1. 8th Grade Science Quick Review Dana Frank Danao.frank@cms.k12.nc.us

2. 1. Draw a pie chart that represents the distribution of water on earth
1. Draw a pie chart that represents the distribution of water on earth. 2. Why is stewardship of our fresh water vital? Write as many reasons as possible

3. 1.
97% salt
3% fresh
Majority of fresh water in ice caps
& glaciers
Majority of accessible fresh water
found in aquifers 2.
Limited supply of fresh water
Fresh water is not distributed equally on the planet or in the US
Water systems are connected, Contaminated water in one area will end up in another
Toxins in fresh water & salt water can accumulate in food & wild life

4. Describe how water moves in and out of an aquifer.
How do human activities and climate conditions affect an aquifer?

5. 3. Water moves in through recharge zone into aquifer
Water out through wells
Gravity moves water through the aquifer toward oceans or other major water source
Increasing the withdrawal of water from an aquifer by homes and industry lowers the water table. Without recharge (rain), water supply is depleted.
Extreme drought diminishes recharge and lowers water table
Pollution that enters recharge zones (animal waste/farms, landfills, illegal dumping) makes its way to groundwater

6. Aquifers are large reservoirs of ground water
Aquifers are large reservoirs of ground water. These can be accessed by wells, some natural springs bring water out of aquifers through the force of gravity. Water in an aquifer is usually cleaner than surface water, b/c it filters through rocks and sand (recharge area) on it’s way to the aquifer. The water table is the top of the water in an aquifer.

7. Describe how water moves across earth’s surface
Describe how water moves across earth’s surface. Sketching a watershed may help in your description.

8. A watershed is the large area of land the drains waters into streams, that then feed into larger and larger rivers, until draining into a major river. Watersheds are bordered by divides…high areas of land (mtns) that separate one watershed from another

9. Summary 97% of earth’s water is in the oceans
Of the remaining 3% fresh water…most is frozen in glaciers and polar ice caps
The largest % of fresh water is groundwater… aquifers
Fresh water moves across earth’s surface in watersheds/riverbasins

10. Water Quality Indicators The health of a water system is determined by the balance between physical, chemical, and biological variables. Physical variables include temperature, turbidity. Chemical variables include dissolved oxygen and other gases, pH, nitrates and phosphates. Both natural and man-made forces are constantly changing these variables. Biological variables are living organisms.

11. Describe: a) How each of the following indicators affects water quality. b) What may cause each to reach an unhealthy level?
Temperature Turbidity Dissolved Oxygen pH Nitrates and Phosphates

12. Water Quality Indicator Notes Turbidity
Description: Murkiness of water due to suspended particles Levels: Ideal = 1NTU High = 5 NTU+

13. Turbidity Causes: Erosion from construction urban run off
disturbance of stream beds from bottom feeders/livestock
increased algal growth
septic system leaks
decaying plant matter
flooding

14. Turbidity Results: Increase temperature Decrease in DO
Clogs gills in some aquatic organisms, smothers aquatic plants making photosynthesis difficult

15. Temperature Definition: Amount of kinetic energy Levels:
Low: cannot be tolerated below 320F
High: only rough fish can tolerate temperatures above 970F

16. Temperature Causes: Loss of shade from removal of vegetation
Thermal Pollution: industry discharge
seasonal temp changes
Results:
Decreased levels of DO
increased bacterial levels
increased algae growth

17. 4. Thermal pollution from human activities
Slide 11. Abiotic Factors-Temperature Water temperature is also influenced by human activity. This is North Anna Power Station, located northwest of Richmond. The cooling water from the reactor that is discharged back into Lake Anna is a few degrees warmer than the surrounding lake water.
Temperature increases from human activities
Photo: Dominion Virginia Power – North Anna Power Station

18. pH Description: How acidic is the water Levels: 07 is acidic
7 is neutral
714 is basic
Surface Freshwater: 6.0 9.0

19. pH Cause: Acid rain minerals in soils Results:
Death of sensitive bio-indicators
Death or damage to plants

20. What is pH? 0-7 water is acidic 7 water is neutral 7-14 water is basic
Slide 20. Abiotic Factors-pH
pH is usually a number on a unitless scale, from 0 – being most acidic and 14 being most basic. A pH of 7 is considered neutral, with equal amounts of hydrogen and hydroxide ions.
0-7 water is acidic
7 water is neutral
7-14 water is basic

