Vertical distribution and transport of molybdenum in a lake with a seasonally anoxic hypolimnion

Distribution and trends of Mo concentrations in the seasonally anoxic Lake Greifen were investigated over 15 months. Mo in water samples and settling particles was determined by catalytic adsorption polarography and inductively coupled plasma mass spectrometry. Mo concentrations in the epilimnion were usually homogeneous at −0.48 µ g liter −1 . A significant decrease with depth was found during the stratification period. The lowest Mo concentrations (0.31 µ g liter −1 ) were found in the presence of H 2 S near the sediment. A vertical flux of particle‐bound Mo of 1.1–4.6 µ g m −2 d −1 was found. The Mo concentration‐depth profiles result from a combination of different transport mechanisms that are compared by computer model calculations.