marine turtle vs sea turtle

marine turtle and sea turtle both are nouns.

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

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

marine turtle and sea turtle: any of various large turtles with limbs modified into flippers; widely distributed in warm seas

marine turtle (noun)	sea turtle (noun)
any of various large turtles with limbs modified into flippers; widely distributed in warm seas	any of various large turtles with limbs modified into flippers; widely distributed in warm seas