The minimum landing size (MLS) is the smallest length at which it is legal to keep or sell a fish. What the MLS is depends on the species of fish. Sizes also vary around the world, as they are legal definitions which are defined by the local regulatory authority. Commercial trawl and seine fisheries can control the size of their catch by adjusting the mesh size of their nets.
European Union - A single set

European Fishery MLS

In European Union member states, there exists a standard set of minimum landing sizes for all major species of finfish and shellfish. These MLS are set under EU Council Regulation 850/98.-References:*...

of minimum landing sizes applies to all EU member states.

Other Links

• PDF File from UK Government detailing EU sizes (in English.)