Radionuclide tracers of contaminant fate in the ne atlantic

摘要

Radionuclide tracer studies at the North East Atlantic BBL have delivered import- ant information on parameters required for the modelling of contaminant fate in this area. The residence times of contaminants in the zone of bioavailability are extended due to bioturbation by either advective or biodiffusive mixing, extending up to 20 cm depth in the sediment . Fluxes of material to a site vary because of the influence of bottom currents, so that contaminants may not be evenly distributed over the sea floor but concentrated in specific areas. The presence of the artificial radionuclides ~137Cs and ~241Am proves that anthropogenic contaminants are capable of reaching open ocena sediments within a matter of decades.