Fouling is primarily combated by the use of antifouling
coatings which are applied to the surfaces of boats or other
marine structures. These coatings rely almost exclusively on
heavy metals particularly copper and tin based compounds
for their active ingredients. These compounds leach into the
water from the coating, killing fouling organisms. Unfortunately,
these compounds also kill non-target organisms in
the environment at large, and the general environmental effects
of these compounds are of worldwide concern (Dalley, 1989).
Tin based coatings are particularly toxic, and such coatings are
now partially (restricted to vessels >25 m in length in Europe
and parts of the USA) or totally banned (Japan) in the world’s
waterways. It is generally accepted that the use of tin (specifically
tributyl tin) based coatings will be completely banned in
most countries within the next 5–10 years