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
Covers 71% of the Earth’s surface
Freshwater- covers 2.2% of the Earth’s surface

7. Most of the Earth Is Covered with Water (2)
Aquatic life zones- equivalent to biomes
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- free floating
Phytoplankton- producers
Zooplankton- consumers
Ultraplankton- photosynthetic bacteria
Nekton- free swimming- fish, turtles, whales
Benthos- bottom dwellers
Decomposers- mostly bacteria

12. dinoflagellate
radiolarian

13. Shrimp larva
Anemone larva
Worm larva
Worm larva
copepod

17. 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
Depth of the euphotic zone can be decreased by turbidity- (cloudiness)

18. Ted video

19. 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.

20. Major Ecological and Economic Services Provided by Marine Systems

21. Oceans Provide Important Ecological and Economic Resources
Reservoirs of diversity in three major life zones
Coastal zone- warm, nutrient rich, shallow water from high tide mark to the edge of the continental shelf
Makes up less than 10% of ocean area, but holds 90% of species
Usually high NPP- due to high nutrients and sunlight
Open sea-
Ocean bottom

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

23. Euphotic Zone Continental shelf
High tide
Low tide
Sun
Depth in meters
Coastal Zone
Open Sea
Sea level
Photosynthesis 50
Euphotic Zone
Estuarine Zone
100
Continental shelf
200
500
Bathyal Zone
Twilight
1,000
1,500
2,000
Water temperature drops rapidly between the euphotic zone and the abyssal zone in an area called the thermocline .
Abyssal Zone
3,000
Figure 8.5
Natural capital: major life zones and vertical zones (not drawn to scale) in an ocean. Actual depths of zones may vary. Available light determines the euphotic, bathyal and abyssal zones. Temperature zones also vary with depth, shown here by the red curve. Question: How is an ocean like a rain forest? (Hint: see Figure 7-17, p. 156.)
Darkness
4,000
5,000
10,000 5 10 15 20 25 30
Water temperature (°C)
Fig. 8-5, p. 166

24. Estuaries and Coastal Wetlands Are Highly Productive (1)
Estuaries and coastal wetlands(where fresh and salt water combine)
River mouths
Inlets
Bays
Sounds
Salt marshes
Mangrove forests
Seagrass Beds
Support a variety of marine species
Stabilize shorelines
Reduce wave impact

25. 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

26. View of an Estuary from Space

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

28. Figure 8.7
Some components and interactions in a salt marsh ecosystem in a temperate area such as the United States. When these organisms die, decomposers break down their organic matter into minerals used by plants. Colored arrows indicate transfers of matter and energy between consumers (herbivores), secondary or higher-level consumers (carnivores), and decomposers. Organisms are not drawn to scale. The photo shows a salt marsh in Peru.
Fig. 8-7b, p. 167

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

30. Rocky and Sandy Shores Host Different Types of Organisms
Intertidal zone- area of shoreline between high and low tide
Rocky shores- lots of species, seasonal changes in salinity, temperature and water flow
Sandy shores: barrier beaches
Organism adaptations necessary to deal with daily salinity and moisture changes- digging, burrowing, tunneling
Importance of sand dunes- protect from erosion

31. Living between the Tides

32. Primary and Secondary Dunes

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

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

35. The Open Sea and Ocean Floor Host a Variety of Species
Vertical zones of the open sea
Euphotic zone- brightly lit- phytoplankton carry out 40% of the worlds photosynthesis
Bathyal zone- dimly lit middle zone
Abyssal zone: receives marine snow
Deposit feeders
Filter feeders
Upwellings- bring nutrients from the bottom to the surface
Primary productivity and NPP- low per unit area- high NPP contribution for the earth

36. Animation: Ocean provinces

37. 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.

38. 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

39. 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

40. 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? 40

41. Chesapeake Bay

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- top, near the shore, full light,
Limnetic zone- open, sunlit, away from shore
Profundal zone-deep open water, too dark for photosynthesis
Benthic zone-bottom- decomposers, detritus feeders, some fish

45. NATURAL CAPITAL Freshwater Systems Ecological Services
Economic Services
Climate moderation
Food
Nutrient cycling
Drinking water
Waste treatment
Irrigation water
Flood control
Hydroelectricity
Figure 8.14
Major ecological and economic services provided by freshwater systems (Concept 8-4). Question: Which two ecological services and which two economic services do you think are the most important? Why?
Groundwater recharge
Habitats for many species
Transportation corridors
Genetic resources and biodiversity
Recreation
Scientific information
Employment
Fig. 8-14, p. 174

46. Sunlight Blue-winged teal Painted turtle Green frog Muskrat Pond snail
Littoral zone
Plankton
Figure 8.15
Distinct zones of life in a fairly deep temperate zone lake. See an animation based on this figure at CengageNOW. Question: How are deep lakes like tropical rain forests? (Hint: See Figure 7-17, p. 156)
Limnetic zone
Diving beetle
Profundal zone
Northern pike
Benthic zone
Yellow perch
Bloodworms
Fig. 8-15, p. 175

47. Some Lakes Have More Nutrients Than Others
Oligotrophic lakes
Deep lakes, steep sides, 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. The Effect of Nutrient Enrichment on a Lake

49. Freshwater Streams and Rivers Carry Water from the Mountains to the Oceans
Surface water- precip that does not sink or evaporate
Runoff- surface water that flows into streams
Watershed, drainage basin- land area that delivers run-off, sediment and dissolved substances to a stream

50. Three aquatic life zones
Source zone-mountain head waters, shallow, swiftly moving streams- cold, clear- lots of dissolved oxygen- not very productive due to low nutrients
Transition zone- wider, deeper, warmer streams that flow down gentler slopes, more turbid- less DO- more productivity

51. Floodplain zone- wide, deep rivers that flow across flat valleys, supports large populations of producers- full of silt-

52. Three Zones in the Downhill Flow of Water

53. 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

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

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

56. Freshwater Inland Wetlands Are Vital Sponges (1)
Marshes- dominated by grasses and few trees
Swamps- trees and shrubs
Prairie potholes-depressions carved out by ancient glaciers
Floodplains- receive excessive water during heavy rains and floods
Arctic tundra in summer

57. 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

58. Active Figure: Lake zonation

59. Animation: Trophic natures of lakes

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
dams and canals on rivers
flood control levees and dikes along rivers
pollutants from cities and farms on rivers
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