EFFECTS OF OIL POLLUTION

The effects of oil spills are difficult to predict because they depend on a number of factors, including the type of oil spilled (crude or refined), amount, distance of the spill from shore, time of a year, weather conditions, and ocean and tidal currents. Crude oil, refined oil are collections of hundreds of substances with widely different properties. After an oil spill, low-boiling aromatic hydrocarbons are the primary causes of the immediate killing of a number of aquatic organisms, especially in their larval forms. Fotunately, most of these toxic chemicals evaporate into the atmosphere within a day or two. Some other chemicals remain on the surface and form small, floating, tarlike globs. These floating subxtances are gradually broken down by bacteria over several weeks or months, although they persist much longer in cold polar waters.

Floating oil can coat the feathers of marine birds, especially diving birds, and the fur of marine mammal such as seals and sea otters. This oily coating destroys the animals natural insulation and buoyancy, and most of them drown or die of exposure from loss of body heat. It is estimated that nearly 150,000 – 450,000 marine birds in the North Sea and the North Atlantic regions are killed each year by chronic oil pollution, mostly from routine tanker releases.

Heavy oil components that sink to the ocean floor or wash into estuaries are believed to have the greatest long-term impact on marine ecosystems. These components can kill bottom-dwelling organisms such as crabs, oysters, mussels and clams or make them unfit for human consumption because of their oily taste and smell.

Oil slicks that wash onto beaches can have serious economic effects on coastal residents, who lose income from fishing and tourist activities. Oil-polluted beaches washed by strong waves or currents are cleaned up fairly, but beaches in sheltered areas remain contaminated for several years. Oil clean-up is very expensive for oil companies and coastal communities.

Studies of the effects of several crude oil spills in the open sea between 1989 and 1998 found that most forms of marine life recovered nearly completely within 3 years. In contrast, spills of oil, especially refined oil, near shore or in estuarine zones, where sea life is most abundant, have much more damaging and long-lasting effects. For example, damage to estuarine species from 1989 spill of refined oil at West Falmouth, Massachusetts, was still being detected 10 years later.

18. Answer the following questions.

1. Why is it so difficult to predict the effects of oil spills?

2. What is the primary cause of the immediate killing of aquatic organisms?

3. What do toxic chemicals do?

4. What are floating substances gradually broken down by?

5. What can floating oil coat?

6. What can heavy oil components do when they sink to the ocean floor?

7. Why do oil slicks have serious economic effects on coastal residents?

8. What examples of the effects of oil spills can you give?

19. Find Ukrainian equivalents for the following English terms.

20.Word-play. Find the hidden words in this square. Some appear vertically, some horizontally, and some diagonally. Use the clues below to help you. The number of letters in each word and the first letter of the word appear in brackets after the clue.

Find the words which mean:

1. An animal that has smooth fur, eats fish and lives by the sea in cold areas. (4,S)

2. (pl) Very small living things, some of which cause disease. (8,B)

3. A small sea animal with a black shell and soft body that you can eat. (6,M)

4. A small sea animal that has a shell and produces a jewel called a pearl. (6,O)

5. The wide part of a river where it joins the sea. (7,E)

6. All the animal and plants in an area, and their relation to each other and their environmental. (9,E)

7. Ability to float. (8,B)

8. Relating to the sea or living in the sea. (6,M)

21. Decide whether the following statements are true (T) or false (F) in relation to the information in the text. If you think a statement is false, change it to make it true.

1. ___ It is difficult to predict the effects of oil spills because many factors influence on them.

2. ___ Crude oil and refined oil have the same substances.

3. ___ High-boiling aromatic hydrocarbons immediately kill many aquatic organisms in their larva forms.

4. ___ Most of toxic chemicals evaporate into the atmosphere, others remain on the surface.

5. ___ Floating oil coats the feathers or fur of marine organisms and destroys animals’ buoyancy and natural insulation.

6. ___ Heavy oil components that sink to the ocean floor have short-term impact on marine ecosystems.

7. ___ Heavy oil components kill crabs, oysters, mussels or make them unfit for human consumption.

8. ___ Sheltered areas can be cleaned up more rapidly than oil-polluted beaches.

22. Circle the correct answer.

1. The effect of oil spills can ... with great difficulties.

a) predict c) be predicted

b) to predict d) predicted

2. Such factors as type of oil spilled, amount, dictance of the spill from shore, weather conditions ... on the effects of oil spills.

a) influencing c) influenced

b) influence d) influences

3. These floting substances ... by bacteria over several weeks or months.

a) is broken down c) are broken down

b) break down d) broke down

3. Heavy oil components ... to have the greatest long-term impact on marine ecosystem.

a) are believed c) believe

b) can believe d) is believed

4. Oil slicks can ... serious economic effects on coastal residents.

a) to have c) have

b) has d) be having

5. Oil-polluted beaches ... by strong waves are cleaned up rapidly.

a) is washed c) are washed

b) washed d) wash

23.Put special questions to the underlined words.

1. The effects of oil spills depend on a number of factors, namely type of oil spilled, amount, weather conditions, etc.

2. Crude oil and refined oil inlude hundreds of substances with different properties.

3. The floating substances are gradually broken down by bacteria.

4. Oily coating destroys the animals’ natural insulation and buoyancy.

5. 150,000 – 450,000 marine birds in the North Sea and the North Atlantic regions are killed each year by chronic oil pollution. (2 questions)

24.Give definitions for the following terms.

Crude oil, aquatic organism, sheltered area, ecosystem, oil spill.

25. Read the following text and translate it in a written form.