1. CHAPTER 8 Aquatic Biodiversity

2. Aquatic life zones Saltwater life zones (marine life zones)
Oceans and estuaries
Coastlands and shorelines
Coral reefs
Mangrove forests

3. Aquatic life zones Freshwater life zones Lakes Rivers and streams
Inland wetlands

4. Aquatic Lifeforms 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
Nekton
Strong swimmers: fish, turtles, whales
Benthos
Bottom dwellers: oysters, sea stars, clams, lobsters, crabs
Decomposers
Mostly bacteria

5. Aquatic life zones 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 zone

6. Turbidity inhibits photosynthesis; decreasing ecosystem productivity
Aquatic life zones
Turbidity
Degree of cloudiness in water from dissolved sediments and nutrients.
Turbidity inhibits photosynthesis; decreasing ecosystem productivity

7. Marine Ecosystems: 3-Major Lifezones
Coastal zone
Warm, nutrient rich, shallow
Shore to edge of continental shelf
Usually high NPP from ample sunlight and nutrients
Open sea
Ocean bottom
Rio de Janeiro, Brazil
Mumbai, India

8. Water temperature (°C)
High tide
Coastal Zone
Open Sea
Low tide
Depth in meters
Sea level
Photosynthesis 50
Euphotic Zone
Estuarine Zone
100
Continental shelf
200
500
Bathyal Zone
Twilight
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
Figure 8.6: This diagram illustrates the 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 line. Question: How is an ocean like a rain forest? (Hint: see Figure 7-15, p. 162.)
Darkness
4,000
5,000
10,000 5 10 15 20 25 30
Water temperature (°C)

9. Estuaries and Coastal Wetlands Are Highly Productive
Where rivers meet the sea & seawater mixes with freshwater
Very productive ecosystems: high nutrient levels
Includes: river mouths, Inlets, Bays, Sounds, saltmarshes, mangrove forests
Important ecological and economic services
Coastal aquatic systems maintain water quality by filtering
pollutants
Excess plant nutrients
Sediments
Reduce storm damage and coast erosion
Provide food and habitats

10. Estuaries and Coastal Wetlands Are Highly Productive
Madagascar; heavy sediment load from soil erosion due to deforestation.

11. Estuaries and Coastal Wetlands Are Highly Productive
Salt Marsh
Coastal temperate climate; most productive ecosystems; often found in estuaries.
Coastal Salt Marsh Ecosystem

12. Estuaries and Coastal Wetlands Are Highly Productive
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 i.e. salt tolerant
Protect coast from erosion
Sheltered habitat for fish and shellfish

13. Mangrove Forest Ecosystem

14. Rocky Shore & Sandy Shores Ecology
Intertidal zone
Rocky shores
Sandy shores: barrier beaches
Living between the Tides
Coastal ecosystems where organisms adaptations help them deal with daily salinity and moisture changes due to high and low tide and subsequent temperature changes.

15. 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

16. Vulnerable because they grow slowly and are disrupted easily
Coral Reefs
Coral Reefs exist in the warm shallow waters just beyond shoreline; most diverse marine biome.
Formation
Result of mutualistic relationship between polyps and algae; algae provide polyp with food, color and oxygen through photosynthesis; algae get a home and some nutrients
Formed by massive colonies of polyps that secrete limestone around their soft body. When polyps die their empty crusts remain as a platform for more reef growth.
Vulnerable because they grow slowly and are disrupted easily

17. Coral Reefs Biodiversity Marine equivalent of tropical rain forests
Habitats for one-fourth of all marine species
Important ecological and economic services
Sequester carbon dioxide i.e. carbon sink
Moderate atmospheric temperatures
Act as natural barriers protecting coasts from erosion (waves and storm surge)
Provide habitats (plus, fish nurseries)
Support fishing and tourism businesses
Provide jobs and building materials

