IB Geography OCEANS - Lesson 21 (Paper 1)
Give a detailed example of a country's successful use of conservation policies.
- Iceland banned all fishing by foreign fleets within their EEZ. However, fishing trawlers from Britain ignored the ban and kept fishing in Iceland's EEZ. Iceland used it's navy to prevent foreign fishing boats in coming within its EEZ. Britain sent its own navy to protect British fishing trawlers. This nearly led to a war. Eventually, Britain stayed out of Iceland's EEZ. It also implemented fishing quotas. A quota is a limit that fishing people are allowed to catch. This quota is annually adjusted based on the recommendations of marine scientists who look at the number of fish still left at the end of the year. Iceland created conservation areas, which blocked access to fishing in particular areas in order to protect spawning fish. They also banned the use of bottom dragnets. They also created strict regulations by changing the mesh size of nets. Larger mesh sizes allow young immature fish to escape. This is done to let the immature fish become mature and breed. Smaller mesh sizes are not allowed. These conservation efforts have resulted in a recovery of cod numbers and in a sustainable fish yield. Iceland now has the move successful fish conservation policies in the world today.
How can we reduce overfishing?
- can be prevented through the use of aquaculture - conservation areas -the banning of fishing fleets -the use of quotas
List three consequences of overfishing
- less and smaller fish - change in ecosystems - fishing fleets have to fish in more remote areas
negative aspect of aquaculture
- mangroves are often cleared to make space for the farming of aquaculture species. 50% of mangrove forests along the coast of Philippines have been cleared for shrimp farms - With the removal of mangrove forests, the coast is more prone to erosion from the sea - removal of mangrove forests causes loss of corals due to sedimentation - prevents mud from the land from smothering corals -mangroves can filter out sewage before it reaches the ocean - there is pollution from the heavy concentration of fish in a small area. - fish wastes cause eutrophication of the surrounding coastal area - farmed fish might escape and threaten wild fish. Example: farmed Atlantic salmon have escaped along canada's Pacific coast and interbred with the local population of the Pacific salmon. Drugs are used to keep the farmed fish healthy but can pollute the surrounding area - farmed fish can attract large numbers of sea lice to an area. These parasites then affect the wild fish in the area - farmed carnivorous fish like salmon are being fed high protein pellets made from other smaller fish. This is seen as bad since it is taking smaller fish to feed the farmed fish which in turn reduce the fish that wild populations rely on in healthy food chains.
positive aspect of aquaculture
- reduce pressure on the already overfished natural population in the wild -does not only involve fish, other aquaculture species are shrimp, shellfish (mussels) and plants like seaweed.
Reasons for overfishing
Driftnets/ Bottom Dragnets/ Modern Technology/ Pollution / too many fisherman and bycatch (wasteful method)
