Total and organic phosphorus in waters of the Bering Sea, Aleutian Trench and Gulf of Alaska

Total phosphorus was determined on some 170 samples from eleven stations in the Bering Sea, the Aleutian Trench, and the Gulf of Alaska. Samples ranged in depth from the surface to 7000 m. In these samples organic phosphorus, estimated as the difference between total and inorganic phosphorus, bears an inverse relationship to the distribution of inorganic phosphorus. Surface waters, generally low in inorganic phosphorus, contain up to 1·0 μg. at./L organic phosphorus, with a grand average of 0·27 μg. at./L for the upper 200 m. The amount of organic phosphorus present in surface waters reaches values as high as 47 per cent of the total. On the other hand, waters below about 200 m. have little or no measurable amounts of organic phosphorus. In its vertical distribution, total phosphorus varies at the most by a factor of three and is more or less uniform with depth compared to the inorganic phosphorus. Inferences are drawn concerning the nature of organic matter and the state of organic phosphorus in deep waters. The observed distribution of various forms of phosphorus substantiates the theory that the major part of the phosphorus cycle is enacted in the surface layers.