Under customary international law open access is allowed in disputed ocean space, and economic theory suggests that under open access resources will be over-exploited with resource rent dissipation. In the case of fisheries there is ample evidence for this, Myers and Worm (2003), for example, reporting that industrial fishing has reduced fish stocks by as much as 90 percent of their levels of fifty years earlier. There is therefore an urgent need for improved fisheries management, and given that the international community has largely rejected oceans management under the common heritage of mankind doctrine, a necessary step is to agree ocean enclosures.