World fears on climate change are starting to come true. German scientists have now confirmed that the world’s oceans are losing their dissolved oxygen. This can spell dire consequences for the entire ocean ecosystem.
According to GEOMAR Helmholtze Ocean Research centre based in Germany, the world’s oceans have lost about 2 percent of their total oxygen content. While as such 2 percent sounds innocuous but if you take into account the fact that oxygen content varies from region to region, it means that certain parts of the world’s oceans have observed steeper drop in oxygen content as opposed to other regions.
Quite naturally, The Pacific Oceans being the world’s largest ocean has witnessed the greatest drop in oxygen volume whereas Arctic Ocean where climate change has played its biggest hands yet is observing the second largest drop.
It was previously assumed that dissolved oxygen rates were on the decline but such predictions were usually done on regional analysis. GEOMAR study is the first ever truly global look at ocean levels of dissolved oxygen and this one-of-a-kind study is now laying it bare for the world – climate change is affecting our oceans.
As you already have understood, dissolved oxygen content refers to the quantity of oxygen found in ocean waters. This is the oxygen dissolved in the water itself and it forms the lifeline for all marine creatures. Cold water is known to hold a greater amount of oxygen as opposed to warm water and fresh water. With climate change as glacial ice melts, the waters of the oceans heat up and freshen more regularly and this in turn leads to loss of dissolved oxygen.
Where does the ocean get its oxygen? Naturally, it absorbs oxygen from the atmosphere however, this is a slow process and it takes even longer for the oxygen absorbed at the surface to trickle down to the deeper layers of the oceans. Since, the upper layer of our oceans is hotter, it can retain less oxygen and this in turn affects the amount that trickles down to the lower levels.
The question now facing our marine biologists is how will this change in dissolved oxygen affect our marine life. The natural answer is that it will adversely affect marine habitats around the world but it could even affect coastal economies too. Based on current trends, predictions of how dissolved oxygen levels could change in future have shown a near 7 percent drop in its levels by 2100. The only real question now remains as to how the oceans will react to such a drastic change.