Cold, clear streams and rivers hold the most oxygen while warm, still water will hold the least. The various cold-water, cool-water and warm-water species will gravitate to areas where both preferred temperature and sufficient oxygen is present. High fertility lakes can have seriously depleted oxygen levels at greater depths. Algae blooms and decaying matter will also lower oxygen levels.
In winter, ice and snow cover can also cause oxygen depletion as plants can no longer produce oxygen due to lack of light.
More on how all this affects fish movement in the following post.