Effects on marine organisms of sediments contaminated with tributyltin with special reference to sub-arctic and arctic conditions The use of antifouling paints based on tributyl tin (TBT) is now restricted in most European countries. However, the prohibition involves only vessels less than 25 m length. As a result many coastal areas and harbours show raised levels of TBT in water and sediment, high enough to cause effects on sensitive organisms. Dredging operations in such areas may increase exposure of organisms to TBT. As the degradation processes are temperature dependent contamination by TBT in arctic or sub-arctic waters may be more serious. The specific objectives of this study, which is performed in co-operation with the University of Iceland (Prof. J. Svavarsson), are to evaluate a/ the effect of temperature on the uptake of TBT by the gastropod Buccinum undatum during exposure to TBT-contaminated sediment and b/ the effects of contaminated sediment on the development of imposex (penis and vas deferens development of females) at different temperatures.The project involves both laboratory experiments and field studies. The project started in late autumn 1995 and results are not yet available. Effects of TBT- and triazine/copper based antifouling paints on the early development of cod Elevated amounts of components from antifouling paints has been found in sediment and in organisms in Icelandic coastal waters. Also imposex in dogwhelks and whelks has been observed. In order to evaluate any impact on the economically important fishery and especially focused on cod, experiments are performed in the laboratory following the early development of the fish from fertilization up to hatching when exposed to antifouling components. No results are yet available. Effects of antifouling agents in the marine environment. Early development in lumpsucker (Cyclopterus lumpus) preliminary studies. The objectives of the study are to reveal the effects of chemicals from antifouling paints on the development of the lumpsucker (Cyclopterus lumpus) - in situ and under laboratory conditions. The study focuses on TBT (tributyltin) and a chemical, Sea-nine, replacing TBT as the major toxic agent. We will evaluate the effects of TBT in the laboratory and under field conditions, but Sea-Nine under laboratory conditions only. Laboratory studies are based on the use of flowthrough conditions with different concentrations, while in the field studies we use cages with eggs and larvae. The eggs of the lumpsucker are allowed to glue to glass slides following fertilization. These are then easily transferred to either laboratory set up or into small cages, which will be set out at different distances from harbours. Also semipermeable membrane devices (SPMD:s) will be used in order to determine the actual water concentrations. The effects of TBT from the harbours is evaluated by measuring imposex in gastropods (Nucella lapillus) at the coastline. The mortality of the eggs and the larvae is determined and different physiological measurements are made in order to detect sublethal effects of the contaminants in question. The project has just started and no results are yet available.