Global warming could wipe out many of the animals living in protected parts of the world's oceans by the end of the century, scientists predict.

Polar bears and penguins are among the species under greatest threat.

Projections suggest that by the year 2100, Marine Protected Areas (MPAs) will be 2.8C (37F) warmer than they are today if the levels of emissions carry on as expected.

A new study published in the journal Nature Climate Change suggests that without drastic action MPAs - and the fish, mammals, birds and invertebrates now dwelling within them - will be "devastated" by rapid global warming.

There are 8,236 MPAs around the world. They make up 4% of the total surface of the oceans.


"With warming of this magnitude, we expect to lose many, if not most, animal species from Marine Protected Areas by the turn of the century," warned lead scientist Professor John Bruno, from the University of North Carolina in the US.

The scientists carried out simulations of sea surface temperatures and oxygen concentrations in MPAs around the world, including those where fishing is banned.

Image: Polar bears could face extinction, researchers say

They found that even under the Intergovernmental Panel on Climate Change (IPCC) "business-as-usual" emissions scenario, MPAs were expected to warm by 0.034C (32F) per year.

By the end of the century, ocean temperatures in MPAs will have increased by an average of 2.8C (37F), they said.

For each MPA the scientists calculated the critical point after which most species would not be able to tolerate further change in their living conditions.

In tropical areas, this threshold was expected to be reached by about 2050.

MPAs in the Arctic and Antarctic were among those at greatest risk, said the scientists.

Other high-risk MPAs included those off the northern Galapagos islands Darwin and Wolf.

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