Aquatic Plants & Dissolved Oxygen

Aquatic plants release dissolved oxygen into the water.

Plants require carbon dioxide to breathe. Unlike humans, plants breathe in carbon dioxide and "exhale" oxygen. In the case of aquatic plants, this oxygen is dissolved in the water. This dissolved oxygen is necessary for other forms of aquatic life, such as fish, to breathe.

Types

Different species of aquatic plants introduce different levels of dissolved oxygen into the ecosystem. According to James Cook University, completely submerged plants introduce the most oxygen into the water.

Significance

Some aquatic plants "choke" the ecosystem. One example of this type of plant is floating masses of weeds. Because they grows on the surface of the water, they can block all sunlight from other aquatic plants that are completely submerged. This prevents the aquatic plants below the water surface from completing their photosynthesis cycle, reducing the amount of dissolved oxygen in the water.

Methods

During cloudy days or days when the sunlight is not present, submerged plants actually consume oxygen from the water rather than exhale it. However, they still put about five times more oxygen back into the water than they take out of it.

References

• James Cook University: How Do Aquatic Plants Influence Dissolved Oxygen?
• Pond Professor Plants: Aquatic Plants How to Choose Water Garden Pond Plants

Resources

• Jacksonville Electric Authority: Watching Plants Breathe