Where else to find fish? (4)
I believe the answer is:
eels
'fish?' is the definition.
(I've seen this before)
'where else' is the wordplay.
'where' is an anagram indicator (I've seen this in other clues).
'else' is an anagram of 'EELS'.
'to find' acts as a link.
(Other definitions for eels that I've seen before include "Snakes found in lees" , "Slender fishes" , "Fish (that may be jellied)" , "eg Conger" , "Long thin fish" .)