sea creature vs marine creature

sea creature and marine creature both are nouns.

Word	Noun	Adjective	Verb	Adverb
sea creature	Yes	No	No	No
marine creature	Yes	No	No	No

As nouns, sea creature and marine creature are synonyms defined as:

sea creature and marine creature: any of numerous animals inhabiting the sea including e.g. fishes and molluscs and many mammals

Other synonyms of sea creature include marine animal, sea animal.

sea creature (noun)	marine creature (noun)
any of numerous animals inhabiting the sea including e.g. fishes and molluscs and many mammals	any of numerous animals inhabiting the sea including e.g. fishes and molluscs and many mammals