Over the last few hundred years, most of the world's harbors have been invaded by non-native sea squirts that have clung to ship hulls or to introduced organisms such as oysters and seaweed.
Desde hai algúns centos de anos, a maioría dos portos do mundo foron invadidos por ascidias non nativas que se colgaron dos cascos dos barcos ou viñeron con organismos introducidos como ostras e algas.