Quota hopping occurs when owners from one country buy ships and obtains a fishing license in another country and fishes against the latter's international quota.
http://lib.s.kaiyodai.ac.jp/library/kiyou/ron3902.pdf
Quotas implemented in Europe are subjected to quota hopping. A common example is a fishing company in Spain that registers its fleet in the UK and fishes under the UK flag, using the UK's quotas. Britain tried to pass a law limiting the number of international fleets registered to 25%, but the EU declared that the law conflicted with the people's right to establishment
Pros: incentive to fish less, money given not to fish
--> but subsidy money is used to expand fishing industry
As a result, the world fleet size is 250% larger than needed to fish sustainably
cost 10-15 billion a year, which is 25% of the 56 billion in total fish industry.