An alarming new study suggests that climate change is having some big effects on life deep below the ocean waves. The new research suggests that global warming has quaedrupled the number of dead zones in the ocean, which scientists warn could cause collapse of ecosystems.

Dead zones are areas of the ocean that are starved of oxygen, which can kill plants and animals are at least cause them to flee. The huge increase in the number of dead zones is yet another indication that climate change is having a dramatic effect on areas of the world we can’t see, thanks to a dramatic increase in greenhouse gases and agricultural runoff.

The study, published in the journal Science, claims that climate change caused by human activities is changing the biogeochemistry of the ocean and increasing the consumption of oxygen. This will cause tremendous economic and societal harm, they argue, when it eventually results in the collapse of ecosystems around the globe.

“Oxygen is fundamental to life in the oceans,” said Denise Breitburg, lead author and marine ecologist with the Smithsonian Environmental Research Center. “The decline in ocean oxygen ranks among the most serious effects of human activities on the Earth’s environment.”