This post was transferred from my original blog
Fishing is a big environmental problem for a reason that can be summed up in two words:
I know it sounds silly, but bear with me.
National waters are those within 12 miles of the nearest shore, and belong to the same nation as that nearest shore. Beyond that, out to 200 miles, is the EEZ (Exclusive Economic Zone), which is not national territory (so ships of any flag can travel through EEZ waters even without the consent of the country). In the EEZ, the country can regulate economic exploitation of the resources of the sea - ie fishing and offshore oil.
The problem is:
Nations regulate fishing in their EEZ to preserve fish stocks The fish swim out of the EEZ and get caught by fishermen of a different country
The nation then has to reduce fishing even more Fishermen get pissed off because they can't fish and people from other countries can. Fish stocks still decline. This makes regulating fishing extremely difficult. Even worse is that most fisheries extend outside of EEZs altogether, which means that exploitation can't be restricted - sure, national governments can restrict landings in their ports, but you only need one country not to have limits.
I'm not proposing a solution here, just explaining why fisheries policy is such a nightmare.
The EU can reasonably set policy for the Baltic and Irish Seas (The Russian EEZ in the Baltic is tiny). But it needs to negotiate with Norway for the North Sea and with at least Iceland, Greenland, Canada and the USA for the North Atlantic. And parts of the North Atlantic are completely outside of the EEZs.
So, even if the CFP was fixed instead of being a shambles, it still wouldn't work!
A fishery: the range of a single species of fish, or the combined ranges of several species where they overlap and get caught together (so if one species only covers areas A and B and another covers B and C but anyone fishing in B will catch both and can't just catch one or the other, then A B and C form one fishery).