sea wrack vs Zostera marina

sea wrack and Zostera marina both are nouns.

Word	Noun	Adjective	Verb	Adverb
sea wrack	Yes	No	No	No
Zostera marina	Yes	No	No	No

As nouns, sea wrack and Zostera marina are synonyms defined as:

sea wrack and Zostera marina: submerged marine plant with very long narrow leaves found in abundance along North Atlantic coasts

Other synonyms of sea wrack include eelgrass, grass wrack.

sea wrack (noun)	Zostera marina (noun)
growth of marine vegetation especially of the large forms such as rockweeds and kelp	submerged marine plant with very long narrow leaves found in abundance along North Atlantic coasts
submerged marine plant with very long narrow leaves found in abundance along North Atlantic coasts