Trawling need (3)
I believe the answer is:
net
'trawling need' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for net that I've seen before include "Ultimate" , "It turns in every direction" , "Final profit when all overheads have been deducted" , "Mesh; after tax" , "After expenses" .)