Heavy metal contamination in surface sediments in the Gulf of Finland and comparison with the Gulf of Bothnia.

Concentrations of heavy metals in sediments of the Gulf of Finland and the Gulf of Bothnia were studied during 1991-1993. Most of the concentrations reported are for the surface sediments, with background concentrations from deeper downcore included for comparison. The metals studied were mercury, lead, cadmium, zinc, copper, iron, lithium, vanadium, titanium, arsenic, chromium, nickel, manganese and aluminium. The new values for the Gulf of Finland are compared with concentrations for the Gulf of Bothnia. Explanations for the differences in values are suggested and distribution patterns are described. Concentrations of all elements are clearly higher in the easternmost part of the Gulf of Finland and throughout the Gulf the values of total organic carbon, aluminium, chromium, manganese and cadmium are higher in the surface sediments than in the Gulf of Bothnia.