As reported by the Environment News Service, Australia has become the first country to sign the International Convention for the Control and Management of Ships' Ballast Water and Sediments. The convention was approved by the International Maritime Organization back in early 2004 (link to related ISW posts). Of course, this signing doesn't mean regulations are about to go into effect - Australia now need to apply "due parliamentary scrutiny" to determine whether they should ratify the convention. Plus, the Convention won't be enacted until one year after 30 countries have all ratified it.
Thanks to Bryan N. for sending in a link to this story.