With the exception of the Great Barrier Reef Marine Park, there have been no prosecutions for specific offences within marine protected areas (MPAs) in Australia at the federal level or in Tasmania and New South Wales. However, it cannot be assumed that compliance is responsible for this lack of prosecutions. Rather, in some cases, enforcement officers prosecute offences under more general provisions found in fisheries legislation than under provisions for specific offences created in MPAs. In other cases, there has been a long lag time between the declaration of MPAs and the adoption of comprehensive and effective legislative arrangements creating offences for specific activities within them. Hence, there may be periods during which MPA regimes fail to give adequate legal support to the environmental objectives they seek to achieve, partly because of the need to 'phase out' existing fishing activities. Additionally, they may fail to prohibit inappropriate activities immediately adjacent to MPAs. This paper examines the legal regimes that exist to establish MPAs in Tasmania, New South Wales and areas under federal jurisdiction and the offences recognised to ensure the protection of ecological values. Those analysed are regimes set up under 'umbrella' MPA Acts, site-specific Acts and other legislative arrangements using existing fisheries legislation. It is concluded that a legislative system allowing the award of modest rather than severe penalties would increase the likelihood of prosecution and would complement educative measures aimed at ensuring compliance.