The dead zone

NASA recently published a worrying image showing the spread of oceanic dead zones across the globe. Now, researchers in Austria have for the first time shown how the behavior of marine creatures that live on the ocean floor can help us predict the development of these dead zones based on competition for oxygen. Regions of the oceans that lack the necessary oxygen concentration to sustain life are increasingly common, there are 400 known dead zones that have been recorded so far amounting to an area of ocean greater than 250,000 square kilometers, almost the area of the US state of Nevada. The causes are likely to be manifold: climate change, pollution, and other natural factors may be to blame. The researchers have built a catalog of animal behavioral models that are manifest when oxygen levels are lower than normal, which could be used to classify threatened marine environments.