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Unit 6 Save the Oceans
Unit 6
Save the oceans
Unit 6 Save the Oceans
What are the problems that our
oceans
face?
 Over-fishing
Improved fishing equipment has greatly increased the amount
of fish caught, fishermen can now travel further out to sea.
Radar
Crew’s quarters
Fuel tank
Factory deck
Engine room
Cold store
Unit 6 Save the Oceans
What are the problems that our
oceans
face?
 Over-fishing
The boats are fitted with sonar equipment to locate fish
shoals. Fishermen use nets with smaller mesh sizes, so young
fish was caught.
Unit 6 Save the Oceans
What are the problems that our
 Over-fishing
oceans face?
Fish with commercial value are
regularly caught in large quantities
are decreasing rapidly.
Whale
Over-fishing
has depleted
many fish
stocks such as
salmon, tuna
and whale.
Tuna
Salmon
Unit 6 Save the Oceans
What are the problems that our
oceans face?
 Over-fishing
Many species of
whale are now near
extinction. Today,
less than 1% of the
original population
of the giant blue
whale remains.
Blue whale
Of the humpback whales, only
3% remains.
Humpback whale
Unit 6 Save the Oceans
What are the problems that our
oceans face?
 Pollution
The release of harmful substances into the environment.
For a long time man has looked upon oceans as a
bottomless dumping ground for waste.
The amount of waste discharged into oceans has greatly
increased because of the rapid development of industries
and cities along the coast.
Unit 6 Save the Oceans
What are the problems that our
oceans face?
Pollutant : Industrial waste from industries along the coast.
Unit 6 Save the Oceans
What are the problems that our
oceans face?
Pollutant :
City sewage
from densely
populated
coastal
regions.
Unit 6 Save the Oceans
What are the problems that our
oceans face?
Pollutant :
Fertilizers and pesticides
used in farming carried
into the sea by rivers.
Unit 6 Save the Oceans
What are the problems that our
oceans face?
Pollutant :
Oil leakage from ships
and offshore oil mining.
Unit 6 Save the Oceans
What are the problems that our
oceans face?
Pollutant : Fallout from
nuclear tests and dumping
radioactive waste into oceans.
Radioactive waste should be handled carefully, otherwise our ocean
will be seriously polluted.
Unit 6 Save the Oceans
What are the problems that our
oceans face?
 Toxic chemicals
Pollutants found in oceans
include plastics, toxic
chemicals such as DDT and
PCBs, and heavy metals such
as lead, mercury and zinc.
These pollutants enter
the food chain and stay
inside the body of fish
and marine animals.
They affect the
reproductive
ability of fish,
marine animals
and birds.
Unit 6 Save the Oceans
What are the problems that our
oceans face?
 Oil as a pollutant
Oil is leaked out from ships in
accidents or from oil wells. The
damage done by oil spills is enormous.
The ecosystems of marine plants and
animals are ruined.
Unit 6 Save the Oceans
What are the problems that our
oceans face?
On 24th March 1989, the oil supertanker Exxon Valdez ran aground
in Prince William Sound, Alaska.
250 000 barrels of oil poured into
the sea.
Internet
Unit 6 Save the Oceans
What are the problems that our
oceans face?
A large amount of oil
was released into the
Persian Gulf during
the Gulf War in 1991.
More than 770 km of the
coast of Saudi Arabia was
coated with a thick dark
layer of oil.
Unit 6 Save the Oceans
What are the problems that our
oceans face?
 Nuclear waste
The United States and France have repeatedly carried out
nuclear tests in the South Pacific.
These tests destroy the delicate coral islands and the
fallouts pollute the seas around them.
Oceans are used as a burial ground for radioactive waste.
Unit 6 Save the Oceans
What are the problems that our
oceans face?
 Dredging of the seabed
The dredging of the seabed and
the dumping of materials
muddy the sea water.
