harvesting {TAIL ~ a portion} of {HEAD ~ said algal turf} onto and into which said pollutants have precipitated 
harvesting { TAIL ~ a portion } of { HEAD ~ said algal turf } onto and into which said pollutants have precipitated
OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH