The EU has agreed on common inspection rules to prevent overfishing and make it possible to trace fish "from net to plate", the European Commission says.
The rules include a new point system to punish crews who fish illegally. If they accumulate too many points they will lose their licence.
EU nations police their own fisheries, but they have agreed on common inspection and reporting methods.
The controls are part of a big reform of the EU's Common Fisheries Policy.
Fisheries Commissioner Maria Damanaki said fishing data would be cross-checked electronically across Europe and law-breakers would face equally severe sanctions, whatever their nationality.
Ms Damanaki said: "We can no longer allow even a small minority of fishermen to ignore the rules."
Many EU fish stocks are seriously depleted - hence the drive to overhaul the Common Fisheries Policy (CFP) by 2012.
Critics of the CFP have argued that it is not applied evenly across the EU.
The new controls replace and update old rules that were scattered in different regulations, the Commission says.
The Commission will be empowered to carry out checks on member states' fisheries controls and reduce certain fishing quotas if the EU inspectors find serious infringements.