Syllabus concepts to know

• 4.3.1 Phytoplankton and macrophytes provide energy for freshwater and marine food webs.
• 4.3.2 Humans consume organisms from freshwater and marine environments.
• 4.3.3 Demand for foods from freshwater and marine environments is increasing due to the growth in human population and changes in dietary preferences.
• 4.3.4 The increasing global demand for seafood has encouraged use of unsustainable harvesting practices and overexploitation.
• 4.3.5 Overexploitation has led to the collapse of fisheries.
• 4.3.6 The maximum sustainable yield (MSY) is the highest possible annual catch that can be sustained over time, so it should be used to set caps on fishing quotas.
• 4.3.7 Climate change and ocean acidification are having impacts on ecosystems and may cause collapse of some populations in freshwater or marine ecosystems.
• 4.3.8 Unsustainable exploitation of freshwater and marine ecosystems can be mitigated through policy legislation addressing the fishing industry and changes in consumer behaviour.
• 4.3.9 Marine protected areas (MPAs) can be used to support aquatic food chains and maintain sustainable yields.
• 4.3.10 Aquaculture is the farming of aquatic organisms, including fish, molluscs, crustaceans and aquatic plants.
• 4.3.11 Productivity, thermal stratification, nutrient mixing and nutrient loading are interconnected in water systems.
• 4.3.12 Accurate assessment of fish stocks and monitoring of harvest rates are required for their conservation and sustainable use.
• 4.3.13 There are risks in harvesting fish at the maximum sustainable yield (MSY) rate and these risks need to be managed carefully.
• 4.3.14 Species that have been overexploited may recover with cooperation between governments, the fishing industry, consumers and other interest groups, including NGOs, wholesale fishery markets and local supermarkets.
• 4.3.15 According to the UN Convention on the Law of the Sea (UNCLOS), coastal states have an exclusive economic zone stretching 370 km out to sea, within which the state’s government can regulate fishing.
• 4.3.16 Harvesting of seals, whales and dolphins raises ethical issues relating to the rights of animals and of indigenous groups of humans.