Marine reserves help mitigate against climate change, say scientists

Scientists say reserves can help marine ecosystems and people adapt to five key impacts of climate change: ocean acidification; sea-level rise; increased intensity of storms; shifts in species distribution, and decreased productivity and oxygen availability.

Reserves also can promote uptake and long-term storage of carbon from greenhouse gas emissions, especially in coastal wetlands, which helps reduce the rate of climate change, the study revealed.

The study, published in the Proceedings of the National Academy of Sciences, evaluated existing peer reviewed studies on the impact of marine reserves around the world.

Currently, only 3.5 per cent of the ocean has been set aside for protection with just 1.6 per cent fully protected from exploitation.

International groups are working to raise the total to 10 per cent by 2020, while delegates to the International Union for the Conservation of Nature's 2016 World Conservation Congress agreed that at least 30 per cent should be protected by 2030.

Scientists say Marine Reserves and Marine Protected Areas (MPAs):

• Protect coasts from sea-level rise, storms and other extreme weather events
• Help offset climate-change induced declines in ocean and fisheries productivity
• Provide refuges for species as they adjust their ranges to changing conditions
• Can help combat acidification

Lead author, Professor Callum Roberts from the University of York's Environment Department, said: "Many studies show that well-managed marine reserves can protect wildlife and support productive fisheries, but we wanted to explore this body of research through the lens of climate change to see whether these benefits could help ameliorate or slow its impacts.

"It was soon quite clear that they can offer the ocean ecosystem and people critical resilience benefits to rapid climate change."

Previously published research revealed that marine reserves can promote rapid recovery of exploited species and degraded habitats while safeguarding intact ecosystems.

These benefits are greater in large, long-established, well-managed reserves that have full protection from activities such as fishing, oil and mineral extraction. Relative isolation from damaging human activities adds further conservation benefits.

The ability of protected areas to offer strong climate change resilience benefits is likely to be contingent on these characteristics.

The research shows that protecting more of the ocean will also improve the outlook for environmental recovery after greenhouse gas emissions have been brought under control. This strengthens the case that the United Nations ocean protection target be raised from 10 per cent to 30 per cent coverage of MPAs, which will require many more large-scale MPAs and protected areas beyond national jurisdiction.

Beth O'Leary, a co-author and Research Fellow at the University of York, added: "We were keenly aware that marine reserves can increase species' abundance and help alleviate food scarcity, but our evaluation showed reserves are a viable low-tech, cost-effective adaptation strategy that would yield multiple co-benefits from local to global scales, improving the outlook for the environment and people into the future."

Matt Rand, Director of the Pew Bertarelli Ocean Legacy Project, which supported part of the research, added: "This study should be proof positive to decision makers that creating effectively managed marine reserves can deliver a multitude of benefits. Marine reserves are climate reserves."