Vertical Transport of Chlorinated Hydrocarbons by Sedimentation of Particulate Matter in Kiel Bight

Particulate matter settling out of the water column was collected continuously over a two-year period by means of multisample sediment traps in the coastal waters of the Western Baltic Sea.The content of PCBs and organochlorine pesticides of this matter was determined and compared with its dry weight, and with its organic carbon, nitrogen, and plant pigment content.The pesticide content of this material was highly variable and a marked decline in absolute concentrations was present from 1975-1977; in most samples from 1977, pesticide content was below detection limit.For PCBs, a distinct annual cycle was observed which was inversely related to the rates of sedimentation of seston; highest absolute values for PCBs in each year were recorded during the summer.The input rates of PCBs to the sediments ranged between 112.103 and 24.103 ng m-2y-'.