In order to better understand policies that are currently being used the European Union has a highly regulated system for all of their overlapping waters.
The European seas were already fished by many different countries before fishery management became a national priority. As a result there was a need to have a cohesive management plan beyond the EEZ divisions. Regions that were determined based on stocks and country lines which are shown below.
These zones are then regulated for who can fish and how each area is managed scientifically. Much of this management is technical regulations of how fishing is done. This includes minimum mesh sizes for nets, closed areas for avoid spawning grounds and seasons, minimum landing sizes, and limits on by-catches as a percentage of total catch. Furthermore there are incentives provided to have fishing gear that reduces by-catch.
A main policy of EU fishery management are total allowable catches. These limits are described below based on the scientific evidence of how overfished a region is found be be. It gives the category of how the stock is doing, the level that the catch will be set at and an example of a european stock that is in each category. This helps give a sense of how the science and policy converge.
However, even with these policies, overfishing capacity is still a huge problem. The estimated statistic is that the EU has spent over 2.73 billion since 1994 to try to reduce their fishing fleet. Even with these efforts the fishing capacity has been increasing each year in small increments. This is one of the reasons that the EU is looking to revise their policies for management.
Sources: http://ec.europa.eu/fisheries/cfp/index_en.htm
