The world’s oceans are on their last breath, according to a report by the International Union for Conservation of Nature written by 67 scientists from 17 countries. The findings were presented on the last day of global climate talks in Madrid, Spain, and show that oxygen levels in the world’s oceans declined by around 2 percent between 1960 and 2010. The main contributors are climate change and human activities such as nutrient run-off when fertilizers wash into waterways that end up in the oceans. The deoxygenation leads to a variety of threats to marine life. Dan Laffoley, an editor on the report warned that a 2 percent decrease is significant.

“We’re sort of sitting surrounded by plenty of oxygen and we don’t think small losses of oxygen affect us,” he said Saturday in Madrid. “But if we were to try and go up Mount Everest without oxygen, there would come a point where a 2 percent loss of oxygen in our surroundings would become very significant.” He also added that the ocean is not “uniformly populated with oxygen.” He sited one study from the journal Science that found that some parts of the tropics had seen up to 50 percent reduction in oxygen.