Anthropogenic impact and aquatic ecosystem health of Lake Baikal

Projektinformationen

ID Finanzhilfevereinbarung: INTAS-94-0531

Projekt abgeschlossen

Startdatum 1 August 1995

Enddatum 31 Juli 1998

Finanziert unter

• International Association for the promotion of cooperation with scientists from the independent states of the former Soviet Union (INTAS), 1993-

Gesamtkosten € 0,00

EU-Beitrag € 90 000,00

Koordiniert durch

Università degli Studi di Siena
Italy

Exploitable results

Anthropogenic impact and aquatic ecosystem health of Lake Baikal

The objectives of this project was to establish the integrity of Lake Baikal and its ecosystem and to evaluate the levels of persistent contaminants with relevant ecological impact, in order to give some indications for the maintenance of the integrity of the lake. During the project, a large number of samples from a wide range of species in the Lake Baikal and the Selenga River area have been collected and analysed for a range of organic and inorganic pollutants. The main findings of the project may be summarised as follows : There was evidence of marked bioaccumulation of persistent organic pollutants (PCBs, pp'DDT and pp'DDE) in the lake Baikal food chain : phytoplankton - zooplankton - fish (especially sculpins) ) seals. Substantial levels of pp'DDT (up to 25 µg/g wet weight) were detected in seal blubber samples taken during 1997/98. The relatively low levels of its highly persistent metabolite pp'DDE in the same samples (often at lower concentrations than pp'DDT itself) suggest that there has been a recent contamination of the Lake with this neurotoxic insecticide the use of which has been banned in Russia for a number of years. Bird eggs from the Selenga river estuary contained a wide range of toxicants with high levels of PAHs (higher than 8 µg/g dry weight) detected especially in the goose and the lapwing. Birds eggs sometimes contained persistent pollutants (e.g. polychlorinated benzenes) which were not generally detected in the Lake Baikal food chain and which are believed to have been taken up elsewhere during migration. Total mercury pollutions was high in the muscle of predatory fish in lake Baikal ; the results point to the possibility that much of this pollution is due to anthropogenic activities along the Selenga river especially in Mongolia. A high number of pollutants was found in snow samoles suggesting that some pollution may be due to air movements over large distances ; no organophosphates were found in these snow samoles but half of them contained high levels of heavy metals.