Question

When would use marine as an adjective? aquatic?

Answer 1

The example I like to use is the following:

A fish is a marine animal.

Answer 2

Answer:

Marine as an adjective can modify many nouns. One of its most common collocations is the noun life, such as in Overfishing is threatening marine life in the Atlantic Ocean. A different example would be My daughter is interested in marine studies.

Aquatic can also be used to describe something living in water or related to it, such as in the sentence Frogs are usually near aquatic environments.