MILLER/SPOOLMAN 17 TH LIVING IN THE ENVIRONMENT. Chapter 8 Aquatic Biodiversity

Transcription

1 MILLER/SPOOLMAN LIVING IN THE ENVIRONMENT 17 TH Chapter 8 Aquatic Biodiversity

2 Core Case Study: Why Should We Care about Coral Reefs? (1) Biodiversity Formation Tiny animals (polyps) and algae have mutualistic relationship Polyps secret calcium carbonate shells, which become coral reefs

3 Core Case Study: Why Should We Care about Coral Reefs? (2) 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

4 Core Case Study: Why Should We Care about Coral Reefs? (3) Degradation and decline Coastal development Pollution Overfishing Warmer ocean temperatures leading to coral bleaching: kill algae and thus the polyps Increasing ocean acidity

5 A Healthy Coral Reef in the Red Sea Fig. 8-1, p. 168

6 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.

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

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

9 The Ocean Planet Fig. 8-2, p. 169

10 Ocean hemisphere Land ocean hemisphere Fig. 8-2, p. 169

11 Aquatic Systems Fig. 8-3, p. 170

12 Most Aquatic Species Live in Top, Middle, or Bottom Layers of Water (1) Plankton: free floating Phytoplankton Primary producers for most aquatic food webs Zooplankton Primary and secondary consumers Single-celled to large invertebrates like jellyfish Ultraplankton Tiny photosynthetic bacteria

13 Most Aquatic Species Live in Top, Middle, or Bottom Layers of Water (2) Nekton Strong swimmers: fish, turtles, whales Benthos Bottom dwellers: oysters, sea stars, clams, lobsters, crabs Decomposers Mostly bacteria

14 Most Aquatic Species Live in Top, Middle, or Bottom Layers of Water (3) 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 (photic) zone Turbidity: degree of cloudiness in water Inhibits photosynthesis

15 Four Types of Aquatic Life Forms Fig. 8-4, p. 171

16 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.

17 Oceans Provide Vital Ecological and Economic Resources Estimated $12 trillion per year in goods and services Reservoirs of diversity in three major life zones 1. Coastal zone Warm, nutrient rich, shallow Shore to edge of continental shelf Usually high NPP from ample sunlight and nutrients 2. Open sea 3. Ocean bottom

18 Major Ecological and Economic Services Provided by Marine Systems Fig. 8-5, p. 172

19 Natural Capital Marine Ecosystems Ecological Services Climate moderation CO 2 absorption Nutrient cycling Waste treatment Reduced storm impact (mangroves, barrier islands, coastal wetlands) Habitats and nursery areas Genetic resources and biodiversity Scientific information Economic Services Food Animal and pet feed Pharmaceuticals Harbors and transportation routes Coastal habitats for humans Recreation Employment Oil and natural gas Minerals Building materials Fig. 8-5, p. 172

20 Major Life Zones and Vertical Zones in an Ocean Fig. 8-6, p. 173

21 Darkness Twilight Photosynthesis High tide Low tide Coastal Zone Open Sea Sea level Depth in meters 0 Estuarine Zone Continental shelf Euphotic Zone Bathyal Zone 500 1,000 1,500 Water temperature drops rapidly between the euphotic zone and the abyssal zone in an area called the thermocline. Abyssal Zone 2,000 3,000 4,000 5,000 10, Water temperature ( C) Fig. 8-6, p. 173

22 Estuaries and Coastal Wetlands Are Highly Productive (1) Estuaries and coastal wetlands Where rivers meet the sea Seawater mixes with freshwater Very productive ecosystems: high nutrient levels River mouths Inlets Bays Sounds Salt marshes Mangrove forests

