperatures that are too high (the answer)
- too many fish
- strong tides
The coral loses its algae and turns white.
Which is a major cause of mangrove loss?
- coral bleaching
- clearance for shrimp farming (the answer)
- cold winters
- sand dunes
Coastal development and cutting for wood also destroy them.
How do coral reefs protect coasts?
- They raise the land.
- They break the force of waves before they reach the shore. (the answer)
- They absorb rainfall.
- They block rivers.
A reef acts as a natural breakwater.
What is a marine protected area?
- a harbour
- an area of sea where damaging activities are restricted (the answer)
- a fish farm
- a beach resort
Fishing, anchoring or tourism may be limited or banned.

5 questions

Tap an answer and you’ll see straight away whether it’s right, and why.

Worksheet

3 questions, 11 marks. Write your answers on paper, then check them.

Coral reefs and mangroves

Cambridge IGCSE Geography (9–1) 0976 · 11 marks · papermunch.org

Name ______________________________ Date ______________

State three conditions needed for coral reefs to grow.[3]
Show answerHide answer
Warm water, between about 23 and 29 °C. Shallow water, so that sunlight reaches the coral. Clear water, free from sediment. (Also: salt water.)
I got this one
Explain two reasons why mangroves are important.[4]
Show answerHide answer
They protect the coast, because their roots and trunks absorb the energy of waves and storm surges. They are nursery areas where young fish shelter, which supports fishing.
I got this one
Describe two strategies used to protect coral reefs.[4]
Show answerHide answer
Marine protected areas, where fishing and other damaging activities are banned or limited. Controls on tourism, such as limiting visitor numbers and banning anchors on the reef.
I got this one

Answers: Coral reefs and mangroves

1. Warm water, between about 23 and 29 °C. Shallow water, so that sunlight reaches the coral. Clear water, free from sediment. (Also: salt water.)
2. They protect the coast, because their roots and trunks absorb the energy of waves and storm surges. They are nursery areas where young fish shelter, which supports fishing.
3. Marine protected areas, where fishing and other damaging activities are banned or limited. Controls on tourism, such as limiting visitor numbers and banning anchors on the reef.