How are the individual families going to be able to tell salvage operators “which one” is their loved one, to be brought up? I expect they are not all sitting in neat, orderly rows with visible seat numbers.
Have a robot grab a bit of a body with a familiar face for a DNA test to compare with living relatives, I suppose. Or compare to photographs taken when the person was living. Being doused in salt water of that strength would probably preserve features pretty well, just like well-packed pickles.