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 businesses
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. A Healthy Coral Reef in the Red Sea

5. 8-1 What Is the General Nature of Aquatic Systems?
Concept 8-1A Saltwater and freshwater aquatic life zones cover almost three-fourths of the earth’s surface with oceans dominating the planet.
Concept 8-1B The key factors determining biodiversity in aquatic systems are temperature, dissolved oxygen content, availability of food and availability of light and nutrients necessary for photosynthesis.

6. Most of the Earth Is Covered with Water (1)
Saltwater: global ocean divided into 4 areas
Atlantic
Pacific
Arctic
Indian
Freshwater

7. Most of the Earth Is Covered with Water (2)
Aquatic life zones
Saltwater: marine
Oceans and estuaries
Coastlands and shorelines
Coral reefs
Mangrove forests
Freshwater
Lakes
Rivers and streams
Inland wetlands

8. The Ocean Planet

9. Distribution of the World’s Major Saltwater and Freshwater Sources

10. Most Aquatic Species Live in Top, Middle, or Bottom Layers of Water (1)
Plankton
Phytoplankton
Zooplankton
Ultraplankton
Nekton
Benthos
Decomposers

11. Most Aquatic Species Live in Top, Middle, or Bottom Layers of Water (2)
Key factors in the distribution of organisms
Temperature
Dissolved oxygen content
Availability of food
Availability of light and nutrients needed for photosynthesis in the euphotic, or photic, zone

12. 8-2 Why Are Marine Aquatic Systems Important?
Concept 8-2 Saltwater ecosystems are irreplaceable reservoirs of biodiversity and provide major ecological and economic services.

13. Oceans Provide Important Ecological and Economic Resources
Reservoirs of diversity in three major life zones
Coastal zone
Usually high NPP
Open sea
Ocean bottom

14. Major Ecological and Economic Services Provided by Marine Systems

15. Natural Capital: Major Life Zones and Vertical Zones in an Ocean

16. Estuaries and Coastal Wetlands Are Highly Productive (1)
River mouths
Inlets
Bays
Sounds
Salt marshes
Mangrove forests
Seagrass Beds
Support a variety of marine species
Stabilize shorelines
Reduce wave impact

17. Estuaries and Coastal Wetlands Are Highly Productive (2)
Important ecological and economic services
Coastal aquatic systems maintain water quality by filtering
Toxic pollutants
Excess plant nutrients
Sediments
Absorb other pollutants
Provide food, timber, fuelwood, and habitats
Reduce storm damage and coast erosion

18. View of an Estuary from Space

19. Some Components and Interactions in a Salt Marsh Ecosystem in a Temperate Area

20. Mangrove Forest in Daintree National Park in Queensland, Australia

21. Rocky and Sandy Shores Host Different Types of Organisms
Intertidal zone
Rocky shores
Sandy shores: barrier beaches
Organism adaptations necessary to deal with daily salinity and moisture changes
Importance of sand dunes

22. Rocky Shore Beach Barrier Beach Sea star Hermit crab Shore crab
High tide
Periwinkle
Sea urchin
Anemone
Mussel
Low tide
Sculpin
Barnacles
Kelp
Sea lettuce
Monterey flatworm
Nudibranch
Beach flea
Peanut worm
Tiger beetle
Barrier Beach
Blue crab
Clam
Dwarf olive
High tide
Sandpiper
Ghost shrimp
Silversides
Low tide
Mole shrimp
White sand macoma
Sand dollar
Moon snail
Figure 8.9
Living between the tides. Some organisms with specialized niches found in various zones on rocky shore beaches (top) and barrier or sandy beaches (bottom). Organisms are not drawn to scale.
Stepped Art
Fig. 8-9, p. 169

23. Primary and Secondary Dunes
Figure 8.10
Primary and secondary dunes on gently sloping sandy barrier beaches help protect land from erosion by the sea. The roots of grasses that colonize the dunes hold the sand in place. Ideally, construction is allowed only behind the second strip of dunes, and walkways to the ocean beach are built so as not to damage the dunes. This helps to preserve barrier beaches and to protect buildings from damage by wind, high tides, beach erosion, and flooding from storm surges. Such protection is rare in some coastal areas because the short-term economic value of oceanfront land is considered much higher than its long-term ecological value. Rising sea levels from global warming may put many barrier beaches under water by the end of this century. Question: Do you think that the long and short-term ecological values of oceanfront dunes outweigh the short-term economic value of removing them for coastal development? Explain.

