Marine protected areas are becoming an increasingly prevalent management tool for the conservation of marine habitat and the use of marine resources. While there has been much research into the biological benefits of this management tool, economic research has not kept in step with the growing policy interest. This study provides an ex post assessment of the efficacy of the Moreton Bay Marine Park to determine if the expected biological benefits of marine protected areas translate to increased economic rent for the commercial fishers of the bay prawn industry in Moreton Bay. Using the change in standardised log catches as an index of abundance of the bay prawn stock, it was found that abundance has decreased by approximately 4.8% from the declaration of the marine park in 1993 until 2009. The economic rent accruing to the commercial fishers has also decreased over the same period when using industry profit as a proxy for the economic rent. This decrease has been driven by a decrease in catches, a decrease in the price received for prawns and an increase in the fuel price.
A number of factors were identified as to why the Moreton Bay Marine Park has not had a positive effect on catches and the economic rent. These include the absence of spillover effects from protected areas to unprotected areas within the marine park, inadequate protection offered by the marine park, the need for habitat recovery and the large time period necessary for the realisation of benefits. Given these factors, the no-take areas in the Moreton Bay Marine Park may be best managed on a rotational basis where the majority of the protected areas encompass the marine habitats that support crucial life stages in the development of the bay prawn.