Light energy Dissolved gases Birds and man Rivers and ice Wave action Surface mixed layer 20-100m Suspended matter Elements in true solution Plants phytoplankton Animals Deep water Elements in true solution in deep water Buried in sediment Physical Processes _Transport by wind_ _Transport by current_ _Turbulent mixing_ _Sedimentation_ _Transport_ by animals _Volcanic action_ _Diffusion_ Chemical or Biological Processes _Photosynthesis_ _Dissolving_ _Upwelling_ _Decomposition and respiration_ _Sorption_ by sediment surface _Redissolving_ from sediment _Chemical precipitation_ Combined Processes _Sedimentation and decomposition_ by bacteria _Scavenging_ Some recent evidence indicates that the passage of a hurricane across the ocean drives surface water out from the storm center in all directions. This, too, produces upwelling. If radionuclides fall on the Arctic ice pack or on the Greenland or Antarctic ice caps, it may be years before they are released to the sea. In more or less stable conditions at sea, radionuclides may remain trapped above the thermocline (a layer of sharp temperature change usually less than 100 meters below the surface) for a considerable period. Then a severe storm may destroy the thermocline and mix the waters to much greater depths. The process of diffusion in the ocean is not well understood, due both to the difficulty of the measurements that have to be made and to the variety of other factors affecting both vertical and horizontal transport of materials. Here again, however, the existence of radionuclides, introduced artificially at a known time and place, is materially aiding these investigations by making a particular water mass detectable and traceable. [Illustration: _Winds of 100 knots (about 115 mph) whip high waves in the Caribbean Sea east of Guadeloupe Island during a hurricane._] In chemical oceanography, the AEC is concerned with the fact that in some instances our society is introducing elements, ions, and compounds that have not been naturally found in the sea, as well as natural materials in greater concentration than is normal. These may combine with other materials in the sea, changing into new forms or substances, or removing them from solution entirely. Any change in the chemical composition of the ocean is quite likely to have biological effects, some of which may prove detrimental to man. A disturbance of the chemical balance of the sea is thought to be responsible, at least in part, for the periodic, disastrous plankton “blooms” known as “red tides”. Such a sudden, explosive overpopulation of plankton is a natural phenomenon, but one that can be triggered by man-made pollution. When it occurs, plankton multiply so rapidly that the oxygen in the water is depleted and many fish die from suffocation.