News and Press Releases

The bad condition of the Baltic Sea is highlighted in the Eastern Gulf of Finland

The Geological Survey of Finland (GTK) has published the results of the joint Finnish-Russian project ‘Sediment geochemistry and natural and anthropogenic hazards in the marine environment of the Gulf of Finland’ (SAMAGOL). The objective of the research describing the state of the eastern Gulf of Finland has been to determine the geology of the seabed and the effect of human activity on the natural environment of the seabed. The GTK carried out the project in cooperation with the VSEGEI research institute in St Petersburg in 2004–2006. Since information about the quality and structure of the sea bed, especially in the eastern parts of the Gulf of Finland, has been fragmentary and rather limited in quantity, the results of this project will improve the overall picture of the relatively delicate environment in question.

The seasonal depletion of oxygen in the seabed was observed to have started around 50 year ago in the deepest basins and to have expanded in later decades to shallower beds. The concentrations of heavy metals have on average slightly decreased in recent years, but the concentrations of cadmium, in particular, are still significantly high. The bad condition of the Baltic Sea is highlighted in the eastern Gulf of Finland where the sea is shallow and heavily polluted.

The Russian side of the project, together with researchers from the GTK, examined the distribution of ferrous manganese precipitates in the research area, which indicates the concentration of heavy metals. During the project, it was observed that the precipitation fields occurring on the Russian side often extend to the Finnish side. The concentration and distribution of arsenic, cobalt, chromium, copper, volumes of heavy metals have also been studied bathymetrically.

The Russian side produced a sediment map of the seabed based on its old research material, which covers nearly all Russian territorial waters in the entire eastern region of the Gulf of Finland. The map is the first accurate sediment map for the area in question and it will act as support in future projects on the use of the seabed.

The publication, Henry Vallius (ed.), 2007, “Holocene sedimentary environment and sediment geochemistry of Eastern Gulf of Finland, Baltic Sea”, Geological Survey of Finland, Special Paper 45, 70 pages, ISBN 978- 951-690-995-3 and 978-952-217-027-9 (PDF), can be borrowed from GTK's library, and is available in the libraries in Kuopio and Rovaniemi and from the GTK in Espoo for EUR 20 (incl. 8% VAT) by sending an e-mail to julkaisumyynti gtk.fi, and is available online at http://arkisto.gtk.fi/sp/sp45.pdf.

For further information, please contact:
Geologist Henry Vallius, Geological Survey of Finland, PO Box 96, 02151 Espoo, tel. +358 (0)20 550 2573 or +358 (0)40 825 2221, e-mail henry.vallius gtk.fi
Geologist Aarno Kotilainen, Geological Survey of Finland, PO Box 96, 02151 Espoo, tel. +358 (0)20 550 2576 or +358 (0)40 062 4939, e-mail aarno.kotilainen gtk.fi

A sample of the sediment from the seabed showing the change from almost structureless gyttja clay to layered gyttja clay at around a depth of 28 cm. The alternation, i.e. lamination, of dark layers preserved in the surface section (0–28 cm) reflects the periodic oxygen depletion at the seabed that has continued for a long time. Picture: GTK. Download (814 kt) 

The distribution of cadmium in surface sediment (from a depth of 0–1 cm). Concentration mg kg-1 mg kg-1=milligram per kilo). Download (1288 kt) 

 Screened ferrous manganese precipitates. Picture: GTK. Download (982 kt)

Taking of samples from sediment on the seabed in the eastern Gulf of Finland. Picture: GTK. Download (1151 kt)

Sediment sample from the seabed of the eastern Gulf of Finland. Picture: GTK. Download (711 kt)

Environmental sample from the seabed of the eastern Gulf of Finland. Picture: GTK. Download (664 kt)