The lack of oxygen in ocean water heralds a new mass extinction

I thought about the Mahdi

In the framework of an academic collaboration between the Georgia Institute of Technology, Yale University, the University of Portsmouth, the Czech University of Life Sciences in Prague and the Stanford School of Earth, Energy and Environmental Sciences (Stanford Earth), a team of researchers has strengthened the theory that the lack of oxygen in the oceans contributed to a devastating death about 444 million years.

The second largest mass extinction
The new findings also indicate that these “low-oxygen to zero-conditions” of it have lasted for more than three million years, a much longer period than the similar biodiversity extermination episodes our planet has witnessed.

The study, which was published in the "Nature Communications" on April 14, dealt with an event known as the Orduvichy mass extinction, which occurred about 450 to 444 million years ago, and is the second largest mass extinction the Earth has ever seen.

To classify this after the largest event, which is the extinction of the Triple Permian Age, known as the "Great Death", which occurred 251.4 million years ago, in which approximately 96% of all marine species and 70% of the wild vertebrates were eliminated.

The great events of extinction in the world are classified into five events, the most famous of which is the "Cretaceous - Paleogene" era that killed all non-bird dinosaurs about 65 million years ago.

The Ordovician era, which is the second of the six eras of the era of ancient life, lasted approximately 41.6 million years, preceded by the Cambrian, followed by Silurian, and was adopted internationally in 1960 by the International Union of Geological Sciences.

Aquatic world With the beginning of the late Ordovician around 450 million years ago, the world was a completely different place from what it is today, where different forms of life were restricted to the oceans only, to coincide with the beginning of the emergence of plants on Earth.

To read it, it forms the primitive supercontinent that included most of the continents that we know today, and it was called "Gondwana". Scientists believe that this extinction has two distinct peaks separated by nearly a million years.

The first climax started as a result of the global cooling that prevailed in the continent of Gondwana under glaciers, and then came the second climax of this extinction, which is due to the lack of oxygen in the oceans.

By the end of the late Orduvichy era, an estimated 85% of marine species had disappeared from the fossil record. The researchers focused on the second peak of this extinction to see what dissolved oxygen deficiency is and its impact on ocean biology as it is today. 

New model
The researchers developed a new model of data to study dissolved oxygen concentrations in ocean water. To include data of mineral isotopes that had been published in previous studies, in addition to new data from oil shale samples - which had been taken from the Murzuq basin in Libya - were deposited in the geological record during the late Orduvichy mass extinction.

The model studies a wide range of variables related to the properties of minerals, including the quantities of uranium and molybdenum that leak out from land and reach oceans through rivers to settle to the bottom.

Indeed, through this model, the researchers were able to demonstrate the lack of oxygen in the ocean waters that accompanied the second peak of the late Ordovishi extinction event, which made this era a bad time to survive.

Effects on biological diversity
This study aimed to understand the ancient events of mass extinction, and to compare them with what is happening today in an attempt to predict what will become of our planet.

The study concluded that the events of the great mass extinction witnessed by the planet Earth were characterized by a sharp decrease in the concentrations of dissolved oxygen in the ocean waters - which we are witnessing today - especially in the upper slopes of the continental plates, which represents a severe burden on many types of Organisms, and may cause some extinction.

This necessitates that researchers in this field conduct more intensive studies to model oxygen in ocean water today, with the aim of finding solutions that prevent a possible new mass extinction.