A team of researchers has found that climate change is causing oceanic oxygen concentrations to drop, potentially disrupting ocean ecosystems. A decrease in available oceanic oxygen could also have financial impacts in coastal areas since it could negatively affect fisheries and tourism. The details are in a paper that was just published in the journal Nature.
Scientists have recently been publishing a large number of studies on climate change and how it will affect both wildlife and human populations. Human activities result in the production of greenhouse gases, including carbon dioxide, methane, and nitrous oxide. These types of gases trap heat from the sun, triggering a global warming. Sudden rises in global temperatures can lead to rapid environmental changes and extreme weather patterns. Better understanding the sources and impacts of these problems may aid in the development of mitigation plans.
Researchers from the GEOMAR Helmholtz Centre for Ocean Research Kiel in Germany analyzed data on oceanic oxygen concentrations from the last several decades. Dissolved oxygen is necessary to support most aquatic life so any sudden drops could be devastating to ocean ecosystems. Although there have been smaller studies on the loss of dissolved oxygen, this was the first study conducted on a global scale. The team used their data to predict how oceanic oxygen concentrations would change over time, assuming climate change stays on its current path.
The research team found that their models predicted a drop in oceanic oxygen by up to 7% by the year 2100. This may not sound like a huge decrease but it would be enough to kill or seriously harm most sea life, including fish species that humans rely on for food. The ocean already contains just enough oxygen to support marine wildlife. Further exacerbating the problem is the fact that warm water can’t hold onto as much dissolved oxygen as cooler water. This means that as the ocean heats up, it will lose oxygen without being able to replace it. The team predicts that this will cause serious problems in coastal regions that rely on marine tourism and fishing for income, assuming no actions are taken to mitigate global warming.
Schmidtko et al. Decline in global oceanic oxygen content during the past five decades. Nature (2017).