Stone with barnacles

Stone with barnacles, collected by Charles Lim Yi Yong, Singapore, 2017.
Courtesy of Johann Jacobs Museum

This stone comes from Singapore, founded as a colony by the English, and densely populated with barnacles.
Let´s not forget that this barnacle once guided Charles Darwin in writing his theory of evolution. But the crustacean is also remarkable for another reason – it resolved the struggle between the English and the French for global naval supremacy.
The barnacle produces a type of cement that allows it to attach to rocks, buoys and ship hulls. Once cemented, you can’t get rid of the creature.
Any ship whose hull is populated by the shells, not only gets heavier, but also suffers increased water resistance. This in turn slows the ship down. This was the fate of the French fleet – but not the English one. The inventive English discovered that copper fittings, which released poisonous copper oxide, repelled the barnacles.