Back to ESS Topics
4.3.11 min read

Aquatic systems as natural capital

IB Environmental Systems and Societies • Unit 4

AI-powered feedback

Stop guessing — know where you lost marks

Get instant, examiner-style feedback on every answer. See exactly how to improve and what the markscheme expects.

Try It Free

Aquatic systems as natural capital

Big idea: Oceans, lakes, and rivers are natural capital — they provide food, regulate climate, and support billions of livelihoods. Fish stocks are renewable natural capital that can regenerate IF we harvest them sustainably.

Ecosystem services from aquatic systems

  • Provisioning — fish, shellfish, seaweed, freshwater
  • Regulating — climate regulation, carbon storage, water purification
  • Supporting — nutrient cycling, habitat for biodiversity
  • Cultural — recreation, tourism, spiritual value

Renewable but not unlimited

Fish populations CAN regenerate, but only if we harvest at or below the maximum sustainable yield (MSY). Overfishing pushes stocks below this point, causing collapse.

Renewable does not equal infinite! Fish are renewable natural capital, but overfishing can make them effectively non-renewable if populations collapse below recovery threshold.

Don’t just read about Aquatic systems as natural capital — practice it

Apply what you learned with real exam-style questions. AI feedback shows exactly how to improve your answers.