6. Current Status of Organotin Contamination and Imposex in Neogastropods Along Coastal Marine Environments of Southeast Asia and China

Organotin compounds (OTs), in particular tributyltin and triphenyltin, have been contaminating various coastal marine environments around the world since their first application back in the 1920s. These compounds have been proven to adversely affect a wide range of marine organisms from microalgae to marine mammals, and they have a great potential of bioaccumulation via the food web. Some OTs such as triphenyltin can even be biomagnified through marine food chains. In Southeast Asia, OT contamination has been a widespread problem because most countries or regions do not implement local regulations to restrict the use of OT-based antifouling paints on seagoing vessels and fish farming facilities (e.g., open-sea cages), although some of them are members of the International Maritime Organization, which has enforced a global ban of such paints since September 2008. Contamination by OTs was the most severe in coastal waters where intensive shipping or mariculture activities could be found. To rectify the problem and safeguard the marine ecosystem and human health, long-term monitoring of OT contamination and enforcement of more stringent regulations on controlling the use and release of these pollutants in Southeast Asian countries are urgently needed.