1. Chapter 7
Aquatic Biodiversity

2. APES students will discuss the aquatic biodiversity to develop an experiment to test the effects of parasites on an ecosystem.

3. Core Case Study: Why Should We Care About Coral Reefs?
Coral reefs form in clear, warm coastal waters of the tropics and subtropics.
Formed by massive colonies of polyps.
Figure 6-1

4. Core Case Study: Why Should We Care About Coral Reefs?
Help moderate atmospheric temperature by removing CO2 from the atmosphere.
Act as natural barriers that help protect 14% of the world’s coastlines from erosion by battering waves and storms.
Provide habitats for a variety of marine organisms.

5. AQUATIC ENVIRONMENTS aquatic life zones = terrestrial biomes
Saltwater and freshwater aquatic life zones cover almost ______% of the earth’s surface
Figure 6-2

6. What percent of the Earth’s H2O is freshwater? What percent is potable?
Figure 6-3

7. What Kinds of Organisms Live in Aquatic Life Zones?
Aquatic systems contain floating, drifting, swimming, bottom-dwelling, and decomposer organisms.
Plankton: important group of weakly swimming, free-floating biota.
Phytoplankton (plant), Zooplankton (animal), Ultraplankton (photosynthetic bacteria)
Necton: fish, turtles, whales.
Benthos: bottom dwellers (barnacles, oysters).
Decomposers: breakdown organic compounds (mostly bacteria).

8. Life in Layers
Life in most aquatic systems is found in surface, middle, and bottom layers.
Temperature, access to sunlight for photosynthesis, dissolved oxygen content, nutrient availability changes with depth.
Euphotic zone (upper layer in deep water habitats): sunlight can penetrate.

9. SALTWATER LIFE ZONES
The oceans that occupy most of the earth’s surface provide many ecological and economic services.
Figure 6-4

10. The Coastal Zone: Where Most of the Action Is
The coastal zone: the warm, nutrient-rich, shallow water that extends from the high-tide mark on land to the gently sloping, shallow edge of the continental shelf.
The coastal zone makes up less than __% of the world’s ocean area but contains __% of all marine species.
Provides numerous ecological and economic services.
Subject to human disturbance.

11. The Coastal Zone
Figure 6-5

12. Marine Ecosystems
Scientists estimate that marine systems provide $21 trillion in goods and services per year __% more than terrestrial ecosystems.
Figure 6-4

13. Estuaries and Coastal Wetlands: Centers of Productivity
Estuaries include river mouths, inlets, bays, sounds, salt marshes in temperate zones and mangrove forests in tropical zones.
Figure 6-7

14. Mangrove Forests
Are found along about 70% of gently sloping sandy and silty coastlines in tropical and subtropical regions.
Figure 6-8

15. Estuaries and Coastal Wetlands: Centers of Productivity
Estuaries and coastal marshes provide ecological and economic services.
Filter toxic pollutants, excess plant nutrients, sediments, and other pollutants.
Reduce storm damage by absorbing waves and storing excess water produced by storms and tsunamis.
Provide food, habitats and nursery sites for many aquatic species.

16. Rocky and Sandy Shores: Living with the Tides
Organisms experiencing daily low and high tides have evolved a number of ways to survive under harsh and changing conditions.
Gravitational pull by moon and sun causes tides.
Intertidal Zone: area of shoreline between low and high tides.

17. Rocky and Sandy Shores: Living with the Tides
Organisms in intertidal zone develop specialized niches to deal with daily changes in:
Temperature
Salinity
Wave action
Figure 6-9

18. What is a barrier island?
More than half of all barrier islands have been developed.
Folly Beach
Why are barrier islands important?

19. Barrier Islands
Low, narrow, sandy islands that form offshore from a coastline.
Primary and secondary dunes on gently sloping sandy barrier beaches protect land from erosion by the sea.
Figure 6-10

20. Threats to Coral Reefs: Increasing Stresses
Biologically diverse and productive coral reefs are being stressed by human activities.
Figure 6-11

21. Natural Capital Degradation
Coral Reefs
Ocean warming
Soil erosion
Algae growth from fertilizer runoff
Mangrove destruction
Bleaching
Rising sea levels
Increased UV exposure
Damage from anchors
Damage from fishing and diving
Figure 6.12
Natural capital degradation: major threats to coral reefs. QUESTION: Which three of these threats do you think are the most serious?
Fig. 6-12, p. 135

22. Only ~2.5% of all the water on our planet is freshwater, however, ____________.
Most of this is in large freshwater lakes.
Most of this is far from where humans live
Most of this is in underground aquifers
Over half of this is extremely hard water and is nearly unusable for drinking or agriculture
Over half of this is in wetlands near coastlines and is becoming contaminated with saltwater

23. Marine biologists have estimated that about ___ of the world’s coral reefs have been destroyed by human activities. 5%
10%
15%
25%
40%

24. Most of the wetlands that are lost are used for
Mining
Urban development
Agriculture
Forestry
Recreation

25. Defining characteristics of a wetland involve which of the following?
Hydrology
Soil Type
Species composition
I only
II only
I and II only
II and III only
I, II, and III

