We do not believe that marine protected areas (MPAs) currently offer effective conservation in Australia. They do not address pollution or climate change (Nature 480, 151–152; 2011), and overfishing there has largely been rectified. MPAs are also inadequate for managing the major threat of introduced organisms, of which more than 400 have already been identified in Australian waters.

Terry Hughes' call to protect coral reefs from catch-and-release fishing (Nature 480, 14–15; 2011), by closing a further 480,000 square kilometres of ocean in Australia's Coral Sea in addition to the adjacent 507,000 km2 already proposed, is an example of exaggerated restriction of fishing. We contend that sustainable fisheries need to be expanded, not restricted.

Australia has well-managed fisheries but imports more than 70% of its seafood. By continuing to import while closing more of its exclusive economic zones to fishing, Australia is diverting pressure on seafood resources and the responsibility for their sustainable exploitation to other countries, most of which do not have Australia's effective governance of fishing.