an international agreement to prevent pollution from ships. It sets rules that ships of all countries must follow.

stops the oil spreading. It is a floating barrier.

Why do oiled sea birds die of cold?

their feathers no longer keep them warm. Oil sticks the feathers together so they do not trap air.

How does oil harm seaweeds and corals?

it blocks the light needed for photosynthesis. No light, no photosynthesis.

Which is a limitation of detergent sprays?

the detergents can be toxic to marine life. The cure can also do harm.

Which strategy prevents a spill, and does not clean one up?

regular maintenance of pipelines. Worn parts are replaced before they leak.

Oil pollution · Cambridge IGCSE Environmental Management

In plain words

Oil floats, spreads and sticks. A single tanker accident can coat hundreds of kilometres of coast. Yet the famous disasters are only part of the story. A great deal of oil reaches the sea a little at a time, from leaking pipelines, from drilling and from ships washing out their tanks.

10 things to know

Causes of oil pollution: off-shore and on-shore oil extraction, leaking pipelines, shipping accidents, the cleaning of tanks at sea, and spills from refineries.
Birds: oil sticks their feathers together, so they cannot fly or keep warm, and they swallow oil when they clean themselves.
Marine mammals: oil coats their fur, so they lose heat, and they breathe in or swallow it at the surface.
Fish: oil damages their gills and poisons their eggs and young. Crustaceans, which live on the sea bed and the shore, are smothered.
Seaweeds and coral reefs: a layer of oil blocks the light, so seaweeds and the algae inside corals cannot photosynthesise. Corals die.
Beaches: oil washes ashore, kills shore life, and drives away tourists, so local people lose income.
Prevention. MARPOL, the International Convention for the Prevention of Pollution from Ships, sets rules for ships, including limits on releasing oil at sea.
Double-hulled oil tankers have two layers of hull, so if the outer one is holed the oil stays in. Risk assessments identify what could go wrong before work starts. Regular maintenance finds worn parts before they fail.
Minimising the impact. Improved navigation systems help ships avoid collisions and rocks. Booms are floating barriers that stop the oil spreading. Sorbents soak oil up. Skimmers lift oil off the surface.
Detergent sprays break the oil into small droplets that spread out and are broken down by bacteria. The detergents can be toxic themselves. Controlled burning removes oil quickly but pollutes the air.

Worked example

A tanker runs aground and oil begins to drift towards a beach. Describe what can be done, in order.

Put booms around the slick to stop it spreading and to keep it off the beach.
Use skimmers inside the booms to lift the oil from the surface, and sorbents to soak up what remains.
Detergent sprays or controlled burning can deal with oil further out, although both cause pollution of their own.

Tips and tricks

Sort the strategies into the two groups the syllabus uses. Prevention: MARPOL, double hulls, risk assessments, maintenance. Minimising impact: navigation systems, booms, sorbents, detergents, skimmers, burning.
Booms contain oil. Skimmers remove it. They are used together.

6 questions, about 2 minutes.

It lands in your notebook with its questions as flashcards.

Oil pollution: 6 questions and answers

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

What is MARPOL?
- a machine that skims oil
- a type of oil tanker
- an international agreement to prevent pollution from ships (the answer)
- a chemical that breaks up oil
It sets rules that ships of all countries must follow.
What does a boom do?
- burns the oil
- stops the oil spreading (the answer)
- dissolves the oil
- sinks the oil
It is a floating barrier.
Why do oiled sea birds die of cold?
- the sea becomes colder
- oil freezes on them
- they stop eating
- their feathers no longer keep them warm (the answer)
Oil sticks the feathers together so they do not trap air.
How does oil harm seaweeds and corals?
- it blocks the light needed for photosynthesis (the answer)
- it makes the water too salty
- it adds too many nutrients
- it raises the sea level
No light, no photosynthesis.
Which is a limitation of detergent sprays?
- they make the oil spread faster on the surface
- they work only on beaches
- the detergents can be toxic to marine life (the answer)
- they cause air pollution
The cure can also do harm.
Which strategy prevents a spill, and does not clean one up?Stretch
- skimmers
- sorbents
- controlled burning
- regular maintenance of pipelines (the answer)
Worn parts are replaced before they leak.

6 questions

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

Worksheet

3 questions, 8 marks. Write your answers on paper, then check them.

Oil pollution

Cambridge IGCSE Environmental Management 0680 · 8 marks · papermunch.org

Name ______________________________ Date ______________

Explain how an oil spill harms sea birds.[3]
Show answerHide answer
Oil coats the feathers and sticks them together. The bird cannot fly or keep warm, so it may die of cold or starve. It also swallows oil when cleaning its feathers, which poisons it.
I got this one
Explain how a double hull reduces the risk of an oil spill.[2]
Show answerHide answer
The tanker has two layers of hull. If the outer layer is damaged, the inner layer still holds the oil.
I got this one
Describe three methods used to clean up oil after a spill.[3]
Show answerHide answer
Any three: booms contain the oil; skimmers remove it from the surface; sorbents soak it up; detergent sprays break it into small droplets; controlled burning burns it off.
I got this one

Answers: Oil pollution

1. Oil coats the feathers and sticks them together. The bird cannot fly or keep warm, so it may die of cold or starve. It also swallows oil when cleaning its feathers, which poisons it.
2. The tanker has two layers of hull. If the outer layer is damaged, the inner layer still holds the oil.
3. Any three: booms contain the oil; skimmers remove it from the surface; sorbents soak it up; detergent sprays break it into small droplets; controlled burning burns it off.