18. Green sea turtle Moray eel
Gray reef shark
Sea nettle
Green sea turtle
Blue tang
Fairy basslet
Parrot fish
Brittle star
Sergeant major
Hard corals
Algae
Banded coral shrimp
Phytoplankton
Coney
Symbiotic algae
Figure 8.12: Natural capital.
This diagram illustrates some of the components and interactions in a coral reef ecosystem. When these organisms die, decomposers break down their organic matter into minerals used by plants. Colored arrows indicate transfers of matter and energy between producers, primary consumers (herbivores), secondary or higher-level consumers (carnivores), and decomposers. Organisms are not drawn to scale.
Zooplankton
Blackcap basslet
Sponges
Moray eel
Bacteria
Producer
to primary consumer
Primary to secondary consumer
Secondary to higher-level consumer
All producers
and consumers
to decomposers

19. Coral Reefs: Degradation & Decline
Coastal development & pollution
Overfishing & destructive fishing practices
Coral Bleaching: warmer ocean temperatures stress algae; they exit polyps leaving behind a white skeleton of calcium carbonate
Ocean acidification: ocean absorbs atmospheric carbon dioxide; reacting with water to produce carbonic acid and excessive hydrogen ions that dissolve shells and inhibit formation of calcium carbonate.

20. Ocean acidification: decrease in the pH and increase in acidity of the oceans, caused by the uptake of anthropogenic carbon dioxide from the atmosphere.
Atmospheric carbon dioxide dissolves in ocean water reacting with water to form carbonic acid; carbonic acid dissociates to yield bicarbonate ions and hydrogen ions; hydrogen ions then react with calcium carbonate of shells and coral skeletons to produce calcium ions and bicarbonate ions. Essentially, free hydrogen ions rip apart calcium carbonate; effectively dissolving and inhibiting the formation of shells and coral.

22. Interconnected Shoreline Ecosystems

23. Ridge-to-Reef Ecosystem Based Management
In Fiji, researchers found that declining forest cover is associated with reduced numbers of freshwater fish species in rivers and streams.
The clearing of forest ecosystems results in heavy soil erosion, and increased sediment loads, in rivers and streams. This coupled with agricultural activity that leads to excessive nutrient loads, from fertilizer, in coastal zones results in turbidity and lack of productivity in rivers, streams, sea-grass beds and coral reefs ecosystems.

24. Three Vertical Lifezones of the Open Sea
Euphotic zone
Phytoplankton
Nutrient levels low
Dissolved oxygen levels high
Bathyal zone
Dimly lit
Zooplankton and smaller fishes
Abyssal zone
Dark and cold
High levels of nutrients
Little dissolved oxygen
Deposit feeders
Filter feeders
Abyssal zone (cont.)
Upwelling brings nutrients to euphotic zone
Primary productivity and NPP

25. Water temperature (°C)
High tide
Coastal Zone
Open Sea
Low tide
Depth in meters
Sea level
Photosynthesis 50
Euphotic Zone
Estuarine Zone
100
Continental shelf
200
500
Bathyal Zone
Twilight
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
Figure 8.6: This diagram illustrates the 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 line. Question: How is an ocean like a rain forest? (Hint: see Figure 7-15, p. 162.)
Darkness
4,000
5,000
10,000 5 10 15 20 25 30
Water temperature (°C)

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

27. 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
Ocean warming
Figure 8.13: This diagram shows the major threats to marine ecosystems (left) and particularly coral reefs (right) (Core Case study) resulting from human activities (Concept 8-3). Questions: Which two of the threats to marine ecosystems do you think are the most serious? Why? Which two of the threats to coral reefs do you think are the most serious? Why?
Rising ocean acidity
Over one-fifth of mangrove forests lost to agriculture, development, and shrimp farms since 1980
Soil erosion
Algae growth from fertilizer runoff
Bleaching
Beaches eroding because of coastal development and rising sea levels
Rising sea levels
Increased UV exposure
Ocean bottom habitats degraded by dredging and trawler fishing
Damage from anchors
Damage from fishing and diving
At least 20% of coral reefs severely damaged and 25–33% more threatened

