Current extinction rate in European freshwater gastropods greatly exceeds that of the late Cretaceous mass extinction

Thomas A Neubauer,Thomas Wilke,Jens Schauer,Mathias Harzhauser,Daniele Silvestro,Torsten Hauffe,Dietrich Kadolsky,Frank P Wesselingh

doi:10.1038/s43247-021-00167-x

Abstract

The Cretaceous–Paleogene mass extinction event 66 million years ago eradicated three quarters of marine and terrestrial species globally. However, previous studies based on vertebrates suggest that freshwater biota were much less affected. Here we assemble a time series of European freshwater gastropod species occurrences and inferred extinction rates covering the past 200 million years. We find that extinction rates increased by more than one order of magnitude during the Cretaceous–Paleogene mass extinction, which resulted in the extinction of 92.5% of all species. The extinction phase lasted 5.4 million years and was followed by a recovery period of 6.9 million years. However, present extinction rates in European freshwater gastropods are three orders of magnitude higher than even these revised estimates for the Cretaceous–Paleogene mass extinction. Our results indicate that, unless substantial conservation effort is directed to freshwater ecosystems, the present extinction crisis will have a severe impact to freshwater biota for millions of years to come.

Highlights

The Cretaceous–Paleogene mass extinction event 66 million years ago eradicated three quarters of marine and terrestrial species globally
Based on the rich European gastropod fossil record, we show that freshwater extinction at the K–Pg boundary was severe and has been underestimated so far
Previous studies based on the global vertebrate fossil record reported freshwater species extinction levels of 10–22%25

Summary

Introduction

The Cretaceous–Paleogene mass extinction event 66 million years ago eradicated three quarters of marine and terrestrial species globally. Biodiversity in freshwater ecosystems is disproportionally high: while only covering 1% of the Earth’s surface, they account for about 10% of the global species richness[1] These environments and their biota provide invaluable ecosystem services sustaining human health, nutrition and fresh water supply[2,3]. The current biotic crisis is widely considered the onset of a major extinction event, the so-called ‘6th mass extinction’[17,18] It resembles in several aspects the 5th mass extinction at the Cretaceous–Paleogene (K–Pg, formerly K–T) boundary 66 million years (Myr) ago. Both biotic crises are in geological timescales catastrophic events—an asteroid impact in the end-. Cretaceous versus human impact during the Anthropocene, both paired with a steep rise in CO2 and global temperature[19,20,21,22,23,24]

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