Grass around the seaport (7)
I believe the answer is:
esparto
'grass' is the definition.
(type of grass plant)
'around the seaport' is the wordplay.
'around' is an anagram indicator.
'seaport' is an anagram of 'ESPARTO'.
(Other definitions for esparto that I've seen before include "Grass, used for ropes, paper" , "Grass fibre for mat-making" , "Rope-making process" , "Coarse type of grass" , "Source of paper" .)