21. What is the optimum freshwater pH?
Slide 21. Abiotic Factors-pH
The pH of rain depends on the amount of industrialization in the rainfall area. Air pollution from emissions from industry often produce carbonic, sulfuric and nitric acids which lower the pH.
The water which drains a limestone area high in bicarbonates can raise the pH of the water as high as 8.5.
Aquatic organisms are VERY sensitive to changes in pH.
Rainfall: 5 – 6.5
Most freshwater systems:
Most aquatic organisms: 6.5 – 8.2

22. Dissolved Oxygen Description: Oxygen gas dissolved in water
O2 enters water through photosynthesis and churning water
Levels:
4-5 ppm optimal to support life  

23. Dissolved Oxygen Cause: Increased Temp Decaying plant material Effect:
Less diversity of bio-indicators
fish-kills

24. Nitrates & Phosphates Description: Excess nutrients Level:
Nitrates above 1 ppm
Phosphates above .003 ppm

25. Nitrates & Phosphates Cause: Fertilizer run off Animal waste
Leaking septic systems
Manure pits (hog farms, etc)
Clay soils (phosphates)
Result:
Eutrophication – overgrowth of algae (pond scum)
Low DO

26. 1995 Lagoon break at Cape Fear

27. Nitrates & Phosphates

29. What are bio-indicators and how are they used to determine water quality?

30. Bio-Indicators Description:
Macro-invertebrates living in water that are sensitive to pollution
Healthy Level:
Large numbers and diversity

31. Bio-indicators are living organisms that require specific conditions in order to survive. Their presence in waters, or lack of presence, is an indicator of the health of a water system. They can be used as sentinels of a developing problem

32. What is eutrophication
What is eutrophication? Describe the impact of human activity on eutrophication.

33. Bio-Indicators Cause: Increased levels of pollution Result:
Less diversity of organisms
Fewer organisms

34. EUTROPHICATION FLOW CHART Excess Nutrients  Algal Bloom (pond scum)  darkness below surface  photosynthesis stops  decomposers & other organisms use up oxygen  DEATH (gradual buildup of dying plant matter the pond becomes a meadow)

36. Identify each of the following as point source or nonpoint source pollution:
Runoff

37. Stewardship implies that we are caretakers of our water for future generations. The EPA established the Clean Water Act to ensure oversight and testing of surface waters

38. Label the following ocean regions What variables are used to create these regions?

39. Label the following ocean regions What variables are used to create these regions?
Ocean regions are determined by temperature and light penetration
Intertidal
Neritic
Open ocean
Deep ocean

40. Ocean Region
Properties
Adaptations of species that live there
Intertidal
Neritic
Open Ocean
Deep Ocean

41. 1. Intertidal Shallowest area Between the low and high tide lines
Changing environment

42. Each tiny barnacle is enclosed in grayish-colored shells that can completely close. Once they begin life on the rock, they cannot relocate as these shells are attached permanently to their substrate. When dead, the outside shell remains as an empty volcano until it degrades
They have an incredible reproductive style. They are what we call hermaphroditic in biology … that is they are both male and female in the same body. Each animal makes both eggs and sperm, but usually cannot get its sperm to its own eggs. Barnacles have an inflatable penis that is used in mating with a neighbor. This penis can inflate and extend up to 2 inches from the tiny barnacle.
Buckshot Barnacles

43. 2. Neritic Zone Always underwater On continental shelf
Coral reef…diversity & nutrients

44. Phytoplankton =ocean producers
Zooplankton eat phytoplankton
Primary producers are organisms that convert inorganic carbon in carbon dioxide into organic carbon by autotrophs. There are two types of primary producers. They are phytoplankton, or autotrophic producers, and zooplankton, or heterotrophic producers. The neritic zone contains largely diatoms and dinoflagellate species. There are many primary producers in the neritic zone.

45. Sponge with brittle star
Coral

46. Oceanic Zones Open Ocean Surface – 200 meters Sunlight, warm
Less plentiful nutrients

47. Deep Zone - starts at continental slope and extends to 4000 m
Brittle Stars
- starts at continental slope and extends to 4000 m
- little or no sunlight
- cold 4°C
- very high pressure

48. Ogrefish
Deep Sea Angler
Coelacanth

49. How does water move through the ocean?
Water moves through the ocean, driven by currents. Surface currents are caused by waves, deep currents are caused by differences in density.

50. Nutrients move up from the ocean floor through upwelling.
How do climate patterns affect upwelling?

51. How do climate patterns affect upwelling?
Change in climate pattern affects ocean surface temperatures. These alter wind patterns which are responsible of the location and strength of upwelling.

55. Describe the importance of estuaries to the environment.