23 View of an Estuary from Space Fig. 8-7, p. 173

24 Coastal Marsh Ecosystem Fig. 8-8, p. 174

25 Herring gulls Peregrine falcon Cordgrass Snowy egret Short-billed dowitcher Phytoplankton Marsh periwinkle Smelt Zooplankton and small crustaceans Soft-shelled clam Bacteria Clamworm Producer to primary consumer Primary to Secondary to secondary consumer higher-level consumer All consumers and producers to decomposers Fig. 8-8a, p. 174

26 Estuaries and Coastal Wetlands Are Highly Productive (2) Seagrass Beds Grow underwater in shallow areas Support a variety of marine species Stabilize shorelines Reduce wave impact Mangrove forests Along tropical and subtropical coastlines 69 different tree species that grow in saltwater

27 See Grass Bed Organisms Fig. 8-9, p. 174

28 Mangrove Forest in Australia Fig. 8-10, p. 175

29 Estuaries and Coastal Wetlands Are Highly Productive (3) 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

30 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

31 Living between the Tides Fig. 8-11, p. 176

32 Rocky Shore Beach Sea star Hermit crab Shore crab High tide Periwinkle Sea urchin Anemone Mussel Sculpin Low tide Nudibranch Monterey flatworm Kelp Barnacles Sea lettuce Fig. 8-11a, p. 176

33 Barrier Beach Beach flea Blue crab Peanut worm Dwarf olive Clam High tide Tiger beetle Silversides Low tide Sandpiper Mole shrimp Ghost shrimp White sand macoma Sand dollar Moon snail Fig. 8-11b, p. 176

34 Rocky Shore Beach Sea star Hermit crab Shore crab High tide Periwinkle Sea urchin Anemone Mussel Sculpin Low tide Monterey flatworm Kelp Sea lettuce Beach flea Barnacles Barrier Beach Nudibranch Peanut worm Blue crab Dwarf olive Clam High tide Tiger beetle Sandpiper Silversides Low tide Mole shrimp Ghost shrimp White sand macoma Sand dollar Moon snail Stepped Art Fig. 8-11, p. 176

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

36 Natural Capital: Some Components and Interactions in a Coral Reef Ecosystem Fig. 8-12, p. 177

37 Gray reef shark Sea nettle Green sea turtle Blue tang Fairy basslet Parrot fish Hard corals Symbiotic algae Algae Phytoplankton Brittle star Sergeant major Banded coral shrimp Coney Zooplankton Blackcap basslet Sponges Moray eel Bacteria Producer to primary consumer Primary to secondary Secondary to consumer higher-level consumer All producers and consumers to decomposers Fig. 8-12, p. 177

38 The Open Sea and Ocean Floor Host a Variety of Species (1) Three vertical zones of the open sea 1. Euphotic zone Phytoplankton Nutrient levels low Dissolved oxygen levels high 2. Bathyal zone Dimly lit Zooplankton and smaller fishes

39 The Open Sea and Ocean Floor Host a Variety of Species (2) 3. Abyssal zone Dark and cold High levels of nutrients Little dissolved oxygen Deposit feeders Filter feeders Upwelling brings nutrients to euphotic zone Primary productivity and NPP

40 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.

41 Human Activities Are Disrupting and Degrading Marine Systems Major threats to marine systems Coastal development Overfishing Use of fishing trawlers 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

42 Major Human Impacts on Marine Ecosystems and Coral Reefs Fig. 8-13, p. 179

43 Natural Capital Degradation Major Human Impacts on Marine Ecosystems and Coral Reefs Marine Ecosystems Coral Reefs Half of coastal wetlands lost to agriculture and urban development Over one-fifth of mangrove forests lost to agriculture, development, and shrimp farms since 1980 Beaches eroding because of coastal development and rising sea levels Ocean bottom habitats degraded by dredging and trawler fishing Ocean warming Rising ocean acidity Soil erosion Algae growth from fertilizer runoff Bleaching Rising sea levels Increased UV exposure Damage from anchors At least 20% of coral reefs severely damaged and Damage from fishing and diving 25 33% more threatened Fig. 8-13, p. 179

