The oceans may be on the verge of biological collapse, according to sobering new research from UC Santa Barbara. The researchers believe that marine life may suffer extinctions not seen since the end of the Cretaceous period. Given the horrendous damage inflicted on the oceans— climate change, acidification, plastic pollution, industrial trawling, coastal destruction, etc.,— it’s hard to argue with that conclusion. However it may not be too late to turn things around. The proposed solution, a series of large ocean reserves, designed with climate change in mind, poses its own challenge. Can it work?

All else being equal, yes, marine reserves do work. A paper in Ecological Applications found that no-take reserves (where absolutely no exploitation is allowed) not only had higher density and diversity of marine life within the reserve but also in surrounding unprotected areas surrounding.

Paradoxically, limits to fishing in some areas may actually improve fisheries elsewhere, improving livelihoods and support for the reserve. The need for proper enforcement is a given, as the density of fish in and around a reserve can be very attractive to poachers.

However, to protect the entire ocean you’re going to need a bigger reserve. Some reserve networks are already planned or in effect, but reserves covering much of the ocean will need to be transnational, raising a host of new issues. Some of these issues were explored in a 1998 article in Conservation Biology, examining the feasibility of open ocean, international pelagic (not in contact with land) reserves. Some of the obstacles include the need for international cooperation on research, enforcement, and the all-important question of where best to establish such a reserve network in the first place.

The 1998 study is good at identifying problems and broad solutions but is light on specifics. The authors list few actionable ways to achieve an international pelagic network, but they do point out that the multinational administration of Antarctica has been relatively successful. There is precedent for international cooperation on a large scale in natural resource management.

The problem hanging over this idea is uncertainty. Marine reserves work, but they are set in the places where they are most effective now, not necessarily where they will be most effective in 20 years. Without knowing the exact magnitude of the problem it is nearly impossible to predict where that will be.

For this idea to work, reserves will need to shift, grow, and evolve as conditions change, requiring unprecedented international agreement. The framework for future adaptability needs to be set up now, whatever disagreements between nations exist.