The impacts of wastes and other matter in the marine environment from mining operations is at the core of a working group from the Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP) which is meeting at IMO Headquarters in London (20-22 September). This is the group's first formal meeting and it aims to provide independent advice on what environmental impacts could arise from the marine disposal of mine tailings around the world both from land based and marine minerals mining. A report is being prepared by the group which will inform the discussions taking place in the context of the London Convention and Protocol, the treaties which regulate the dumping of waste at sea. (LC/LP). The event is co-sponsored by IMO and UN Environment and the meeting is being chaired by Dr Tracy Shimmield.