ROSKILDE FJORD

Barnacle

(Balanus improvisus).

The barnacle, which is a crustacean, is found all over the fjord. It is very hardy and can tolerate both frost and drying out. It attaches itself to all sorts of firm surfaces but is known mainly to boat owners as a troublesome growth on hulls. It is thought to have come from America on ships’ hulls in the 19th century.

Barnacles on a propeller.