Is he bred for transport by more remote group at sea? (5,8)
I believe the answer is:
outer hebrides
'group at sea?' is the definition.
(group of islands)
'is he bred for transport by more remote' is the wordplay.
'for transport' indicates an anagram (I've seen 'for transporting' mean this (the letters are transported around)).
'by' means one lot of letters go next to another.
'more remote' becomes 'outer' (further out).
'is'+'he'+'bred'='ishebred'
'ishebred' anagrammed gives 'hebrides'.
'hebrides' put after 'outer' is 'OUTER HEBRIDES'.
(Other definitions for outer hebrides that I've seen before include "remote Scottish area" , "Lewis and Harris location" , "The Western Isles" , "Island group containing Lewis and Harris" , "Scots isles" .)