Fisheries rules and control systems are agreed on at EU level, but implemented by the member states through their national authorities and inspectors.

To encourage closer collaboration and exchange of best practice, the European Fisheries Control Agency (EFCA) organises joint control campaigns, where inspectors from different EU countries join forces.
The Commission has its own inspectors, who can visit national authorities at any time to check they are implementing EU rules correctly. It is not their role to inspect individual fishers' operations, however.
When the Commission finds that national authorities are not enforcing fisheries rules properly:

• it first tries to resolve issues through consultation
• in certain circumstances it may temporarily withhold funds from the European Fisheries Fund or close a fishery until the issue is resolved
• any overshoot of quotas is deducted from future quotas
• and when the member state has not taken adequate action, the Commission can take the member state concerned to the EU Court of Justice.