Collector of shoreline debris (11)
I believe the answer is:
beachcomber
'collector of shoreline debris' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for beachcomber that I've seen before include "Collector of shoreline debris" , "scavenger" , "Vagrant; rolling wave" , "Flotsam collector - pearl-fishing Pacific island settler" , "Vagrant living by the sea" .)