The fish and animal population
falls as food becomes less and
their breeding grounds
destroyed.
Unit 6 Save the Oceans
How can we save our oceans?
Each day Hong Kong discharge over 1.5 million
cubic metres of untreated sewage into Victoria Harbour.
Very bad
smell
Blackish
coloured
water
Bacterial
contamination is
extremely high
Very poor
coastal water
quality
Unit 6 Save the Oceans
How can we save our oceans?
Treatment of sewage
In 1989, the Environmental Protection Department
completed the Sewage Strategy Study which developed an
overall strategy for the management of sewage.
A major part of the strategy was the Strategic Sewage
Disposal Scheme which would collect sewage in the harbour
areas through deep tunnels and transport it to a treatment
plant at Stonecutters Island.
The sewage would be treated, by adding chemicals followed
by sedimentation, then discharged in the deep ocean water
south of Lamma Island.
The Environment Hong Kong 1997
Unit 6 Save the Oceans
The Strategic Sewage Disposal Scheme
N

Kwai Chung SP
Tsing Yi Island
To Kwa Wan SP
SP
Stonecutters
treatment plant
Kwun Tong SP + PS
North Point SP
Tseung Kwan O SP
Central SP
Treatment Plant
Shau Kei Wan SP
Wanchai East SP
Sandy Bay SP
Chai Wan SP
Aberdeen SP
Ap Lei Chau SP
Lamma Island PS
Treatment Plant
SP
Screening
Plant
PS
Pumping
Station
Tunnel
km
Effluent
Discharge
The Strategic
Sewage
Disposal
Scheme
ensures that
all sewage
will be treated
before being
discharged
into deep
ocean to the
south of
Lamma
Island in
future.
Unit 6 Save the Oceans
How can we save our oceans?
Ban nuclear tests and dumping of waste
International co-operation is needed for the successful
protection of the marine environment.
Nations should
agree to stop the
dumping of toxic
waste into oceans.
Industrial waste and
sewage should be
properly treated before
being discharged into
the sea.
United Nations offices in Vienna, Austria
Unit 6 Save the Oceans
How can we save our oceans?
Ban nuclear tests and dumping of waste
Nuclear tests should be banned to stop nuclear fallout from
polluting our oceans.
+
Unit 6 Save the Oceans
How can we save our oceans?
Better management of
ocean fisheries
There is a need for all fishing
nations to agree on fish catch
quotas. Depleted species must
be allowed the time and space
to breed and grow again.
Salmon
Minimum net mesh sizes
should be set to allow smaller,
younger fish to live and grow.
Humpback whale
Unit 6 Save the Oceans
How can we save our oceans?
Sanctuaries for
endangered species
The International Whaling Commission
has established whale sanctuaries in the
Indian Ocean, the Atlantic west to
South Africa, the Southern Ocean near
Antarctica and in the South Pacific.
Internet
Whale meat
The International
Whaling Commission
Unit 6 Save the Oceans
How can we save our oceans?
Sanctuaries for endangered species
Since 1999 the Chinese
Government has banned
fishing by trawlers in the
South China Sea in June
and July each year.
The purpose of the ban
is to allow fish to
regenerate and to stop
further depletion.
Unit 6 Save the Oceans
How can we save our oceans?
Environmental awareness
Internet
As individuals we must develop
a responsible attitude towards
the marine environment.
The best way to do this is by
joining local green groups.
Internet
The Hong Kong Marine
Conservation Society
Internet
Internet
Unit 6 Save the Oceans
Terms to Learn
Fish shoals (魚群) -- large groups of fish swimming
together.
Sewage (污水) -- liquid waste materials that flow in pipes
to the sea or to a treatment plant.
Pollutants (污染物) -- substances harmful to humans or
the environment.
DDT -- a toxic chemical. Its full name is Dichlorodiphenyltrichloroethane.
PCBs -- a toxic chemical. Its full name is Polychlorinated
biphenyls.