The oxygen supply in our oceans is maintained by interactions between the surface of the ocean and our atmosphere. The upper ~700 feet of the ocean absorb sunlight allowing photosynthesis to take place, which produces oxygen. This oxygen can then be circulated through the ocean by wind and waves and transferred to the deeper parts of the ocean.

Oxygen leaves the ocean by evaporation and is also consumed by marine life. In a perfect world, these processes are in a constant balance and oxygen is well circulated throughout the ocean allowing for marine life to flourish at a range of depths. But, as atmospheric temperatures on Earth continue to rise due to our changing climate, ocean temperatures have also begun to rise. Rising ocean temperatures have been shown to cause widespread “deadzones” in our oceans.

These “deadzones” are areas in which there is little to no oxygen and they are growing rapidly and pose a huge threat to marine life. As atmospheric temperatures rise, ocean temperatures also rise and as a result more and more oxygen is being depleted from our oceans; warming oceans slow the rate of ocean circulation, so less oxygen is reaching great depths suffocating marine life living at these depths.

Warming oceans also increase the rate of evaporation, increasing the rate of oxygen loss. Warming temperatures and decreasing oxygen levels in the oceans put a lot of stress on marine organisms. This current imbalance of oxygen levels in our oceans is likely in part a result of human-induced changes to our climate. Although oxygen may never completely run out, it is being severely depleted due to climatic changes that are throwing off the ecological balance that maintains steady state oceanic oxygen levels.

So, some areas of the our oceans, and lakes as well, can run out of oxygen.