Publication Abstract

The occurrence, fate and effects of selected antifouling paint booster biocides in UK docks, harbours and marinas

The occurrence, fate and effects of selected antifouling paint booster biocides in UK docks, harbours and marinas

Kevin V Thomas, John Aldridge, Robert Dyer, Martin Hilton , Mathew McHugh , Jacquie Reed , William Reynolds, and Laura Tolhurst

The International Maritime Organisation (IMO) ban on tributyltin (TBT) as an antifouling paint biocide has raised the profile of the environmental acceptability of alternative organic booster biocides. In this keynote paper we consider work conducted in the UK to establish the occurrence, fate and effects of selected antifouling paint booster biocides in docks, harbours and marinas. Of the eight booster biocides used in the UK, Irgarol 1051 and diuron have been regularly detected in coastal surface water and sediment samples. None of the other biocides targeted have been detected. Laboratory degradation studies showed that Irgarol 1051 and diuron are very stable, whilst other biocides, such as Sea-Nine 211, zinc pyrithione and dichlofluanid rapidly degrade under both aerobic and anaerobic conditions. The affinity of biocides to partition between water and sediment was shown to be an important factor when considering the fate of biocides associated with dredged material. Sea-Nine 211 has the greatest affinity for sediments, however rapidly degrades, and whilst less Irgarol 1051 partitions onto sediment, it has a higher persistence. Contamination of sediments with antifouling biocides incorporated within paint particles significantly increases their persistence no matter of their affinity to sediments. The toxicity of biocides to primary producers show that low ng l^-1 concentrations of certain biocides can pose a risk to certain micro- and macroalgae species. Irgarol 1051 was also showed to bioaccumulate in higher marine plants and algae, although Irgarol 1051 exposed to plants in the form of paint particles was not as bioavailable as free dissolved Irgarol 1051. Modelling the input of the more stable biocides, diuron and Irgarol 1051, following the disposal of dredged material showed that very little diuron enters the sea via this pathway since it has a low affinity for sediments. Due to Irgarol 1051’s higher affinity for sediment, the disposal of dredge material can potentially contribute to 50% of the Irgarol 1051 that enters the sea. The data reported within this paper will be used to assess the overall impact of antifouling paint booster biocides in dredged material.

Reference:

K.V. Thomas, J. Aldridge, R. Dyer, M. Hilton , M. McHugh , J. Reed , W. Reynolds, and L. Tolhurst. 2004. The occurrence, fate and effects of selected antifouling paint booster biocides in UK docks, harbours and marinas. Proceedings of In-Safe 2004

Kevin V Thomas*, John Aldridge*, Robert Dyer*, Martin Hilton , Mathew McHugh , Jacquie Reed , William Reynolds*, and Laura Tolhurst *

Proceedings of In-Safe 2004