With these surface waters, through a series of delicately adjusted, interlocking relationship, the life of all parts of the sea is linked. What happens to a diatom in the upper, sunlit strata of the sea may well determine what happens to a cod lying on a ledge of some rocky canyon a hundred fathoms below, or to a bed of multicolored, gorgeously plumed seaworms carpeting an underlying shoal. or to a prawn creeping over the soft oozes of the sea floor in the balckness of mile-deep water.