Plants on vessels, either on deck or within cabins, are a biosecurity concern as they can carry exotic diseases such as karnal bunt, guava rust and plum pox, and also harbour exotic insects.
Examples of insects on vessels that are a biosecurity concern are Asian gypsy moths, Asian tiger mosquitoes, termites, Old-world screw worm fly, and burnt pine longicorn beetle.
Further information on marine pests is available at the marine pest website.