28. Freshwater Ecosystems

29. Lentic; i.e. Standing bodies of freshwater

30. Lotic; i.e. Flowing systems of freshwater

31. Freshwater Ecosystems
Four zones based on depth and distance from shore
Littoral zone
Near shore where rooted plants grow
High biodiversity
Turtles, frogs, crayfish, some fish
Limnetic zone
Open, sunlight area away from shore
Main photosynthetic zone
Some larger fish

32. Freshwater Ecosystems
Four zones based on depth and distance from shore
Profundal zone
Deep water too dark for photosynthesis
Low oxygen levels
Some fish
Benthic zone
Decomposers
Detritus feeders
Nourished primarily by dead matter

33. Temperate Lake Littoral zone Limnetic zone Profundal zone Benthic zone
Painted turtle
Blue-winged teal
Green frog
Muskrat
Pond snail
Littoral zone
Plankton
Figure 8.16: This diagram illustrates the 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 7-15, p. 162)
Limnetic zone
Profundal zone
Diving beetle
Northern pike
Benthic zone
Yellow perch
Bloodworms

34. Freshwater Ecosystems
Some lakes have more nutrients than others
Oligotrophic lakes
Low levels of nutrients and low NPP
Very clear water
Mesotrophic lakes (meso means middle)
Eutrophic lakes
High levels of nutrients and high NPP due to algal blooms; i.e. growth of algae
Murky water with high turbidity
Eutrophication
Excessive nutrient loads (nitrogen & phosphorous) in a lake or other body of water, due to runoff from the land; causes dense growth of algae and plant life; after plant die-offs, decomposing plant matter uses up oxygen causing fish death.
Cultural eutrophication: eutrophication from human input of nutrients

35. Freshwater Inland Wetlands
Freshwater inland wetlands are vital sponges
Freshwater inland wetlands include:
Marshes
Swamps
Prairie potholes 
Floodplains
Arctic tundra in summer
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

36. Freshwater Inland Wetlands
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, lakes
Impact of drained wetlands

37. Freshwater Ecosystems
Rivers & Streams Carry Water from Mountains to Oceans
Surface water
Surface runoff
Watershed; i.e. drainage basin
Three zones in the downhill flow of water; i.e. aquatic life zones
Source zone
Transition zone
Floodplain zone

38. Waterfall
Lake
Glacier
Rain and snow
Rapids
Source Zone
Transition Zone
Tributary
Flood plain
Oxbow lake
Salt marsh
Delta
Deposited sediment
Ocean
Water
Sediment
Floodplain Zone

39. South Platte River Watershed

40. Mississippi River Drainage Basin

41. Estuaries and Coastal Wetlands Are Important and imperiled
Figure 8.14: The Chesapeake Bay is the largest estuary in the United States. However, the bay is severely degraded as a result of water pollution from point and nonpoint sources in six states and the District of Columbia, and from the atmospheric deposition of air pollutants.

42. Dams, Deltas, Wetlands, Hurricanes, & New Orleans

43. Dams, Deltas, Wetlands, Hurricanes, & New Orleans
Coastal deltas, mangrove forests, and coastal wetlands provide natural protection against storms; slow waves + vegetation and soil absorb water.
Dams and levees reduce sediments in deltas. Sediment is deposited behind dam (upstream) rather than in the river delta; thus reducing size of river delta.
Levees designed to reduce flooding in upstream communities channel water; increasing speed and reducing sediment deposition.

44. Dams, Deltas, Wetlands, Hurricanes, & New Orleans
Without such natural protection many areas of the world (New Orleans, Bangladesh) experience much more severe hurricane impacts due to increased storm surge.
Global warming, sea rise, and New Orleans
Wetland restoration in New Orleans

45. The Chesapeake Bay—an Estuary in Trouble
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
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. Low concentrations of oxygen
Drainage basin
Figure 8.14: The Chesapeake Bay is the largest estuary in the United States. However, the bay is severely degraded as a result of water pollution from point and nonpoint sources in six states and the District of Columbia, and from the atmospheric deposition of air pollutants.
No oxygen
Low concentrations of oxygen