26. Which of the following illustrations does not match the accompanying ecological concept?
Coral reefs have high biodiversity
Estuaries have high productivity
DO is a primary limiting factor in the upper layer of a stratified lake
The open ocean is the least productive of aquatic life zones
Littoral zones have high biodiversity

27. Design a controlled experiment to see if an introduced bird parasite is negatively affecting the shrimp population.

28. Biological Zones in the Open Sea: Light Rules
Euphotic zone: brightly lit surface layer.
Nutrient levels low, dissolved O2 high, photosynthetic activity.
Bathyal zone: dimly lit middle layer.
No photosynthetic activity, zooplankton and fish live there and migrate to euphotic zone to feed at night.
Abyssal zone: dark bottom layer.
Very cold, little dissolved O2.

29. FRESHWATER LIFE ZONES Freshwater life zones include:
Standing (lentic) water such as lakes, ponds, and inland wetlands.
Flowing (lotic) systems such as streams and rivers.
Figure 6-14

30. Lakes: Water-Filled Depressions
Lakes are large natural bodies of standing freshwater formed from precipitation, runoff, and groundwater seepage consisting of:
Littoral zone (near shore, shallow, with rooted plants).
Limnetic zone (open, offshore area, sunlit).
Profundal zone (deep, open water, too dark for photosynthesis).
Benthic zone (bottom of lake, nourished by dead matter).

31. Lakes: Water-Filled Depressions
During summer and winter in deep temperate zone lakes the become stratified into temperature layers and will overturn.
This equalizes the temperature at all depths.
Oxygen is brought from the surface to the lake bottom and nutrients from the bottom are brought to the top.
What causes this overturning?

32. Effects of Plant Nutrients on Lakes: Too Much of a Good Thing
Plant nutrients from a lake’s environment affect the types and numbers of organisms it can support.
Figure 6-16

33. Effects of Plant Nutrients on Lakes: Too Much of a Good Thing
Plant nutrients from a lake’s environment affect the types and numbers of organisms it can support.
Oligotrophic (poorly nourished) lake: Usually newly formed lake with small supply of plant nutrient input.
Eutrophic (well nourished) lake: Over time, sediment, organic material, and inorganic nutrients wash into lakes causing excessive plant growth.

34. Effects of Plant Nutrients on Lakes: Too Much of a Good Thing
Cultural eutrophication:
Human inputs of nutrients from the atmosphere and urban and agricultural areas can accelerate the eutrophication process.

35. Freshwater Streams and Rivers: From the Mountains to the Oceans
Water flowing from mountains to the sea creates different aquatic conditions and habitats.
Figure 6-17

36. Case Study: Dams, Wetlands, Hurricanes, and New Orleans
Dams and levees have been built to control water flows in New Orleans.
Reduction in natural flow has destroyed natural wetlands.
Causes city to lie below sea-level (up to 3 meters).
Global sea levels have risen almost 0.3 meters since 1900.
Where is world’s largest dam

37. Freshwater Inland Wetlands: Vital Sponges
Inland wetlands act like natural sponges that absorb and store excess water from storms and provide a variety of wildlife habitats.
Figure 6-18

38. Freshwater Inland Wetlands: Vital Sponges
Filter and degrade pollutants.
Reduce flooding and erosion by absorbing slowly releasing overflows.
Help replenish stream flows during dry periods.
Help recharge ground aquifers.
Provide economic resources and recreation.

39. Impacts of Human Activities on Freshwater Systems
Dams, cities, farmlands, and filled-in wetlands alter and degrade freshwater habitats.
Dams, diversions and canals have fragmented about 40% of the world’s 237 large rivers.
Flood control levees and dikes alter and destroy aquatic habitats.
Cities and farmlands add pollutants and excess plant nutrients to streams and rivers.
Many inland wetlands have been drained or filled for agriculture or (sub)urban development.

40. Impacts of Human Activities on Freshwater Systems
These wetlands have been ditched and drained for cropland conversion.
Figure 6-19

41. The twilight (dimly lit) zone of the sea is the
A. Abyssal zone
B. Euphotic zone
C. Bathyal zone
D. Costal zone
E. Benthic zone

42. Lakes are large natural bodies of standing water found in depressions.
These depressions can be formed by
Glaciation
Earthquakes
Volcanic activity
Erosion
All of the above

43. Which of the following is the zone of a pond or lake in which rooted, emergent plants such as cattails and rushes are located?
Benthic
Limnetic
Littoral
Profundal
Riparian

44. Lake overturns bring
Oxygen and nutrients to the surface
Oxygen and nutrients to the lake bottom
Oxygen to the surface and nutrients to the lake bottom
Oxygen to the lake bottom and nutrients to the surface

45. Which of the following regions of the ocean is least likely to contain photosynthetic organisms?
Intertidal zone
Zone of coastal upwelling
Pelagic zone
Euphotic zone
Abyssal zone

46. Which of the following elements is most likely to limit primary production in fresh water lakes?
Oxygen
Calcium
Phosphorus
Carbon
Iron