Classification:
Vertebrates
Invertebrates
Herbs
Trees & Shrubs

Data Collection:
Creek Bottom
Dissolved Oxygen
Creek Depth
Creek Clean Up
Invert Sampling
Nitrates
pH
Microorganisms
Phosphates
Vert Sampling
Temp & Humidity
Turbidity

With the exception of a few anaerobic bacteria, all life forms are dependent upon a source of oxygen gas. Most aquatic organisms aquire their oxygen dissolved in water. The level of dissolved oxygen in the water can be an excellent indicator of the primary productivity of an aquatic habitat.

Lower water tempertures, larger amounts of turbulence, shallower water, and increased photosynthetic activity by plants all contribute to an increase in DO levels. Higher temperatures, slower moving or deeper water, and increased rates of decomposition all contribute to lower DO levels. High dissolved oxygen levels supports greater diversity of organisms in aquatic systems.

We use LaMotte's snap off DO viles. They are very easy to use and provide accurate enough readings for establishing a baseline for comparison purposes. The kit runs approximately $38 for 50 tests.

Students testing for DO levels also record the water temperature and rate of flow. In those circumstances whendeep pools are studied, the depth at which the sample is taken would also be recorded.

In the table below are some of the DO measurements taken this year as well as what 100% saturation of DO would be at the given temperature.