Hannesson (Marine Resource Economics 13(3) 1998) takes a critical approach to marine protected areas (MPAs) using simulations of MPAs combined with open access. His results show the conservation effect of an MPA of an appropriate size being the same as that achieved with optimal quota regulation, but with a smaller catch. We expand this analysis by adding a management cost function and increasing the fishing costs to a more realistic level. It is shown that the use of MPAs of certain sizes can be a more advantageous management tool than traditional quotas; hence, the inclusion of management costs modifies some of the findings of Hannesson (1998). We also illustrate how sensitive the results are to the choice of fishing cost values, making the attractiveness of private property versus marine reserves much less clear than proposed by Hannesson (1998).