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Marine Life Around Antarctica Has Returned To Its Pre-extinction Levels

Study delves into how marine life around the region recovered following the dinosaur’s extinction, and finds that it took one million years for the ecosystem to return to pre-extinction levels.

Antarctica marine ecosystem has made an astounding recovery. In a study that looked into marine fossils collected from once the deepest depth of Antarctica to see how life on the sea floor bounced back following the the Cretaceous-Paleogene extinction event, a team at British Antarctic Survey revealed that the marine life has returned to its pre-extinction levels.

The Cretaceous-Paleogene extinction event, also known as the K-Pg extinction, accounted for obliteration of 60 percent of the marine species around Antarctica, and 75 percent of other species around the world. Victims included the dinosaurs, the ammonites and a wide range of other flora and fauna.

The evidence directs at the impact of a 10 km asteroid on the Yucatán Peninsula of Mexico, and it transpired during a period when the Earth was under stringent confrontation of environmental instability incited by major volcanic episode. The event ensued rapid climate change, caused global darkness, and crumbled food chains which affected life all over the globe.

The event had a profound impact on the evolutionary history of life on Earth. Most species that dominantly thrive in these modern ecosystems today began to develop after this event.

A team at British Antarctic Survey revealed that the marine ecosystem around Antarctica has returned to its pre-extinction levels. They studied nearly 3000 fossils. [Image:  Rowan Whittle  via BAS]
A team at British Antarctic Survey revealed that the marine ecosystem around Antarctica has returned to its pre-extinction levels. They studied nearly 3000 fossils. [Image: Rowan Whittle via BAS]

To study how the ecosystem recovered after the event that wiped out the dinosaurs 66 million years ago, researchers studied around 3000 marine fossils found near the South Pole. They also showed that for over 320,000 years after the extinction, the Antarctic seabed were inhabited by burrowing clams and snails. Then it took up to one million years for the number of species to recover to pre-extinction levels.

Researchers also highlighted that the inhabitants in the region were confined to harsh living conditions and had to endure continual darkness, ash fall and lack of food for years. But with the extent of the catastrophe, it was impossible for local ecosystem to get back on its feet for hundreds of thousands of years.  

“This study gives us further evidence of how rapid environmental change can affect the evolution of life,” says Dr Rowan Whittle, a palaeontologist at British Antarctic Survey. “Our results show a clear link in the timing of animal recovery and the recovery of Earth systems.”

“Our discovery shows the effects of the K-Pg extinction were truly global, and that even Antarctic ecosystems, where animals were adapted to environmental changes at high latitudes like seasonal changes in light and food supply, were affected for hundreds of thousands of years after the extinction event.” says Dr James Witts, a palaeontologist at University of New Mexico”

The study has been published in the journal Palaeontology, and it’s titled “Nature and timing of biotic recovery in Antarctic benthic marine ecosystems following the Cretaceous–Palaeogene mass extinction”

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