When you work in IT you pick up what's called 'domain knowledge' - which is to say information about whatever industry you happen to be providing IT for. It's why I can tell you about world rally cars, direct mail order businesses, selling servers, the UK hotel market and all kinds of other odds and ends. Since I joined Greenpeace my domain knowledge has expanded into even weirder areas.

Lately I've been expanding my domain knowledge illegal fishing, that's pirate fishing to you and me. Here's what I've learned so far...

Most ships have an IMO number, that acts as a license plate and unique identifier. But a lot of fishing vessels are too small and don't have to have one. So there is no guaranteed way of working out which ship is which. Vessels engaged in pirate fishing find this very useful.

Ships are allowed to change their name, call sign and flag. When they do so it might be up to a year before the official records reflect this - especially if they're flying a so called 'flag of convenience' that is they're registered with a country where laws and enforcement about ships are lax. Vessels engaged in pirate fishing find this very useful too.

The worlds fisheries are managed by Regional Fisheries Management Organisations - RFMOs - which issue licenses to fish. If you fish in their area without a license you're breaking the law. When a ship does break the law in addition to levying fines or taking other action the RFMO adds their name to a blacklist - in theory preventing them from fishing there again.

It would seem sensible for all RFMO blacklists to be publically available and in one place so ships known to be pirates in one place can be prosecuted or barred from fishing in another. But they're not - this is also good for the pirates.

Beyond the problem of tracking individual vessels comes the problem of tracking who owns them and who buys their fish. Front companies, and other legal fictions abound in this area. It's a classic example of an area where a few simple standards could make a huge difference, but the difficulty lies in getting the governments of the world to agree on a system.

It's also a classic example of the less publicised work Greenpeace does. Chipping away government by government, minister by minister, meeting by meeting to try and bring about these changes. As the world's fisheries head into collapse dealing with this kind of problem becomes more and more important. Will we get our simple solutions to this problem of illegal, unregulated and unauthorised fishing? We hope so.