Fish died after net unfortunately snarled (9)
I believe the answer is:
entangled
'snarled' is the definition.
('entangle' can be a synonym of 'snarl')
'fish died after net unfortunately' is the wordplay.
'fish' becomes 'angle' (angle can mean to fish).
'died' becomes 'd' (abbreviation next to the year of someone's death).
'after' means one lot of letters go next to another.
'unfortunately' indicates anagramming the letters (a bad or unfortunate spelling).
'net' with letters rearranged gives 'ent'.
'angle'+'d'='angled'
'angled' put after 'ent' is 'ENTANGLED'.
(Other definitions for entangled that I've seen before include "Involved in complications" , "caught" , "Confusedly twisted" , "Intertwined; entrapped" , "snarled up" .)