Left after dam ruined coral island (8)
I believe the answer is:
mallorca
'island' is the definition.
(I know that Mallorca is a island)
'left after dam ruined coral' is the wordplay.
'left' becomes 'l' (common abbreviation).
'after' says to put letters next to each other.
'dam' becomes 'ma' (dam can mean the mother of an animal).
'ruined' is an anagram indicator.
'coral' with letters rearranged gives 'lorca'.
'l' after 'ma' is 'mal'.
'mal'+'lorca'='MALLORCA'
(Other definitions for mallorca that I've seen before include "From Mediterranean island" , "Spanish island" , "part of Spain" .)