Zonal discrepancy of iodine in the West Pacific Ocean and its adjacent seas

The species of iodine in the water samples collected from the west Pacific Ocean and its adjacent seas were analysed.Results show that the concentration of total inorganic iodine appears higher in the south than that in the north of the Equator.The iodide concentration is distributed symmetrically on both sides of the Equator in tropic and subtropic zones and it decreases away from the Equator.Around the Antarctic Divergence iodide concentration approaches its minimum in the surface waters.which only accounts for 10% of the total iodine.The dissolved organic iodine concentration keeps constant generally either in horizontal or in vertical.Discussions on the relationships of iodine with chemical, biological and hydrological factors reveal that iodine has a transitional behavior between conservative and biodepleting elements; I/S ratio is of a certain stability on a vast scale, however, it may be largely affected by organism activity in some zones.Besides, evidence shows that iodine is adsorbed by organic particle, in surface water but released as the remineral izatiun of the organic particles occurs near the bottom of euphotic layer, which makes iodine look as if it is depleted by organisms like the nutrients.