44 Case Study: The Chesapeake Bay an Estuary in Trouble (1) Largest estuary in the US; polluted since 1960 Human population increased Point and nonpoint sources raised pollution Phosphate and nitrate levels too high Excess sediments from runoff and decreased vegetation

45 Case Study: The Chesapeake Bay an Estuary in Trouble (2) Oysters, a keystone species, greatly reduced 1983: Chesapeake Bay Program Integrated coastal management with local, state, federal governments and citizens groups 2008 update: 25 years and $6 billion Program met only 21% of goals Water quality very poor

46 Chesapeake Bay Fig. 8-14, p. 180

47 Drainage basin No oxygen Low concentrations of oxygen Fig. 8-14, p. 180

48 8-4 Why Are Freshwater Ecosystems Important? Concept 8-4 Freshwater ecosystems provide major ecological and economic services, and are irreplaceable reservoirs of biodiversity.

49 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

50 Water Stands in Some Freshwater Systems and Flows in Others (2) Four zones based on depth and distance from shore 1. Littoral zone Near shore where rooted plants grow High biodiversity Turtles, frogs, crayfish, some fish 2. Limnetic zone Open, sunlight area away from shore Main photosynthetic zone Some larger fish

51 Water Stands in Some Freshwater Systems and Flows in Others (3) 3. Profundal zone Deep water too dark for photosynthesis Low oxygen levels Some fish 4. Benthic zone Decomposers Detritus feeders Some fish Nourished primarily by dead matter

52 Major Ecological and Economic Services Provided by Freshwater Systems Fig. 8-15, p. 181

53 Natural Capital Freshwater Systems Ecological Services Economic Services Climate moderation Nutrient cycling Waste treatment Flood control Groundwater recharge Habitats for many species Genetic resources and biodiversity Scientific information Food Drinking water Irrigation water Hydroelectricity Transportation corridors Recreation Employment Fig. 8-15, p. 181

54 Distinct Zones of Life in a Fairly Deep Temperate Zone Lake Fig. 8-16, p. 182

55 Painted turtle Blue-winged teal Green frog Muskrat Pond snail Littoral zone Plankton Diving beetle Northern pike Yellow perch Bloodworms Fig. 8-16, p. 182

56 Some Lakes Have More Nutrients Oligotrophic lakes Than Others Low levels of nutrients and low NPP Very clear water Eutrophic lakes High levels of nutrients and high NPP Murky water with high turbidity Mesotrophic lakes Cultural eutrophication of lakes from human input of nutrients

57 The Effect of Nutrient Enrichment on a Lake Fig. 8-17, p. 182

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

59 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

60 Three Zones in the Downhill Flow of Water Fig. 8-18, p. 183

61 Lake Rain and snow Glacier Headwaters Rapids Waterfall Tributary Flood plain Oxbow lake Salt marsh Delta Deposited sediment Source Zone Ocean Transition Zone Floodplain Zone Sediment Water Fig. 8-18, p. 183

62 Rain and snow Lake Glacier Rapids Waterfall Tributary Flood plain Oxbow lake Salt marsh Delta Deposited sediment Source Zone Ocean Transition Zone Floodplain Zone Water Sediment Stepped Art Fig. 8-18, p. 183

63 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

64 New Orleans, Louisiana Flooded by Hurricane Katrina Fig. 8-19, p. 185

65 Projection of New Orleans if the Sea Level Rises 0.9 Meter Fig. 8-20, p. 185

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

67 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

68 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.

69 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 streams, rivers, and lakes Impact of drained wetlands

70 Three Big Ideas 1. Saltwater and freshwater aquatic life zones cover almost three-fourths of the earth s surface, and oceans dominate the planet. 2. The earth s aquatic systems provide important ecological and economic services. 3. Human activities threaten biodiversity and disrupt ecological and economic services provided by aquatic systems.