Live chat with the Operation Iceberg team. Live on 30 Oct at 21:00. Join Chris Packham and Helen Czerski with expert scientist Dr Richard Bates and director Matt Barrett.

This product is not optimised for mobile/tablet.

All comments are pre-moderated which may delay publication. It is not possible to publish all comments; only questions and/or comments of interest and relevance to the programme and its themes will be chosen.

Do not include personal information in your comments (eg email addresses, telephone numbers); comments and questions will not be published if they contain personal information or if they contain material that may offend other users.

The BBC is not responsible for the content of external websites linked from this page.

If you want to find out more, go to our T&Cs site.