By observing the respiration rate of a goldfish, students explore the relationship between water temperature and dissolved oxygen. Using, first room temperature water, then chilled water, students observe the difference in respiration rates and learn about the value of biological indicators.

.

1. By understanding and identifying sensitive plant or animal populations, humans can use them as biological indicators of ecosystem health.

2. Limiting factors are variables in a system which regulate or restrict further expansion of that system.

3. Temperature directly influences the amount of dissolved oxygen water can hold.