ABSTRACT

Monthly survey of dissolved vanadium concentration in Lake Biwa has clearly revealed a seasonal variation hitherto unreported. In the surface layer of the lake, dissolved vanadium concentration started to increase in May, reached a maximum value in late summer, and decreased in fall. By contrast, in the bottom layer (70 m depth), the concentration remained almost constant throughout the year. The increase of dissolved vanadium concentration in the eutrophicated southern basin of the lake was greater than the one in the mesotrophic northern basin.