Dr. Cecil Beamish:

Colloquially, the term is used both ways. Ireland has a 200 mile zone. Like any other such zone, Ireland is responsible for control and enforcement in the 200 mile zone but what swims in that zone is managed by European law. That is the same in any other instance. Ireland catches two thirds of its fish in its own 200 mile zone and the remaining one third outside of that zone in the 200 mile zones of other countries. No country has exclusive rights to a 200 mile zone in terms of what swims in the water. That is the way this works.