They are collecting sea water and seaweed that will be processed to collect salt (burning seaweed, mixing ashes with water to make saturated salt, and boiling the mixture to evaporate the moisture, leaving the salt behind).
(They; are collecting; sea water and seaweed that will be processed) (sea water and seaweed; will be processed; to collect salt) (salt; burning seaweed; )
They sea water and seaweed salt
are collecting will be processed burning seaweed
sea water and seaweed that will be processed
to collect salt