l05 value of oceans

IB Geography: Oceans and their Coastal Margins

IB Oceans and their Coastal Margins

B3 – The Value of Oceans


• World’s oceans represent a valuable resource base for the planet.– Biotic – relating to living organisms– Abiotic – non-living chemical and physical factors.

Resource Base


Resources• The world’s oceans provide many products

that are useful for humans.• Accessing resources is more difficult in the

deep oceans than in the shallow continental shelves.

• The margins of the oceans have the greatest demands on them.

• As technology develops and cost structures change even the deepest and remote ocean areas are seen as being able to provide resources for human use.


Fishing• Most useful biotic resource that the ocean

provides for humans is fish.• Fish supplies 16% of the world’s protein to

humans.• Fishing is conducted at a wide range of scales

from individual people casting nets to large trawlers that operate like factories.

• Most fish are used for human consumption.• Other use of fish are feeding animals or provide

oils as raw materials for industrial processes.


Transport• Although people tend to travel long distances

by Air humans still use oceans for transport.• Long-distance shipping is widely used to

transport cargo in various types of ships including bulk oil tankers and container ships.

• Oceans are also used for communications as long-distance telephone, internet and data cables are laid across the ocean floor.


Tourism• An increasingly important use for oceans as a

resource.• Most tourism related to oceans occurs on the

margins, such as beaches and the shallow waters of the continental shelves.

• Some cruise liners carry passengers across the oceans between continents.


Abiotic Resources: Minerals• Ocean resources are increasingly being used as a

source for minerals.• It is more difficult and more expensive to mine

the oceans than the land.• If the resource is significantly valuable it justifies

the high cost.• Unfortunately mining in the oceans often causes

destruction of natural ecosystems.• When dredging occurs the ocean floor is totally

destroyed wiping out all marine habitats and breeding grounds.


Fishing• Traditional fishing methods were defined to

obtain food for subsistence purposes.• Today fishing within most LEDCs takes only the

quantities of fish needed for food in the local community.

• Under traditional fishing fish remains a renewable resource.


Commercial Fishing• Commercial fishing provides an incentive to catch as many

fish as possible to make as much money as possible.• The fishing industry has a great difficulty conserving

resources in part because fish can move across boundaries.• Within any country their can be enforcement of rules

about size of fish and bag limit.• Actions can help to conserve fish stock in estuaries and

coastal waters when there are sufficient inspectors to police regulations.

• Destruction of breeding habit may be counteracting conservation measures.


Fishing Stocks• Fish may move great distances during their life cycle

and this will mean crossing the boundaries of countries’ control.

• Territorial waters now extend some 320 kilometers from the shore and that means there is an overlap between many countries; or dispute where the line should be placed.

• Many countries enter other countries territorial waters and remove food and other sources of food.

• Patrolling can go some way to seeing that conservation measures are observed.


Dwindling Fish Stocks• When fishermen are taking undersized fish stocks near an

ocean border they are depleting breeding stock on both sides.

• Much more efficient techniques have been developed in recent years:– Air and radar surveillance to locate fish schools.– Larger, faster, better equipped factory ships to process

and preserve the catch.– Better netting techniques that often require the team

work of a number of fishing boats.


Increasing Fishing• As well as fishing becoming more intensive the size

of the world fishing fleets grew enormously.• Fish can now be caught in quantities that threaten

the survival of species.• Drift net is still being used by fishers from some

countries despite being banned in international agreements.

• The drift net is almost invisible and snares virtually everything that is unluckily enough to swim into it.

• The drift net cannot exclude protected species.


Special Fish• There are special markets for particular fish, such

as tuna in Japan or the coral trout in Hong Kong.• The price that fishers can obtain encourages them

to take greater risks of breaching territorial waters.

• Coral trout has been taken from the protected marine park of the Great Barrier Reef to appear later in Hong Kong restaurants as the result of illegal fishing.

• The price that people are willing to pay influences whether conservation will be successful.


Conservation of Fisheries• Conservation measures are only having a minor

impact.• Trend in marine fish catches has been downwards

since about 1970 – though there is a greater success in catching what fish are actually there.

• Traditional fish sought by the industry are over exploited.

• Size of the catch is being maintained by some non-traditional species such as sprat or Pollock.

• This will allow the size of the yield to be maintained though not through active conservation.


Whaling• Breaches of restrictions on whaling receive more

publicity than the steep reductions in the stocks of fish.

• Conservation of Whaling has been successful in terms of conservation.

• Japan and Norway still do not recognise some international agreements.

• Numbers of whale species have shown a steady increase in their last two decreases.

• Many places they contribute to ecotourism as people are fascinated by them.


QuestionDescribe the issues involved in the management of

fish as a resource?

l05 value of oceans

Technology

size of fish

use of fish

quantities of fish

traditional fishing

particular fish

fish schools

fish supplies

marine fish catches