Unit 3.3 - Oceans - Marine Management

Question 1

What are the global commons and why are they important?

Answer 1

International law identifies four global commons: the oceans, the atmosphere, Antarctica and outer space. It is the best long-term interest of individual states to collaborate on making sure that sustainable use of the global commons is achieved over time. This is because the atmosphere and oceans deliver vital services to all human societies by regulating climate and achieving transfers of heat and water from place to place, amongst other things.

Question 2

What is over-fishing? How does this afect marine ecosystems?

Answer 2

Excessive hunting of one fish species, such as cod or tuna, can trigger other impacts.
Sharks can no longer catch enough tuna and their numbers fall too. In contrast, numbers of organisms lower down the food chain might actually increase at first (mackerel numbers could boom with fewer tuna preying on them). The worst case scenario is a complete fish stock collapse. For example, the collapse of the Newfoundland Grand Banks cod fishery in Canada in 1992.

Question 3

How is over-fishing managed?

Answer 3

• The United Nations Food and Agriculture Organisation (FAO) ensures long-term conservation and sustainable use of marine resources.
• FAO establishes marine protected areas (MPAs) globally.
• The EU’s Common Fisheries Policy (CFP) conserves European fish stocks.
• Local actions include no-take zones, such as Lamlash Bay in Arran, UK.
• Business attitudes include aquaculture, where intensively-farmed salmon and cod are raised in caged enclosures.
• Citizen campaigns and choices can help combat unsustainable fishing.