Nearly three percent of the world's oceans – an area slightly larger than Europe – now lies within designated marine protected areas, according to new data from the International Union for Conservation of Nature (IUCN). This is a significant increase from 2010 when the area protected was just 1.2 per cent. However, many of the new protected zones may be of little value in terms of conservation.

The IUCN, which yesterday released the latest official map of marine protected areas (MPAs), defines a protected area as "a clearly defined geographical space, recognised, dedicated and managed, through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services and cultural values". In practical terms, this can mean implementing measures to restrict the amount of fishing and mineral exploitation that can take place in the waters, for example.

The rapid increase in coverage of MPAs means that the world should soon be able to meet the UN Convention on Biological Diversity target of having 10 per cent of the oceans protected. "It's encouraging to see the progress we've made so far," said Carl Gustaf Lundin, director of the IUCN's Global Marine and Polar Programme. "If we continue to increase this area by one per cent each year, we should be able to reach the agreed 10 per cent by 2020."
Antarctic talks

We may get even closer to meeting the target when the results of negotiations to create huge marine reserves around Antarctica – which would include some of the world's last remaining pristine waters – are announced next week. The MPAs being discussed in Hobart, Australia, would introduce a ban on fishing in the spawning areas of some species and put limits on the amount of fish caught elsewhere. If the proposals being discussed are agreed on, the global protected area will jump by about another percentage point.

But a preoccupation with the size of MPAs is counterproductive, says marine conservationist Bob Pressey from James Cook University in Townsville, Australia. "It's the wrong measure." He says conservation only occurs when a threat, such as species loss from overfishing or pollution, has been mitigated. Many of the protected areas do not enjoy sufficient enforcement.

The largest network of marine reserves in the world is around Australia, and was significantly added to in 2012. Pressey points out that many of those areas allow oil and gas exploration, while others allow recreational fishing.
Motivated by numbers

The focus on the 2020 target means governments are motivated to protect the low-hanging fruit – large areas that are of little conservation value or that are not under any threat, Pressey says.

"If you look at the no-take zones [off Australia], you find them way offshore in deep water and you find them in areas with no oil or gas interest," he says. "In the world map, we see a repetition of that. The big MPAs are remote as hell," he says.

Hugh Possingham from the University of Queensland, who together with Pressey built the open-source software that countries use to design MPAs, agrees. "We don't want countries just bragging about the size and percentages. There's more to this than size," he says. One important factor is that an example of each type of ecosystem in a country's waters should be protected, such as mangrove forests or salt marshes, but this effort is often perverted by commercial interests, he says.

Pressey says the Antarctic MPAs currently being negotiated would be a valuable addition because of the region's important biodiversity – the Ross Sea, for example, boasts orcas, minke whales, seals, Adélie and emperor penguins – and the threat the area faces from overfishing.