It’s not too late to stop the mass extinction in the ocean


Species that already live near the poles are less likely to have somewhere to move when their oceans begin to warm. This is why, in the model of Deutsch and Penn, species towards the poles tend to disappear completely while tropical species are more likely to move away from the tropics. “You have this potential for this changing of the guard,” Rutterford says.

Scientists know this movement is happening today, but it’s hard to pinpoint how bad things are right now. For starters, we don’t have a clear picture of what’s going on in our oceans. Many of the best fish abundance data come from studies of commercially important fish species, such as tuna and pollock, while data for tropical species are much scarcer. “If you really want to know what’s happening at the equator, we need equator studies,” says Rutterford.

“There are silent extinctions that are almost certainly happening in the oceans that are going undetected right now. And that wave of undetected extinction is going to become a tsunami if climate change is allowed to progress,” McCauley says.

Even though we have climate change under control, humans still put extreme pressure on the oceans due to fishing and changes in marine habitats. In 2008, the International Union for Conservation of Nature reported that 22% of assessed marine species were threatened with extinction, including 17% of sharks and their close relatives. One of the ways governments and NGOs have agreed to protect the oceans is to turn large swathes of them into marine protected areas – an ocean equivalent of national parks.

“Marine protected areas are our best protection because in the face of the unknown, they allow us to catch our breath,” explains Katrina Davis, conservation biologist at the University of Oxford. In October, members of the United Nations Convention on Biological Diversity will meet to finalize their goals for protecting biodiversity on the planet. One of the main proposals is a plan to set aside at least 30% of land and sea areas as protected areas. Protecting coastal areas is particularly important, Davis says, because it’s one of the main places where humans and marine species come into conflict.

But marine protected areas will only be a temporary solution if we let climate change spiral out of control, says McCauley. “You don’t want to try to solve local threats to diversity and just let climate change undo all of that in the future.” A return to the Great Death is far from inevitable, but every fraction of a degree of warming we can stop will reduce the severity of ocean extinctions. “Our main result is that the magnitude of future extinction depends on CO2 shows are moving forward,” Penn says. “This story is not yet written.”

More Great WIRED Stories


Comments are closed.