24. Coral Reefs Are Amazing Centers of Biodiversity
Marine equivalent of tropical rain forests
Habitats for one-fourth of all marine species

25. Natural Capital: Some Components and Interactions in a Coral Reef Ecosystem

26. The Open Sea and Ocean Floor Host a Variety of Species
Vertical zones of the open sea
Euphotic zone
Bathyal zone
Abyssal zone: receives marine snow
Deposit feeders
Filter feeders
Upwellings
Primary productivity and NPP

27. Animation: Ocean provinces

28. Video: Elephant seals

29. Video: Florida reefs

30. Video: Giant clam

31. Video: Reef fish (Bahamas)

32. Video: Schooling fish

33. Video: Sea anemones

34. Video: Sea lions

35. Video: Sting rays

36. 8-3 How Have Human Activities Affected Marine Ecosystems?
Concept 8-3 Human activities threaten aquatic biodiversity and disrupt ecological and economic services provided by saltwater systems.

37. Human Activities Are Disrupting and Degrading Marine Systems
Major threats to marine systems
Coastal development
Overfishing
Runoff of nonpoint source pollution
Point source pollution
Habitat destruction
Introduction of invasive species
Climate change from human activities
Pollution of coastal wetlands and estuaries

38. Case Study: The Chesapeake Bay—an Estuary in Trouble (1)
Largest estuary in the US; polluted since 1960
Population increased
Point and nonpoint sources raised pollution
Phosphate and nitrate levels too high

39. Case Study: The Chesapeake Bay—an Estuary in Trouble (2)
Overfishing
1983: Chesapeake Bay Program
Update on recovery of the Bay
Should we introduce an Asian oyster? 39

40. Chesapeake Bay

41. Video: ABC News: Beach pollution

42. 8-4 Why Are Freshwater Ecosystems Important?
Concept 8-4 Freshwater ecosystems provide major ecological and economic services and are irreplaceable reservoirs of biodiversity.

43. Water Stands in Some Freshwater Systems and Flows in Others (1)
Standing (lentic) bodies of freshwater
Lakes
Ponds
Inland wetlands
Flowing (lotic) systems of freshwater
Streams
Rivers

44. Water Stands in Some Freshwater Systems and Flows in Others (2)
Formation of lakes
Four zones based on depth and distance from shore
Littoral zone
Limnetic zone
Profundal zone
Benthic zone

45. Major Ecological and Economic Services Provided by Freshwater Systems

46. Distinct Zones of Life in a Fairly Deep Temperate Zone Lake

47. Some Lakes Have More Nutrients Than Others
Oligotrophic lakes
Low levels of nutrients and low NPP
Eutrophic lakes
High levels of nutrients and high NPP
Mesotrophic lakes
Cultural eutrophication leads to hypereutrophic lakes

48. Figure 8.16
The effect of nutrient enrichment on a lake. Crater Lake in the U.S. state of Oregon (left) is an example of an oligotrophic lake that is low in nutrients. Because of the low density of plankton, its water is quite clear. The lake on the right, found in western New York State, is a eutrophic lake. Because of an excess of plant nutrients, its surface is covered with mats of algae and cyanobacteria.
Figure 8.16
The effect of nutrient enrichment on a lake. Crater Lake in the U.S. state of Oregon (left) is an example of an oligotrophic lake that is low in nutrients. Because of the low density of plankton, its water is quite clear. The lake on the right, found in western New York State, is a eutrophic lake. Because of an excess of plant nutrients, its surface is covered with mats of algae and cyanobacteria.
Stepped Art
Fig. 8-16a, p. 175

49. Freshwater Streams and Rivers Carry Water from the Mountains to the Oceans
Surface water
Runoff
Watershed, drainage basin
Three aquatic life zones
Source zone
Transition zone
Floodplain zone

50. Lake Rain and snow Glacier Rapids Waterfall Tributary Flood plain
Source Zone
Transition Zone
Tributary
Flood plain
Oxbow lake
Salt marsh
Delta
Deposited sediment
Ocean
Water
Sediment
Floodplain Zone
Figure 8.17
Three zones in the downhill flow of water: source zone containing mountain (headwater) streams; transition zone containing wider, lower-elevation streams; and floodplain zone containing rivers, which empty into the ocean.
Stepped Art
Fig. 8-17, p. 176

51. 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

52. New Orleans, Louisiana, (U.S.) and Hurricane Katrina

53. Projection of New Orleans if the Sea Level Rises 0.9 Meter

54. Freshwater Inland Wetlands Are Vital Sponges (1)
Marshes
Swamps
Prairie potholes
Floodplains
Arctic tundra in summer

55. Freshwater Inland Wetlands Are Vital Sponges (2)
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

56. Active Figure: Lake zonation

57. Animation: Lake turnover

58. Animation: Trophic natures of lakes

59. Video: River flyover

60. 8-5 How Have Human Activities Affected Freshwater Ecosystems?
Concept 8-5 Human activities threaten biodiversity and disrupt ecological and economic services provided by freshwater lakes, rivers, and wetlands.

61. Human Activities Are Disrupting and Degrading Freshwater Systems
Impact of dams and canals on rivers
Impact of flood control levees and dikes along rivers
Impact of pollutants from cities and farms on rivers
Impact of drained wetlands

62. Case Study: Inland Wetland Losses in the United States
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