Iodine in the deep water of the ocean

Abstract

The distribution of iodine in the ocean has been studied to ascertain the source of the iodide in deep water. Iodide in sea water was separated from iodate immediately upon sampling and both forms were determined. The concentration of iodide in the ocean is much smaller than that of iodate. The higher concentrations of iodide, however, were found in the surface water, near the bottom and in the water from some deep layers. The production rate of iodide from iodate in the bottom (or on the bottom) has been estimated from the vertical distribution of iodide in the near-bottom water. This also gave the oxidation rate of iodide in the deep water. The production of iodide in the bottom water plays a fairly important role in the cycle of iodine in the ocean. Another source of iodide is presumed to be present in the deep water by taking into account the oxidation rate of iodide and the balance of iodide in the deep water. This source may be distributed locally and cause the higher concentrations of iodide found in some deep layers. The contribution of these two sources is much larger than the iodine from the decomposition of organic matter in the deep water.