In the World’s Oceans, Wildlife Is Disappearing Faster Than on Land

As temperatures increase around the world, marine animals are more vulnerable to extinctions than their counterparts on land, according to a new analysis of hundreds of cold-blooded species.

With fewer ways to seek refuge from warming temperatures, ocean-dwelling wildlife are disappearing from their habitats at twice the rate of those on land, notes the research published in the journal Nature. The study is the first to compare the impact of higher temperatures in the ocean and on land for a range of cold-blooded animals.

Previous research has shown that warm-blooded animals are better suited to adapt to climate change than cold-blooded species. As the oceans continue to heat, bringing waters to their warmest point in decades, wildlife in the seas don’t have the luxury of escaping into the shade or a burrow.

The scientists calculated “thermal safety margins” for 88 marine and 318 terrestrial species, determining how much warming they can tolerate. The safety margins were slimmest near the equator for ocean wildlife and near to the midlatitudes for land animals.

For many species, the heat is already too much. At the warm edges of the marine species’ ranges, more than of half the species have disappeared from their historical territory. The rate for these localized extinctions is double what is seen on land.



Photo: “Green Sea Turtle” by Papahānaumokuākea Marine National Monument is in the Public Domain