What you’ll learn16 learning objectivesChoose one objective for a focused lesson, or study the complete topic.4.3.1Aquatic primary producers• Phytoplankton: microscopic photosynthetic plankton• Macrophytes: visible aquatic plantsSyllabus objective4.3.2Human aquatic food consumption• Organisms from freshwater and marine environmentsSyllabus objective4.3.3Increasing demand• Human population growth, dietary preference changesSyllabus objective4.3.4Unsustainable harvesting practices• Bottom trawling, ghost fishing, poisons, explosivesSyllabus objective4.3.5Fishery collapse• Dramatic, lasting stock decrease• Example: Newfoundland codSyllabus objective4.3.6Maximum sustainable yield (MSY)• Highest annual catch sustainable over time• Used to set fishing quotasSyllabus objective4.3.7Climate change impacts• Ocean acidification• May cause population collapse in aquatic ecosystems• Example: coral bleachingSyllabus objective4.3.8Mitigation strategies• Policy legislation for fishing industry• Consumer behaviour changes• Permits, quotas, seasons, mesh size, zones, labellingSyllabus objective4.3.9Marine Protected Areas (MPAs)• Support food chains, maintain sustainable yields• Provide shelter and spawning groundsSyllabus objective4.3.10Aquaculture• Farming of aquatic organisms• Expanding for food supply and economic development• Impacts: habitat loss, pollution, disease spread, escapeesSyllabus objective4.3.11(HL)—Water system interconnections• Productivity, thermal stratification, nutrient mixing/loading• Highest productivity near coastlines and shallow seasSyllabus objective4.3.12(HL)—Fish stock assessment• Required for conservation and sustainable use• Monitoring harvest ratesSyllabus objective4.3.13(HL)—MSY risks• Estimated value, inevitably inaccurate• Exceeding rate → positive feedback → rapid declineSyllabus objective4.3.14(HL)—Overexploited species recovery• Requires cooperation: governments, industry, consumers, NGOs• Measures: fishing bans, license limits, bycatch preventionSyllabus objective4.3.15(HL)—UNCLOS• Exclusive economic zone: 370 km from coast• High seas (60% of ocean): limited regulation• Equity issues when countries sell fishing accessSyllabus objective4.3.16(HL)—Marine mammal harvesting ethics• Seals, whales, dolphins• Animal rights vs. indigenous group rightsSyllabus objective