1. Water Quality Indicators Physical Indication of Water Pollution

2. To a great extent, the success or failure of an aquatic ecosystem is determined by water quality

3. Temperature Temperature Dissolved oxygen Dissolved oxygen Total ammonia-nitrogen, NH 3, NO - 2 Total ammonia-nitrogen, NH 3, NO - 2 Alkalinity & HardnessAlkalinity & Hardness pH pH TurbidityTurbidity SalinitySalinity Water Quality Variables

4. How water quality values are expressed as: ParameterValue Dissolved oxygen mg/L or ppm Water temperature Degrees C or F pH Total ammonia nitrogen mg/L or ppm Nitrite Alkalinity/Hardness mg/L or ppm CaC0 3 Salinity g/L or ppt salt

5. Temperature Normal temperature: 22 degrees C Sources: sunlight, thermal pollution Effects: amount of oxygen that can dissolve, photosynthetic rate, metabolic rates change, sensitivity to toxic wastes Normal temperature: 22 degrees C Sources: sunlight, thermal pollution Effects: amount of oxygen that can dissolve, photosynthetic rate, metabolic rates change, sensitivity to toxic wastes Water temperature fluctuates seasonally, resulting in thermal stratification in deeper water. Water temperature fluctuates seasonally, resulting in thermal stratification in deeper water.

6. Dissolved oxygen and water temperature dissolved oxygen and water temperature usually vary over a 24 hour cycle. 6 a.m. midnight 6 p.m. noon 0 15 10 5 Surface dissolved oxygen, mg/L 25 27 29 31 Surface water temperature, °C summer

7. Stratification can cause dissolved oxygen and temperature to vary at different depths in the same pond. Dissolved oxygen and water temperature Epilimnion Thermocline Hypolimnion High temperature High dissolved oxygen Low dissolved oxygen Low temperature In general the minimum DO should be ≥ 60% of saturation or ≥ 5 ppm (mg/L)

8. Turbidity Measures the amount of suspended particles in water Measures the amount of suspended particles in water Too turbid, then what are the effects? Too turbid, then what are the effects? – Temperature rises – Fish may have difficult finding a mate – Clogs fish gills

9. pH = - log [ H + ] 01 2 345 6 78910111213 14 acidalkaline pH pH is a measure of acidity (hydrogen ion concentration) in water or soil. pH is a measure of acidity (hydrogen ion concentration) in water or soil. neutral

10. T otal A mmonia N itrogen Total ammonia nitrogen ( TAN ) is a measure of the unionized-ammonia (NH 3 ) and ammonium levels (NH 4 + ) in the water The ratio of ammonia and ammonium varies in an equilibrium determined by pH and water temperature. Ammonia as a % of total ammonia nitrogen

11. Nitrite/Nitratefeces Bacterialdecomposition NH 4 + +1.5 O 2 + Nitrosomonas NO 2 - + 0.5 O 2 + Nitrobacter NO 3 - nitritenitrate

12. Alkalinity and Hardness Alkalinity buffers against variations in pH.

13. Salinity Fresh water is less than 2 g/L Brackish water is 2 g/L to 34 g/L Sea water is more than 34 g/L NaCl