Concentrations of the Antifouling Compound Irgarol 1051 and of Organotins in Water and Sediments of German North and Baltic Sea Marinas SCARLETT BISELLI , KAI BESTER , HEINRICH H  UHNERFUSS * and KARL FENTà  Institute of Organic Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany àSwiss Federal Institute for Environmental Sciences and Technology (EAWAG), Swiss Federal Institut of Technology (ETH), Ueberlandstr. 133, CH-8600 D ubendorf, Switzerland A survey of 2-methylthio-4-tert-butylamino-6-cyclopro- pylamino-s-triazine (Irgarol 1051) and organotins, used as biocides in antifouling paints, was carried out in German marinas of the North and Baltic Sea. Highest levels of the s-triazine herbicide were found in Baltic Sea marinas where water exchange was restricted (water up to 440 ng/l; sed- iment about 220 ng/g dry weight), while in the North Sea marinas with higher water exchange rates lower concen- trations were encountered (water 11±170 ng/l; sediment 3±25 ng/g dry weight). Although the application of the antifouling agent tributyltin (TBT) was banned for small vessels (<25 m) in Germany and other countries in 1989, signi®cant levels of TBT between 570 to 17 000 ng/g dry weight, lower concentrations of triphenyltin (TPT) of up to 3800 ng/g as well as the TBT degradation products dibu- tyltin and monobutyltin occurred in sediment samples of the Baltic Sea marinas. In the North Sea marinas with stronger water exchange the TBT sediment levels ranged from about 80 to 720 ng/g dry weight. This study shows parallel con- tamination patterns of Irgarol and organotins in North and Baltic Sea marinas and the persistence of several organo- tins in these sediments about eight years after the ban. A seasonal dependence of Irgarol 1051 concentrations was found both in the water and sediment samples, with maxima during the periods March±May/July±September, while during the winter period December±January low values were encountered though measurable amounts remained in the sediment. A mean value of the partitioning coecient log K OC =3:3%0:72 was inferred from the water and sediment concentrations determined in seven Baltic Sea marinas. Ó 2000 Elsevier Science Ltd. All rights reserved. Keywords: Irgarol 1051; Organotins; Sediment; North and Baltic Sea. Leaching of biocides such as tributyltin (TBT) and triphenyltin (TPT) from boats and ships coated with antifouling paints resulted in potential toxic concentra- tions of these compounds in coastal waters with high boating activity (Alzieu et al., 1986; Alzieu, 1991; Fent, 1996). As a consequence, legislation in many countries banned the application of TBT in paints to small vessels (<25 m) (European Community, 1989) and alternative products such as the s-triazine herbicide Irgarol 1051, often combined with copper oxides, replaced TBT as an antifouling compound. In November 1998 the Interna- tional Maritime Organization agreed to ban organotin antifouling paints on ships by 2003 (Christen 1999). Since the application of TBT has been restricted, re- duction of environmental contamination was reported in many countries including France, Germany, Swit- zerland, UK and the USA (Fent and Hunn, 1991, 1995; Dowson et al., 1993; Huggett et al., 1992). However, although levels of TBT concentrations in water declined, they are still in the range of chronic toxicity towards most susceptible marine organisms. Sedimentary levels remained at high concentrations, with only a slow de- crease in the last 10 years, which might be due to the low degradability of TBT (Fent and Hunn, 1995; Langston and Pope, 1995). In recent studies, relatively high con- centrations were still observed, and, therefore, sediments remain the major reservoir for organotin compounds which may potentially aect benthic organisms (Fent and Hunn, 1991, 1995; Fent et al., 1991). Several ®eld and laboratory studies have documented that extremely low environmental levels of TBT can exert lethal and sublethal eects on ecologically and economically im- portant species, e.g., imposex (Bryan and Gibbs, 1991; Fiorini et al., 1991) or intersex (Bauer et al., 1997) in several gastropod species, malformed oysters (Crassos- trea gigas) (Alzieu et al., 1989), increased mortality and reduced growth rate in blue mussel (Mytilus edulis) larvae (Beaumont and Budd, 1984) and Marine Pollution Bulletin Vol. 40, No. 3, pp. 233±243, 2000 Ó 2000 Elsevier Science Ltd. All rights reserved Printed in Great Britain 0025-326X/00 $ - see front matter PII: S0025-326X(99)00177-0 *Corresponding author. Tel.: +49-40-42838-4240; fax: +49-40- 42838-2893. 233