Are we still protecting the right places in the ocean?

According to the World Database on Protected Areas, the ocean now counts more than 18,000 marine protected areas (MPAs) globally, covering an estimated 8.16% of the sea. Well-managed MPAs are a cornerstone of ocean conservation. With some of the early MPAs maturing now, evidence shows that highly protected MPAs – especially no-take zones where no fishing, mining, drilling or other extractive activities are allowed – protect, recover and restore biodiversity and ecosystem services, creating multiple benefits for both nature and people.

A recent study in Science, for example, confirmed there was a 54% catch rate increase for yellowfin tuna and an 8% catch rate increase for all fish species combined, at the protected 583,000 square-mile Papahanaumokueakea of the Northwestern Hawaiian islands, since its creation as an MPA and inscription on the UNESCO World Heritage List in 2010. Similar positive results are emerging in other marine protected areas worldwide. But what is good for ocean biodiversity is also good for human and planetary health.

Ocean biodiversity delivers many ecosystem services beyond its captivating beauty. It plays a significant role in storing carbon and provides crucial protein for the world’s rising food needs. The ocean’s fantastic biodiversity and many yet-discovered species are also a prosperous source for new medicine with promising test results in cancer treatment, among other medications. Protecting ocean biodiversity is not optional; it’s essential to the health and well-being of the global population, now and in the future.

The COP15 of the United Nations Convention of Biological Diversity in Montreal, Canada, from 7 to 19 December, expects to set new international targets for marine protected areas. Currently, through the United Nations Sustainable Development Goal 14 and the Convention on Biological Diversity’s Aichi Target 11, nations seek to effectively protect 10% of the ocean by 2020. However, there are calls for a new target to protect at least 30% of the global ocean in MPAs by 2030.

Setting ambitious targets and creating new MPAs is hugely important. But seen from the vantage point of our role at UNESCO in overseeing the conservation of 50 MPAs inscribed on the UNESCO World Heritage List in 37 countries, a crucial question needs urgent attention: are we still protecting the right ocean places?

Across these 50 marine protected areas , climate change is increasingly altering local biodiversity. Invasive species, for example, have become a key driver in disrupting native biodiversity. Some two-thirds of UNESCO marine World Heritage sites struggle with the problem. For example, a recent visit to the Wadden Sea World Heritage area, which borders the Netherlands, Germany and Denmark and hosts the world’s largest tidal flats, revealed how the pacific oyster is rapidly invading blue mussel beds due in part to rising ocean temperatures.

Furthermore, it is causing increasing food shortages for the 12 million birds that feed there yearly on their migration journeys from the Arctic to Northern Africa.

When extrapolated at a global scale, warming waters are set to cause major geographic shifts in fish and other species in the coming decades. A study conducted with the data of 800 fish and invertebrate species from the world’s largest open-source ocean biodiversity information system (OBIS) showed that species are predicted to shift on average 25 kilometres per decade from the equator toward polar regions under a high emissions climate scenario, which will lead to significantly altered patterns of species richness in higher latitude areas and drastic extinctions in marine biodiversity around the equator.

While there are many reasons why fish and other marine species move, climate change is accelerating this trend with unprecedented speed and poses serious questions about which areas require what type of protection, how to draw the boundaries of new MPAs and where to adjust those of existing ones.

Today most marine protected areas lack the finer-scale data and information that could inform such decisions. In this context, UNESCO embarked on a global, two-year citizen science initiative through which fish species and other marine biodiversity are sampled across 25 of the world’s most exceptional MPAs using environmental DNA methods. Combined with IPCC heat projections, the initiative is expected to provide initial insights into where fish species might move and how present and future MPA boundaries might need to be thought out differently to remain relevant in a rapidly changing ocean.

While new marine protected areas are urgently needed – especially large and highly protected MPAs – having them in the right places will make all the difference for the future of ocean biodiversity and, by extension, our health, food security and climate.