Leaves high and dry on the beaches (7)
I believe the answer is:
strands
I believe this is a double definition.
'leaves high and dry' is the first definition.
(I've seen this in another clue)
'the beaches' is the second definition.
(I've seen this in another clue)
'on' is the link.
(Other definitions for strands that I've seen before include "Leaves helpless on the sand" , "Filaments" , "Strings or chains" , "Maroons" , "Threads or beaches" .)