addition of trace elements or nutrients to the upper layers of the ocean for the purpose of stimulating phytoplankton activity. (3) Pelagic waters The term pelagic waters means the part of the open sea or ocean other than coastal waters. (4) Ocean iron fertilization The term ocean iron fertilization means introduction of low concentrations of iron to high nutrient, low chlorophyll regions of the ocean surface to stimulate phytoplankton production. (5) Marine cdr techniques In addition to ocean iron fertilization, other marine CDR techniques include, but are not limited to, ocean alkalinity enhancement, electrochemical approaches, and kelp and seaweed cultivation.