1. Pollution and Monitoring
In water,
of course!
; ;

2. What is Pollution?
Pollution is the introduction of contaminants into an environment by human activity.
Pollution can take the form of chemical substances
Pollution can also be heat (thermal pollution), noise and light (More on this when we discuss the destruction of atmospheric ozone)

3. Types of Pollution

4. Types of Pollution

5. Types of Pollution

6. Effluent as Pollution
Effluent is an out flowing of water (treated or untreated) into the environment
In this case, effluent is out flowing from sewage or industrial waste
In some countries this can even be raw sewage
Companies may pay fees or taxes in order to discharge in the environment or to a sewer = Effluent Tax

7. Point Source Pollution
The release of pollutants from a single, clearly identifiable site.
Impact is more localized and blame is easily allocated.
Ex?

9. Non-Point Source Pollution
NPS pollution is the release of pollutants from numerous, widely dispersed origins
Because it is hard to tell where the pollution is coming from, it is more difficult to fix and take legal action.
Ex?

11. Temperature
Human activities should not change water temperatures beyond natural seasonal fluctuations.
“Good” temperatures are dependent on where the stream is located.
In a warm water stream temperatures should not exceed about 32 degrees C
Cold water streams should not exceed about 20 degrees C
Often summer heat can cause fish kills in ponds. Why?

12. Aquatic Thermal Pollution
Large inputs of heated water from a single factory or a number of factories using the same lake or slow-moving stream
How else can rivers/streams get overheated?

13. Aquatic pH
Changes in pH values in aquatic locations has an effect on the organisms living at that location.
What would change the pH of a body of water?
Since the majority of aquatic life has adapted to living in certain pH levels, large changes may cause these organisms to die.

14. Aquatic pH Aquatic bacteria can live in a pH level between 2 and 13
Plants between 6 and 13
Carp, catfish, bass, bluegill, snails, clams, mussels and trout can be found in pH levels between 6 and 9.
How might this affect aquatic health?

15. Monitoring Pollution Can be:
direct measuring = recording the amount of pollutant in environment)
Testing for nitrates and phosphates, amount of organic matter or bacteria, and heavy metal concentrations (ie: mercury or lead)
This can cause instability, and harm to the system and the health of the organisms within it.
or indirect measuring = recording changes in an abiotic or biotic factor which are the results of the pollutants.
Abioitic ex: dissolved oxygen (ie Biochemical Oxygen Demand)
Biotic ex: presence or absence of an indicator species =

16. Dissolved Oxygen
Dissolved oxygen analysis measures the amount of gaseous oxygen (O2) dissolved in an aqueous solution
How does oxygen get into water?

17. Dissolved Oxygen

18. Biochemical Oxygen Demand
Biochemical Oxygen Demand or Biological Oxygen Demand (BOD) is a how fast bacteria use up oxygen in a body of water
Measures the amount of dissolved oxygen needed by aerobic decomposers to break down the organic materials in a given volume of water
So, the more organic pollutant (sewage) present…
This decreases the amount of oxygen available to plants and fish!

19. Biological Oxygen Demand
The BOD Test
BOD measures mass (in milligrams) of dissolved oxygen consumed per liter of water when the sample is incubated at a temperature of 20°C after five days in the dark.
Why in the dark?

20. BOD Values? Most pristine rivers will have a 5-day BOD below 5 mg/L
Moderately polluted rivers may have a BOD value in the range of 5 to 10 mg/L
Municipal sewage that is efficiently treated would have a value of about mg/L.
Untreated sewage varies, but averages around 350 mg/L
Cattle slurry is around 10,000 mg/L
Paper pulp mill is around 25,000 mg/L

21. Indirect Method using Biotic Index
A biotic index is a scale (1-10) that gives a measure of the quality of an ecosystem by the presence and abundance of certain species living in it.
Indicator species = plants or animals that show something about the environment by their presence, absence, abundance or scarcity.
They are early warning signs because they are the most sensitive to change or they are very tolerant of chemicals or low levels of oxygen.
Why are these indirect methods?

22. Using the method
How could you use this method to determine if an area of a river is polluted?
Kick nets for Biotic Index
Water Sample for BOD
BOD and Biotic Indices are usually used together:
What does the Biotic Index show that BOD does not?

23. Collecting Organisms

24. Other Abiotic Factors to Measure in Water
Turbidity
Flow Velocity pH
Temperature

25. Turbidity
Turbidity is the cloudiness or haziness of a fluid caused by individual particles, that are generally invisible to the naked eye
The measurement of turbidity is a key test of water quality
How can Turbidity affect the health of an aquatic ecosystem?

26. LaMotte Turbidity Water
Monitoring Turbidity
LaMotte Turbidity Water
Chemical Test Kit
Using a Secchi Disk to measure the depth of water where photosynthesis can still occur
Turbidity Columns
1 is the control with distilled water and the other has the sample water

27. Flow Velocity The speed of water movement
Normally studied in streams or rivers
Time how long it takes for objects to pass between two poles 5 meters apart at different depths and take an average.
How might this affect the health of an aquatic ecosystem?