Journal Highlights

New study details ocean’s role in fourth-largest mass extinction


Extremely low oxygen levels in Earth’s oceans could be responsible for extending the effects of a mass extinction that wiped out millions of species on Earth around 200 million years ago, according to a new study.

By measuring trace levels of uranium in oceanic limestone that correspond to oxygen levels in seawater present during the rock’s formation, the new study finds areas of the seafloor without oxygen increased by a factor of 100 during the end-Triassic extinction event.

It took about 50,000 years for ocean oxygen levels to return to what they were before the extinction event and it may have taken as long as 250,000 years for coral reefs around the globe to fully recover, according to the study.

The new results shed light on the state of the oceans during the end-Triassic extinction, which wiped out approximately 76 percent of all marine and terrestrial species…More