Aquatic plants and algae live in the water and are autotrophic, which means they can produce their own food. All other living organisms rely on autotrophs for energy and nutrients. Many marine animals also rely on aquatic plants and algae as habitat. All animals also depend on the oxygen produced by autotrophs.

Ocean Literacy Principles

Principle 4: The ocean makes Earth habitable.

Ocean Literacy Fundamental Concept: Most of the oxygen in the atmosphere originally came from the activities of photosynthetic organisms in the ocean. (OLP 4a)

To build an understanding of how the ocean makes Earth habitable, it is important to learn about autotrophic organisms and photosynthesis.

These concepts will be explored in this unit through the following activities and investigations:

Principle 5: The ocean supports a great diversity of life and ecosystems.

Ocean Literacy Fundamental Concept: Ocean life ranges in size from the smallest virus to the largest animal that has lived on Earth, the blue whale. (OLP 5a)

Ocean Literacy Fundamental Concept: Some major groups are found exclusively in the ocean. The diversity of major groups of organisms is much greater in the ocean than on land. (OLP 5c)

Ocean Literacy Fundamental Concept: Ocean biology provides many unique examples of life cycles, adaptations and important relationships among organisms (such as symbiosis, predator-prey dynamics and energy transfer) that do not occur on land. (OLP 5d)

To build an understanding of how the ocean supports a diversity of living organisms and ecosystems, it is important to learn about the biology of autotrophs.

These concepts will be explored in this unit through the following activities and investigations: