Effective coverage targets for ocean protection

When nations of the world agreed to establish national networks of marine protected areas (MPAs) at the 2002 World Summit on Sustainable Development, it was a major leap for ocean conservation. The UN Convention on Biological... [ view full abstract ]

When nations of the world agreed to establish national networks of marine protected areas (MPAs) at the 2002 World Summit on Sustainable Development, it was a major leap for ocean conservation. The UN Convention on Biological Diversity quickly added detail, setting a target of 10% of the sea as MPAs by 2012. Ten percent was a political, rather than a scientific target: not so little as to appear trivial, and not so much as to deter nations from signing up. Notwithstanding its modesty, the target was missed by a long way, but has been given new legs in UN Sustainable Development Goal 14, which wants 10% ocean protection by 2020. As we near this date, there are real hopes the target will be reached this time. However, scientific evidence now makes it clear that 10% is insufficient to achieve many of the desired goals for ocean management, such as recovering threatened species, representing biodiversity and supporting fisheries. Furthermore, a new purpose for MPAs has become appreciated: helping to mitigate and promote adaptation to climate change. Meeting such objectives will require higher targets and a figure of 30% protection by 2030 is being widely deliberated. The science, however, can equally well support another much-discussed target of 50% protection. Such figures are averages and do not apply equally to all habitats. Some habitats are so vulnerable to damage that any left unprotected will be lost, while others warrant greater precaution, like the high seas where governance is weak.