Will the oceans one day run out of the oxygen that marine life relies on to survive? Experts seem to think so.
In a recent study that was published in Global Biogeochemical Cycles, global warming could be causing more than just melting ice at the Northern and Southern tips of our planet; it could also be causing our oceans to lose their oxygen supply faster than it can be replenished by natural sources.
Among those natural sources are at the water’s surface, and from phytoplankton. The only problem is, warmer water isn’t as good at absorbing oxygen as colder water is, and this means less oxygen penetrates the water’s surface and gets deeper into the water where the animals reside.
"Loss of oxygen in the ocean is one of the serious side effects of a warming atmosphere, and a major threat to marine life,” said lead author Matthew Long of the National Center for Atmospheric Research (NCAR).
“Since oxygen concentrations in the ocean naturally vary depending on variations in winds and temperature at the surface, it's been challenging to attribute any deoxygenation to climate change. This new study tells us when we can expect the impact from climate change to overwhelm the natural variability.”
The ocean’s life relies on the oxygen in the water to survive. Although fish don’t come up the surface to breathe, their gills filter out the oxygen from the water and replace it with carbon dioxide. When oxygen levels drop, fish don’t get the oxygen they need.
In some parts of the ocean, this is already happening; namely the Pacific Ocean. The authors of the study believe, however, that the problem will become “widespread” and “noticeable” across the rest of the world’s oceans by the 2030’s or 2040’s.
"We need comprehensive and sustained observations of what's going on in the ocean to compare with what we're learning from our models and to understand the full impact of a changing climate," Long said.
The idea that oxygen levels are dropping in our oceans is alarming because it could pose a threat to part of the world’s essential oceanic ecosystem. Fish are a huge part of the food chain, not only for other fish and sea creatures, but also for birds, and even people.