Oxygen is the key to life — most organisms cannot survive without it, even those under water. Seasonal weather patterns and the physical properties of water can affect temperature and dissolved oxygen levels throughout the water column. Why is this important? Because the seasonal weather patterns and cycles are directly related to how much life an aquatic environment can support.
For example, during the summer, bottom water (hypolimnion) can be cut off from new supplies of dissolved oxygen from the air until fall. Therefore, the size of the hypolimnion affects the ecology of a lake. By examining and graphing water temperatures and the amount of dissolved oxygen in a water column, students will be able to make a connection between the life a lake can support to the amount of oxygen found in stratified layers of water.
Objectives:
- Describe how properties of water are related to productivity in a lake.
- Describe how dissolved oxygen and temperature levels can influence populations of organisms.
- Graph dissolved oxygen levels and graph water temperatures.
- Analyze water temperature versus depth graphs to answer questions.
- Analyze dissolved oxygen versus depth graphs to answer questions.