1. Methods of Monitoring Pollution

2. Direct Performed by monitoring the level of the pollutant itself Performed by monitoring the level of the pollutant itself Nitrates in a lake Nitrates in a lake Temperature in a stream Temperature in a stream

3. Direct measurements Measuring temperature in several locations along the length of a river or at different times of the year Measuring temperature in several locations along the length of a river or at different times of the year Take a baseline measurement and then monitor systematically to determine changes Take a baseline measurement and then monitor systematically to determine changes Measuring nitrate levels/ammonia levels/ chloride levels as an indication of nutrient overload Measuring nitrate levels/ammonia levels/ chloride levels as an indication of nutrient overload Measuring TSS or TDS as an indication of material entering the lake or stream Measuring TSS or TDS as an indication of material entering the lake or stream

4. Indirect Monitor the effects of the pollutants on other factors Monitor the effects of the pollutants on other factors Dissolved oxygen Dissolved oxygen BOD BOD Presence or absence of indicator species Presence or absence of indicator species

5. BOD The measure of the amount of dissolved oxygen that is used by aerobic bacteria to break down the organic matter in a specific volume of water. The measure of the amount of dissolved oxygen that is used by aerobic bacteria to break down the organic matter in a specific volume of water. The greater the organic matter (sewage, agricultural run-off, fertilizer, etc.) the higher the BOD The greater the organic matter (sewage, agricultural run-off, fertilizer, etc.) the higher the BOD

6. More BOD If DO equals or exceeds the BOD, the system is considered healthy If DO equals or exceeds the BOD, the system is considered healthy If DO level is less than BOD, it is possible that there is not enough oxygen to sustain larger organisms like fish. If DO level is less than BOD, it is possible that there is not enough oxygen to sustain larger organisms like fish. The process of accumulating large amount of organic matter is called eutrophication The process of accumulating large amount of organic matter is called eutrophication

7. Measuring BOD Measure DO on day 1 Measure DO on day 1 again on Day 5 again on Day 5 samples should be kept at 20 o C in the dark during that time samples should be kept at 20 o C in the dark during that time

8. Factors Controlling BOD and DO A major source of DO comes from the atmosphere A major source of DO comes from the atmosphere Moving water is able to dissolve more oxygen Moving water is able to dissolve more oxygen Temperature is a major factor Temperature is a major factor BOD is affected by respiration or lack there of by microorganisms and by increase in organic matter, waste and sewage BOD is affected by respiration or lack there of by microorganisms and by increase in organic matter, waste and sewage

9. Biotic index Indirect measurement involves monitoring and measurement of organisms in the ecosystem Indirect measurement involves monitoring and measurement of organisms in the ecosystem Indicator or index species Indicator or index species Species by their abundance or absence indicate the level of pollution in an ecosystem Species by their abundance or absence indicate the level of pollution in an ecosystem The diversity of species can indicate the quality and overall health of the system The diversity of species can indicate the quality and overall health of the system

10. Important indicators Fish Fish Bottom fauna Bottom fauna Algae Algae Bacteria Bacteria Comparing the relative abundance of stoneflies, mayflies, and caddisflies to midge and sludgeworms Comparing the relative abundance of stoneflies, mayflies, and caddisflies to midge and sludgeworms Comparison of diatoms to blue-green algae Comparison of diatoms to blue-green algae Measuring coliform levels can indicate the presence of sewage dumping in the ecosystem Measuring coliform levels can indicate the presence of sewage dumping in the ecosystem Overall diversity of the system is the best indicator - presence is better than absence Overall diversity of the system is the best indicator - presence is better than absence