Students will build plankton models and compete to see which sinks most slowly. Planktonic plants are called phytoplankton. These plants, like plants on land, have the ability to photosynthesize. Using chlorophyll, they capture the energy of the sun to make food, releasing oxygen in the process. Virtually all aquatic life depends upon these microscopic single-celled organisms for food.
Phytoplankton is the main source of food for zooplankton.
Phytoplankton also contributes a significant portion of the oxygen found in the air we breathe. Many zooplankton are able to move up and down in a water column, pursuing food and escaping predators. However, their small size prevents them from moving against the currents. However, if they are too close to the surface, photosynthesis is less efficient. Phytoplankton are found in a fantastic array of shapes, incorporating adaptations which help keep them from sinking.