What are the opposite words for macroalga?

Macroalgae, also known as seaweed, are a type of aquatic plant-like organism that grows in the ocean. The word 'macroalga' doesn't have antonyms as it is a specific term used to describe this type of seaweed. However, other words related to macroalgae like microalgae, which are small algae, and phytoplankton, which is microscopic plant life, can be considered antonyms as they are different types of aquatic organisms. Additionally, terrestrial plants, such as trees, shrubs, and grasses, are antonyms to macroalgae as they grow on land instead of in water.