A study out of the University of Washington in Seattle shows that warmer ocean water temperatures and lower ocean oxygen levels will converge to force marine animals to migrate away from the equator to find regions of the world’s oceans with the oxygen supply that can meet their needs.
This study says that warmer water temperature will speed up the metabolic need for oxygen in these animals (which is something that naturally happens during exercise) and warmer water holds less oxygen than cooler water. It is kind of the same problem you might encounter when climbing to higher altitudes.
Furthermore, the study says that about two thirds of the respiratory stress from climate change may be caused by warmer temperatures and the rest is likely because warm water has fewer dissolved gases in it.
Deutsch used existing climate models to make this analysis, but he also goes on to note that if emission levels continue at their current level, the near-surface ocean will increase in temperature by several degrees (Celsius) by the end of this century.
“We found that oxygen is also a day-to-day restriction on where species will live, outside of those extreme events. Ranges will shift for other reasons, too, but I think the effect we’re describing will be part of the mix of what’s pushing species around in the future,” comments Deutsch.