Oceans as a Resource
How much of Earth’s surface is covered by oceans?
Over 70%
Where are most commercial fishing grounds found?
Continental shelves
What is overfishing?
Catching fish faster than they can reproduce.
What does ENSO stand for?
El Niño Southern Oscillation
What is the purpose of increasing the mesh size of nets?
Allows small/young fish to escape and breed.
Name two key resources humans extract from oceans.
Fish, salt, sand, oil, energy, etc
Why are continental shelves rich in fish?
Nutrients, light, plankton, oxygen
Why are industrial trawlers especially damaging?
Destroy seabeds, cause high bycatch, deplete stocks quickly
What happens to Pacific trade winds during El Niño years?
They weaken or reverse
What is a Marine Protected Area (MPA)?
Zone where fishing is restricted/banned to allow ecosystems to recover.
What is desalination, and why is it important?
Turning seawater into drinking water; helps with freshwater shortages
Define bycatch and explain why it’s a problem.
Unwanted animals (dolphins, turtles) killed in nets
How has climate change intensified pressure on oceans?
Species migration, acidification, coral bleaching, habitat shifts
Explain why Peru experiences heavy rainfall during El Niño.
Warm water shifts east; air rises, causing convection and rain
How do quotas help conserve fisheries?
Limit catches, prevent overfishing, allow stock recovery
Explain why oceans are vital for global energy balance
They absorb 67% of solar energy and redistribute heat
Assess the impacts of fish farming (aquaculture).
Provides food but creates pollution, disease, reliance on feed fish
Explain why fish are described as the “last wild food resource.”
Unlike livestock, most fish are still hunted in the wild rather than farmed.
Describe two impacts of El Niño on fisheries along South America.
Nutrient upwelling reduced results in fish stocks collapse; jobs lost; marine biodiversity declines.
Give one example of an international ocean management law.
UNCLOS, CITES, International Whaling Commission
Evaluate the sustainability of using oceans for minerals and energy
Benefits: food, minerals, energy. Risks: over-extraction, pollution, ecosystem collapse
“Overfishing is a tragedy of the commons.” Discuss
Overfishing fits the tragedy of the commons model because open access + competition leads to overuse.
However, it is not inevitable: good governance, community rights, and international cooperation can prevent collapse.
Strongest evaluation: It depends on management — unmanaged fisheries are a tragedy, but regulated ones can be sustainable.
Evaluate the risks of global fish stock collapse for food security.
Protein source for 3 billion people threatened; livelihoods lost; malnutrition risk, especially in developing countries.
''El Niño is a local event with global consequences.” Discuss.
Local origin in Pacific; global effects include drought in Australia, floods in Peru, disrupted jet streams, agricultural losses worldwide.
Evaluate whether Marine Protected Areas are the best solution to overfishing.
They restore biodiversity and fish stocks; but enforcement is weak, migratory species remain vulnerable, and restrictions may hurt short-term livelihoods.