The biggest marine news from the IUCN World Conservation Congress, held in Hawai’i in September, was the approval by IUCN members of a new global target for MPAs. It calls for “30% of each marine habitat” to be set aside in “highly protected MPAs and other effective area-based conservation measures” by 2030, with the ultimate aim being ”a fully sustainable ocean, at least 30% of which has no extractive activities.”

Readers of MPA News will notice the similarity to a recommendation that was made at the 2014 World Parks Congress in Sydney, which also called for a 30% MPA target. However, that earlier recommendation did not include a deadline. In addition it was not formally approved by IUCN’s membership, which comprises a mix of government agencies and NGOs.

On the new target, 129 member states and government agencies voted in favor, and 16 against (for background on countries that opposed it, go here). Among the NGO members, 621 were for and 37 against. IUCN’s members meet in plenary session every four years.

Although the 30%-by-2030 target is not binding on nations, it does represent the most ambitious target adopted so far for the MPA community. As has been seen with Aichi Target 11 — which calls for 10% MPA coverage by 2020 under the UN Convention on Biological Diversity — such percentage-based targets have helped motivate governments to designate MPAs. The latest global assessment by IUCN finds that 10.2% of waters within national jurisdictions are now in MPAs — an increase of 1.8% in just the past two years. (For the entire global ocean including high seas, MPA coverage is at 4.1%.)

Debating percentage-based targets

MPA News has covered percentage-based goals for MPAs since 2000, when they first began to appear in policies. Although they may have little bearing on the day-to-day management of MPAs, they provide a simple (some might say simplistic) indicator of progress across the field. And they provide a relatively tangible goal for planners and negotiators.

That is not to say that such targets are not controversial. They have always spurred debate. Letters to MPA News 15 years ago suggested such targets were based more on politics than science and similar arguments were made by target opponents at the World Conservation Congress (WCC). Several scientists have argued otherwise, including in studies that were cited in the IUCN motion for 30% coverage.

A new article in the journal Aquatic Conservation (“‘Dangerous Targets’ revisited: Old dangers in new contexts plague marine protected areas”) suggests percentage-based goals can give the illusion of progress, and that actual outcomes for conservation and planning do not always measure up. As one example of this: roughly one-fourth of US national waters are in MPAs, yet almost all of that MPA area (96%) is around relatively remote tropical Pacific islands, not around the temperate continental US.

Graham Edgar, who described five characteristics that determine MPA effectiveness in a 2014 study (i.e., no-take; enforced; older than a decade; larger than 39 square miles; and isolated by deep water or sand), says ambitious targets reward governments for creating large MPAs in locations where no or few users are operating. “If the caveat ‘of each habitat’ in the WCC 30% target is ignored, as seems likely, the net result is that maritime business can continue as usual, with negligible reduction in environmental pressures,” he says. “Overall, we are heading towards good MPA protection of isolated tropical systems, and little protection in populated temperate regions with unique but threatened biodiversity that continues to decline.”

That being said, Edgar acknowledges that two of the five factors he identified for MPA success — large and isolated — are consistent with big, remote MPAs. In that sense, expansive targets that catalyze more large MPAs will increase the number of effective MPAs worldwide. “However, a set of MPAs that are individually effective ticks only part of the requirement for an effective global network,” he says. “In addition to effectiveness, comprehensiveness is also needed, making sure that all MPA eggs are not placed in one ecosystem basket.”

The next horizon: 50% MPA coverage?

The controversial nature of percentage-based targets has not stopped some from reaching for even higher goals than 30%. At the World Conservation Congress, calls for 50% MPA coverage came from several high-profile speakers, including oceanographer Sylvia Earle and biologist Edward O. Wilson. Wilson published a book this year titled Half-Earth: Our Planet’s Fight for Life, in which he argues that to stave off a mass extinction of species, half of the planet’s land and water should be dedicated to nature. The separate Nature Needs Half campaign, coordinated by WILD Foundation, has made similar arguments for several years.

In turn these calls may be supported by a sobering new IUCN report on ocean warming, which documents that species and habitats are already shifting due to climate change, and that these will challenge the current borders of MPAs. As a result, the report concludes, significantly larger MPAs and MPA networks, as well as the ability to change boundaries, will likely be needed.

The call for 50% MPA coverage has even been echoed by the executive secretary of the UN Convention on Biological Diversity, Braulio Ferreira de Souza Dias.  In a high-level panel on oceans at the World Conservation Congress (video here), Dias gestured toward Edward Wilson in the audience and said, “I’m confident that we’ll get to half-Earth. I think what Professor Wilson proposed is feasible, and we should be looking at that as a more mid- [to] long-term goal. We have the knowledge.”

Getting to 50% MPA coverage — even moreso, 50% no-take coverage — would require a seismic change in political attitudes. We are nowhere near that figure: current global MPA coverage remains just a fraction of it. But progress toward the 10% Aichi target is being made.

Past MPA News coverage of percentage-based targets: