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Aquatic Biodiversity

Aquatic Biodiversity. Chapter 8. Core Case Study: Why Should We Care about Coral Reefs? (1). Biodiversity Formation Important ecological and economic services Moderate atmospheric temperatures Act as natural barriers protecting coasts from erosion Provide habitats

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Aquatic Biodiversity

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  1. Aquatic Biodiversity Chapter 8

  2. Core Case Study: Why Should We Care about Coral Reefs? (1) • Biodiversity • Formation • Important ecological and economic services • Moderate atmospheric temperatures • Act as natural barriers protecting coasts from erosion • Provide habitats • Support fishing and tourism business • Provide jobs and building materials • Studied and enjoyed

  3. Core Case Study: Why Should We Care about Coral Reefs? (2) • Degradation and decline • Coastal development • Pollution • Overfishing • Warmer ocean temperatures leading to coral bleaching • Increasing ocean acidity

  4. Key Concepts What is the general nature of aquatic systems? Why are marine aquatic systems important? How have human activities affected marine ecosystems? Why are freshwater ecosystems important? How have human activities affected freshwater ecosystems?

  5. 8-1 What Is the General Nature of Aquatic Systems? 1) Most of the earth is covered with water a) Saltwater covers 71% b) Freshwater covers 2.2% 2) The global ocean is a single body of water, but divided into 4 large oceans 3) Aquatic life zone: water “biomes” a) saltwater or marine b) Freshwater

  6. 4) Aquatic species a) Plankton: weakly swimming or free-floating 1. Phytoplankton: plant like 2. Zooplankton: animal like 3. Ultraplankton: small photosynthetic bacteria b) Nekton: Strong swimming consumers c) Benthos: bottom dwellers d) Decomposers: mostly bacteria, break down material

  7. 5) Key factors determining type & number a) Temperature b) Dissolved oxygen c) Food d) Light & nutrients for PSN 6) Euphotic zone: area where PSN can occur, reduced by turbidity (cloudiness)

  8. 8-2 Why Are Marine Aquatic Systems Important? 1) Important ecological and economic resources Page 165

  9. Fig. 8-6, p. 173

  10. 2) Reservoirs of diversity a) Coastal Zone: 1. Warm, nutrient rich shallow water from high tide to continental shelf edge 2. Less than 10% of ocean, but 90% of marine species b) Estuaries: Where rivers & ocean meet c) Coastal Wetland: coastal area covered by water all or part of the year d) Very productive because of nutrients from rivers & land, circulation of nutrients & sunlight

  11. Fig. 8-7, p. 173

  12. Fig. 8-8, p. 174

  13. e) Seagrass beds: 1. Consists of at least 60 species of plants growing underwater in shallow marine areas or estuaries. 2. Support a wide variety of marine species and help stabilize shorelines, & reduce wave impacts f) Mangrove forests: 1. Tropical salt marsh (especially SE Asia) 2. Include 69 different tree species 3. Many important services (page 168)

  14. Fig. 8-10, p. 175

  15. 3) Rocky and Sandy Shores a) Intertidal Zone: 1. area between High and low tide 2. Must be able to survive extremes & avoid being wasted out to sea b) Rocky shores have pools & other microhabitats c) Barrier beach (sandy shore): Most survive by burrowing, digging or tunneling in the sand, also home for many other organisms d) Barrier islands form parallel to shore and protect from strong waves

  16. Fig. 8-11, p. 176

  17. 4) Coral Reefs Are Amazing Centers of Biodiversity a) Provide homes for ¼ of all marine species b) Aquatic equivalent of the rain forest 5) Open Sea & Ocean floor a) Open Sea: Begins at the edge of the shelf b) 3 Zones 1. ) Euphotic: where light penetrates for PSN 2. Bathyal: dimly lit middle zone 3. Abyssal: Dark, very cold area 6) Most animals in the abyssal zone feed on marine snow & are deposit or filter feeders (page 170)

  18. Fig. 8-12, p. 177

  19. 8-3 How Have Human Activities Affected Marine Ecosystems?

  20. Case Study: The Chesapeake Bay—an Estuary in Trouble page 172 • Largest estuary in the US; polluted since 1960 • Population increased • Point and nonpoint sources raised pollution Phosphate and nitrate levels too high • Overfishing 1983: Chesapeake Bay Program Update on recovery of the Bay Should we introduce an Asian oyster?

  21. 8-4 Why Are Freshwater Ecosystems Important? 1) Lentic: Standing water: lakes, ponds wetlands 2) Lotic: flowing, rivers and streams 3) Services Page 174

  22. 4) Lakes: natural bodies of standing water 5) Zones: a) Littoral: near the shore, shallow sunlit water, rooted plants can grow here, very diverse b) Limnetic: open sunlit surface c) Profundal: deep, open water to dark for PSN d) Benthic: bottom area

  23. Fig. 8-16, p. 182

  24. 6) Some Lakes Have More Nutrients Than Others a) Oligotrophic: poorly nourished, usually have deep with steep banks, usually clear with small populations b) Eutrophic: large supply of nutrients, usually shallow, have murky brown or green waterhigh NPP c) Mesotrophic: between the 2 d) Cultural Eutrophication: increasing the rate of eutrophication due to input from urban & agricultural areas

  25. Stepped Art Fig. 8-17, p. 182

  26. 7) Freshwater Streams and Rivers a) Surface water, becomes runoff when it flows into streams b) Watershed (drainage basin): land area that drains into a specific stream or river c) River zones (page 176) 1. Source: Cold mountain water 2. Transition: wider, deeper and warmer streams down gentler slopes 3. Flood plain: even wider, flow over flat valley

  27. Fig. 8-18, p. 183

  28. Case Study: Dams, Deltas, Wetlands, Hurricanes, and New Orleans • Coastal deltas, mangrove forests, and coastal wetlands: natural protection against storms • Dams and levees reduce sediments in deltas: significance? • New Orleans, Louisiana, and Hurricane Katrina: August 29, 2005 • Global warming, sea rise, • and New Orleans

  29. Fig. 8-19, p. 178

  30. 8) Freshwater Inland Wetlands Are Vital Sponges a) Land covered with freshwater all or part of the time b) Types 1. Marsh: grass and reeds with few trees 2. Swamps: mostly trees 3. Prairie pothole: depression left by glaciers 4. Flood plain: during rainy season 5. Arctic tundra: during the summer

  31. c) Highly productive & provide habitats for many species d) Provide free ecological and economic services • Filter and degrade toxic wastes • Reduce flooding and erosion • Help to replenish streams and recharge groundwater aquifers • Biodiversity • Food and timber • Recreation areas

  32. 8-5 How Have Human Activities Affected Freshwater Ecosystems? 1) Dams & Canals fragment 40% of world’s 237 large rivers. Destroy habitats by reducing water flow, cause floods and increase damage by storms 2) Flood control levees & dikes: disconnect the rivers from flood plains, destroy habitats alter or reduce the functions of wetlands 3) Addition of pollutants by cities and farms 4) Draining or filling of wetlands for crops or buildings

  33. Case Study: Inland Wetland Losses in the United States (page 179) • Loss of wetlands has led to • Increased flood and drought damage • Lost due to • Growing crops • Mining • Forestry • Oil and gas extraction • Building highways • Urban development

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