We hear anglers making cracks (8)
I believe the answer is:
fissures
'cracks' is the definition.
(I know this)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for fissures that I've seen before include "Cracks" , "Narrow clefts" , "Long narrow openings" , "Chasms" .)