Managing marine environments

Overview

Global Commons, tragedy of the commons in a marine context and three causes of the over-exploitation of marine ecosystems.

What you need to know

Answer each one before you reveal it.

Questions from this subtopic

Each one with the model answer underneath.

1. 1

   Define the Global Commons.

   Model answer

   The Global Commons are those parts of the Earth that lie beyond national jurisdiction and are held to belong to all humanity, including the high seas, the atmosphere, Antarctica and outer space.

2. 2

   Why are the high seas treated as part of the Global Commons?

   Model answer

   They lie beyond any state's territory, so no government can claim them and their use and protection depend on collective agreement.

3. 3

   Explain the tragedy of the commons in a marine context.

   Model answer

   Each fishing fleet gains the full value of what it catches while the cost of depletion is shared by all, so it is rational for each to keep fishing until the stock collapses.

4. 4

   Define overfishing.

   Model answer

   Overfishing is catching fish faster than the population can reproduce, so the stock declines over time.

5. 5

   Name three causes of the over-exploitation of marine ecosystems.

   Model answer

   Fleet capacity and technology that far exceed what stocks can sustain, subsidies that keep unprofitable fishing going, and weak enforcement in international waters.

6. 6

   What is bycatch, and why does it matter?

   Model answer

   Bycatch is the unintended capture of non-target species, and it matters because it kills large numbers of juveniles, seabirds, turtles and marine mammals.

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