2. Water Quality Index

3. Announcements n HOURS due Monday! n Still an opening for Science Night

4. Dissolved Oxygen n Most important characteristic. n Source is waves, riffles, and aquatic plants. Used up by the decay of organic wastes. n Effected by temperature of the water. Colder water holds more oxygen. n Low D.O. has largest effect on aquatic life, all parts of the food chain.

8. Fecal Coliform n Measure of animal wastes in the water. n Not pathogenic, but indicate the likelihood of pathogens. n Safety, not ecosystem issue.

9. pH n The measure of acid or base. n Normal range is 6.5-8.5 n rainwater 5.5, types of rocks determine the normal pH. n Most pollution is acid. n Most wildlife is very pH specific. Most insect larva are very sensitive to changes.

10. Biological Oxygen Demand n Measurement of how rich in nutrients (organics) the water is. How much oxygen is consumed by bacteria during 5 days. n Organic sources include paper and food industries and wastewater treatment plants.

12. Temperature n Change in temperature is a stress on ecosystem. n Amount of D.O., rate of photosynthesis, and metabolism of animals are all effected.

14. Total Phosphates n Usually THE limiting factor in aquatic plant growth n Important fertilizer, triggers cultural eutrophication. (artificial ageing) n Source is wastes and fertilizer runoff. n Can cause algae “bloom”, severe ecosystem stress.

18. Nitrates n Part of the nitrogen cycle (Atm nitrogen N 2, ammonia NH 3, nitrites NO 2, Nitrates NO 3.) n Much more common than phosphates. Necessary for protein production. n Major source is sewage (waste and decomposition)

20. Turbidity n How cloudy or clear the water is. Visability, measured in feet. n Measure of the SUSPENDED solids. n High turbidity reduces diversity and photosynthesis. It also increases temperature.

22. Total Solids n The material both dissolved AND suspended in the water. n Dissolved minerals include calcium, iron, sulfur. n High TS hampers organisms. n Low TS can be a limiting factor.