The distribution of some heavy metals and arsenic in recent sediments from the eastern Gulf of Finland

The highest concentrations of heavy metals in the eastern Gulf of Finland are found in the Neva estuary as well as in the open sea for some metals such as Cd. Vertical profiles show lower amounts of anthropogenically-derived heavy metals in the surface sediments compared to those immediately below. This can be attributed to improved sewage water treatment in St. Petersburg during the last decade as well as to a decrease in the output of industrial waste in Russia as a result of the economic depression. The water depth of the gulf increases westwards. This enables the metals to migrate westwards under the influence of bottom currents when they are released from the sediments by strong currents as is predicted to happen when the Kotlin dam is operating.