2. Healthy Rivers Water Chemistry

3. Dissolved Oxygen Why is Dissolved Oxygen (DO) Important? Why is Dissolved Oxygen (DO) Important? Aquatic organisms need oxygen to breathe. Aquatic organisms need oxygen to breathe.

4. What Are Some Physical Factors That Influence DO? Temperature Temperature Oxygen is more soluble in water at lower temperatures. Oxygen is more soluble in water at lower temperatures. Altitude/Atmospheric Pressure Altitude/Atmospheric Pressure The higher the elevation the lower the oxygen solubility. The higher the elevation the lower the oxygen solubility.

5. Physical Influences on DO Mixing The more turbulence in water the more surface area there is to absorb oxygen. The more turbulence in water the more surface area there is to absorb oxygen.

6. Biological Influences On Dissolved Oxygen Photosynthesis by aquatic plants and algae Photosynthesis by aquatic plants and algae Produces O 2 during the day. Produces O 2 during the day. Respiration by aquatic plants and animals Respiration by aquatic plants and animals Consumes DO during the day and night. Consumes DO during the day and night.

7. Biological Influences On Dissolved Oxygen Decomposition of organic materials Decomposition of organic materials Dead algae, shoreline vegetation, wastewater decreases DO. Dead algae, shoreline vegetation, wastewater decreases DO.

8. What do the numbers mean? Measured in parts per million (PPM) Measured in parts per million (PPM) Mosquito larvae can survive in water that has 1 PPM and above Mosquito larvae can survive in water that has 1 PPM and above Salmon eggs and young can survive in 7 and above PPM water Salmon eggs and young can survive in 7 and above PPM water Mayflies/Stoneflies can survive in 4.5 PPM and above water. Mayflies/Stoneflies can survive in 4.5 PPM and above water.

9. Turbidity  What is turbidity?  The amount of suspended soil particles (sediment) or algae present in water.  Why is turbidity a concern?  Blocks light needed for photosynthesis.  Reduces visibility for visual feeders.  Smothers fish and amphibian eggs.  Increases water temp by absorbing more sunlight thus reducing the dissolved oxygen.

10. What Causes Turbidity? Erosion of soil. Erosion of soil. Human disturbance increases erosion of soil and organic matter and nutrient runoff which enhances algal growth Human disturbance increases erosion of soil and organic matter and nutrient runoff which enhances algal growth

11. What Causes Turbidity? Suspended algae can be a major problem in the summer. Suspended algae can be a major problem in the summer. Wind, waves, bottom feeding fish, and mammals walking through a stream can re- suspend settled sediment. Wind, waves, bottom feeding fish, and mammals walking through a stream can re- suspend settled sediment.

12. What doe the numbers mean? Measured in Jackson Turbidity Units Measured in Jackson Turbidity Units 0-10 JTU is excellent water quality rating 0-10 JTU is excellent water quality rating 10.1-40 is good 10.1-40 is good 40.1-150 is fair 40.1-150 is fair Above 150 is poor water quality. Above 150 is poor water quality.

13. What is pH? A measure of how acidic or basic a solution is. A measure of how acidic or basic a solution is.

14. pH Why is pH important? Why is pH important? Aquatic organisms are sensitive to high or low pH, especially less than 6.5 or more than 8.5. Aquatic organisms are sensitive to high or low pH, especially less than 6.5 or more than 8.5. The reproductive portion of the growth cycle is particularly sensitive, so while adults may continue to live, they will not reproduce. The reproductive portion of the growth cycle is particularly sensitive, so while adults may continue to live, they will not reproduce.

15. What Causes pH Changes? Algal blooms may raise pH Algal blooms may raise pH Industrial processes and mining release acids and bases Industrial processes and mining release acids and bases Cars release sulfides and nitrous oxides which react with water to form acid rain. Cars release sulfides and nitrous oxides which react with water to form acid rain.

16. Water Chemistry Questions What effect(s) would a dam have on the water chemistry of a river? Why? What effect(s) would a dam have on the water chemistry of a river? Why?

17. Healthy Rivers In groups of four, come up with five ideas to improve the health of a river. In groups of four, come up with five ideas to improve the health of a river. Include how your suggestions would effect the water chemistry of the river and why they would make the river more healthy. Include how your suggestions would effect the water chemistry of the river and why they would make the river more healthy.