Mobility of metal-organic pollutants in the emerging coastal-marine sediment of the Baltic Sea: The case-example of organotin compounds in sediments of the Gulf of Finland

Abstract

Results of organotin and heavy metals pollution study of bottom sediment within three key areas in the Eastern Gulf of Finland (Baltic Sea) in the vicinity of Gogland and Moschny Islands and Vyborg Bay sampled during two seasons of 2017 and 2018 are presented.The studied bottom sediments contain organotin compounds in amounts (∑OTs from 5.7 to 123 ng/g) exceeding the permissible international standards, which can have a toxic effect and lead to pathological changes of aquatic organisms. The tributyltin was the prevail component of organotin compounds in bottom sediments in 2017, which high content (average 6.3 and 30 ng/g for Moschny and Gogland islands respectively) and low degradation coefficient (BDI: 0.1–0.8) indicate a permanent source of pollution. But the 2018 samples show an increase in BDI up to 1.7–3.3 that reveals the degradation of tributyltin over the annual period. But further monitoring of environmental pollution in the study areas is obviously necessary in view of the potential impact of these components on the irreversible change in the environmental situation for the entire Baltic region.