Source One: This site gives an overview of the importance of oxygen in water. It states that low dissolved oxygen levels can be harmful to aquatic life. Low oxygen in water can even kill fish and other organisms. This website also explains the effects of climate on water. The amount of dissolved oxygen that can be contained in water is dependent on the temperature of water. As the temperature decreases, the density of the water increases. This creates different layers of more dense and less dense water.
Source Two: The Department of Ecology’s site says that oxygen is crucial to the water functioning in it’s area. This site stresses the natural variation in amounts of dissolved oxygen in certain locations. It is normal for levels of dissolved oxygen to vary quite a bit even in the same body of water. This site also states that the summer is the hardest time for fish because the levels of oxygen in the water are lower.