1. DO NOW 1.Get out your calendar 2.Put your Water Filtration Lab in the bin 3.List and explain the steps of water filtration

2. Survey Complete the survey and turn it in to the bin.

3. What is dissolved oxygen? Amount of oxygen measured in water Measured in milligrams per Liter (mg/L) OR parts per million (ppm) mg/L = ppm

4. How does oxygen enter the water? Direct absorption from the atmosphere Photosynthesis

6. How is oxygen in the water used? Plants and animals use oxygen for respiration Aerobic Bacteria use oxygen during decomposition Dissolved oxygen decreases when organic pollutants enter the water because bacteria use the oxygen for decomposition.

7. Think of the fish!

8. How is dissolved oxygen measured? Electronic Meters Chemical Analysis Measured in mg/L or ppm

9. Concentrations of dissolved oxygen for a healthy stream: D.O. ranges from 0 – 18ppm Healthy = 5 – 10 ppm 3 – 4 ppm and fish or other aquatic life are stressed A decrease in D.O. indicates an addition of an organic pollutant

12. Natural factors that affect dissolved oxygen concentrations: 1. Temperature – cold water has _______________ dissolved oxygen. more

13. Natural factors that affect dissolved oxygen concentrations: 2. Flow – faster moving water has _______________ dissolved oxygen. more

14. Natural factors that affect dissolved oxygen concentrations: 3. Aquatic Plants – release oxygen through ________________________________ so plants are the main source of dissolved oxygen in water photosynthesis

15. Natural factors that affect dissolved oxygen concentrations: 4. Suspended Solids – describes stuff dissolved in water, less suspended solids the ___________ dissolved oxygen more

16. Relationship between dissolved oxygen and temperature: Colder temperature = higher dissolved oxygen

17. Factors that affect the temperature of a stream: 1.Time of day (morning vs. evening) 2.Seasons or Time of year 3.Quantity and Velocity of stream flow 4.Human Activities (Thermal Pollution from industry)