Abstract Concentrations of butyltin compounds (BTs) were determined in harbour porpoise (Phocoena pho- coena) collected from the Turkish coastal waters of the Black Sea. Total butyltin compounds (∑ BTs) in the liver were in the range of 89–219 ng/g on a wet weight basis. The dibutyltin (DBT) residues were higher than those of tributyltin (TBT), suggesting the degradation of TBT to DBT in the liver and the metabolic capacity comparable to other marine mammals. Any sex difference and age-de- pendent accumulation of BTs residues were not found in harbour porpoises, but residue levels increased until ma- turity and then remained constant. When compared with other marine mammals, the present results indicate that the Black Sea is also contaminated with butyltin com- pounds, but to a lesser degree than coastal waters of de- veloped nations. The biomagnification factor in harbour porpoises was 0.8, which was comparable with pinnipeds and lower than cetaceans. Introduction The wide application of organotin compounds such as tributlytin (TBT) in industry and agriculture has been the subject of concern over the past few decades. These chemicals have extensively been used as antifouling paints for vessels and fishing nets and also as herbicides, disinfectants, biocides for cooling systems and stabilizers for PVC plastics. With this use, considerable amounts of organotin compounds have entered the marine environ- ment and caused toxic effects to aquatic organisms [1]. These compounds are hazardous to a wide range of aquatic organisms as evidenced by the thickening of shell and failure of spat in oysters [2], impotence of neogastropods and gastropods [3–6], reduction of dogwhelk populations [7, 8], retardation of growth in mussels [9] and immuno- logical dysfunction in fish [10]. Despite the large amount of toxicological and residue data of organotin compounds in aquatic organisms, the monitoring studies of marine mammals have been started only recently. As the first report, butyltin compounds (BTs) were detected in various tissues of cetaceans from the western North Pacific, Bay of Bengal and Japanese coastal waters and found in significant concentrations [11, 12]. Since these findings, BTs were determined in other marine mammals, such as bottlenose dolphins from Ital- ian coastal waters [13] and USA coastal waters [14], Risso’s dolphins [15], Stellar sea lions [16] from Japan and Ganges River dolphins from India [17]. However, the BTs in higher trophic mammals from various parts of the world, especially Middle East countries, have not been sufficiently studied yet. To understand the present status of contamination by BTs in the Black Sea aquatic ecosystem, an effort has been made in this study to determine TBT and its deriva- tives (DBT: dibutyltin and MBT: monobutyltin) in har- bour porpoise (Phocoena phocoena) and its diet. To our knowledge, no information is available on the accumula- tion of organotin compounds in any animal from the Black Sea. Harbour porpoise is a coastal species and in Bathini Madhusree · Shinsuke Tanabe · Ayaka Amaha Öztürk · Ryo Tatsukawa · Nobuyuki Miyazaki · Emin Özdamar · Orhan Aral · Osman Samsun · Bayram Öztürk Contamination by butyltin compounds in harbour porpoise (Phocoena phocoena) from the Black Sea Fresenius J Anal Chem (1997) 359 : 244–248 © Springer-Verlag 1997 Received: 23 December 1996 / Revised: 15 April 1997 / Accepted: 16 April 1997 ORIGINAL PAPER Dedicated to Professor Dr. Karlheinz Ballschmiter on the occasion of his 60th birthday B. Madhusree · S. Tanabe () · R. Tatsukawa Department of Environment Conservation, Ehime University, Tarumi 3-5-7, Matsuyama 790, Japan A. A. Öztürk Science and Technology Institute, Istanbul University, Ordu Cad, No. 200, Laleli, Istanbul, Turkey N. Miyazaki Otsuchi Marine Research Center, Ocean Research Institute, The University of Tokyo, Akahama, Otsuchi-cho, Iwate 028-11, Japan E. Özdamar Technical Cooperation Division, JICA Turkey Office, Ugur Mumcu Cad. 88/16, Gazi Osman Pasa, 06700, Ankara, Turkey O. Aral · O. Samsun Sinop Faculty of Fisheries, Ondokuz Mayis University, Sinop 57000, Turkey B. Öztürk Faculty of Fisheries, Istanbul University, Ordu Cad, No. 200, Laleli, Istanbul, Turkey