To protect against introduced species, some states have laws preventing ocean-going

B. Many are transported in ballast water.

Explanation: Ballast water is the water that ships take in order to keep their weight when they discharge materials on ports. As this water is taken without any filter, ships take also a lot of organisms (animals, plants, microorganisms or viruses). This water is then released in other ports liberating all the organisms contained which can affect the equilibrium of the new area reducing local populations or affecting human life by diseases.