1. pH TURBIDITY Water Quality Factors TEMPERATURE DISSOLVED OXYGEN (DO)
PHOSPHATES
BIO-
INDICATORS pH
NITROGEN

2. TEMPERATURE EFFECTS: changes rate of photosynthesis
changes rate of respiration
changes DO in water
cold water holds more DO
hot water holds less DO
changes sensitivity of organisms to toxic
waste, parasites, disease.

3. TEMPERATURE Thermal pollution = adding warm water to cold water.
CAUSES OF THERMAL POLLUTION:
Industry (nuclear power plants, paper mills)
Urban Development (storm water runoff, construction, soil erosion)

4. DISSOLVED OXYGEN (DO) ORANGE = Oxygen MICKEY MOUSE = Water
Less Oxygen =
Less fish
Fish need
Oxygen

5. DISSOLVED OXYGEN (DO) TO INCREASE DO: Much of DO comes from atmosphere
Some of DO comes from photosynthesis
TO DECREASE DO:
Add pollution
Add organic waste

6. ORGANIC WASTE = LOW DO Organic waste = parts of once living things
EXAMPLES OF ORGANIC WASTE:
Sewage
Farm runoff
Discharge from food processing plants

7. HOW RAW SEWAGE LOWERS DO
RAW SEWAGE GOES INTO WATER:
Decomposers chow down
Decomposers take up oxygen
Decomposers reproduce, taking up more oxygen
No more oxygen for other animals
Nothing left but decomposer & sewage-filled water.

8. HEALTHY POND

9. RAW SEWAGE IS DUMPED

10. UNHEALTHY POND

11. pH pH = measure of concentration of hydrogen ions in a substance
Tells whether substance is:
ACID
BASE
NEUTRAL

12. pH Measured on scale from 0 to 14 0 = highly acidic (HCl)
7 = neutral (pure water)
14 = highly basic (bleach)
Seawater pH ranges from 7.5 – 8.5
Average pH of ocean water = 7.8
pH of natural water = 6.5 – 8.5
Optimal range for life = 6.5 – 8.2

13. pH
US Northeastern rain pH = 4.3
Rain elsewhere in US pH = 5.0 – 5.6

14. pH

16. pH SOURCES OF LOW pH IN WATER:
Acid rain is cause of acid in thousands of lakes
Burning fossil fuels has increased acid rain
EFFECTS OF LOW pH IN WATER:
Low pH directly kills fish
pH < 5, most fish eggs die

17. NITROGEN Living organisms need nitrogen to make proteins
Nitrates (NO3) & Nitrites (NO2) are compounds made of nitrogen & oxygen
Some nitrogen in water is good
The wrong amount is bad

18. NITROGEN SOURCES OF NITROGEN IN WATER: Human & animal waste fertilizer
EFFECTS OF TOO MUCH NITROGEN:
Lowers dissolved oxygen (DO).

19. NITROGEN – EUTROPHICATION
Q: How does Nitrogen reduce the amount of DO?
A: Eutrophication
Nitrogen feeds algae (green stuff)
Algae grows & grows
Algae blocks sunlight
Underwater plants die
Algae die and decompose
The decomposition takes up oxygen
No DO for organisms, so they die

20. NITROGEN
OUR HAPPY POND IS
NOW “DEAD”

21. EUTROPHICATION

22. NITRATES

23. PHOSPHATES Phosphorus is an element like hydrogen or oxygen
Phosphorus combines with other things to make phosphates
Essential for living things
Usually present in very small amounts
Too much is bad

24. PHOSPHATES SOURCES OF PHOSPHATES IN WATER: Storm sewer runoff
Soil erosion
Fertilizer
Forest fires
Volcanic eruptions

25. PHOSPHATES

26. PHOSPHATES EFFECTS OF PHOSPHATES:
Eutrophication (same as with nitrates)

27. PHOSPHATES
OUR HAPPY POND IS
NOW “DEAD”

28. EUTROPHICATION

29. PHOSPHATES

30. TURBIDITY Measures clearness of water Murky water = greater turbidity
Caused by solids blocking sunlight
Measured using a Secchi disk or turbidity meter

31. TURBIDITY

32. TURBIDITY SOURCES: Human dumping Construction Soil erosion
Nitrate pollution
Phosphate pollution
HUMAN DUMPING:
Clay
Silt
Industrial waste
Raw sewage

33. TURBIDITY EFFECTS: Clogs fish gills Smothers eggs
Makes water unlivable

34. BIO-INDICATORS
Bio-indicators = organisms that help determine health of water.
Presence or absence tells something about the water.
Not always an accurate way to measure water quality.
Accurate in telling environmental stress

35. BIO-INDICATORS HOW HUMANS AFFECT BIO-INDICATORS: Over-fishing
Industrial pollution
Poor farming practices
Adding foreign species

36. BIO-INDICATORS

37. BIO-INDICATORS