The current biodiversity crisis in freshwater ecosystems is worse than that associated with the mass extinction event that killed the dinosaurs.
In a new report from the Naturalis Biodiversity Center, researchers warn that the damage being done today – in a relatively short timescale of decades to centuries – will take millions of years to recover from.
One of the most urgent challenges of this century is the ongoing biodiversity crisis, which is often referred to as the 6th mass extinction. According to the researchers, the rate at which we lose species today is unprecedented and has not been reached during major extinction crises in the past.
Both directly and indirectly, humans are pushing species beyond the limits of what they can survive. The major drivers of the biodiversity crisis include habitat destruction, climate change, overexploitation, pollution, and the introduction of invasive species.
An international team of experts led by the Justus Liebig University Giessen set out to investigate the extent of today’s biodiversity crisis by comparing it with the Cretaceous extinction event, which resulted from an asteroid impact 66 million years ago.
The Cretaceous extinction event wiped out about 76 percent of all species on the planet, including the dinosaurs.
The researchers focused on the impacts to freshwater animals. They analyzed a large dataset containing 3,387 fossil and living snail species of Europe covering the past 200 million years.
The study showed that the extinction rate for freshwater biota during the 5th mass extinction was considerably higher than what was previously believed. At the same time, the researchers found that this rate was drastically lower than what is predicted for the current 6th mass extinction event.
On average, the projected rate for the 6th mass extinction is three orders of magnitudes higher than during the time the dinosaurs went extinct. By 2120, a third of all living freshwater species are expected to have vanished.
“Losing species entails changes in species communities and, in the long run, this affects entire ecosystems. We rely on functioning freshwater environments to sustain human health, nutrition and fresh water supply,” said study lead author Dr. Thomas A. Neubauer.
The experts uncovered an alarming pattern in the 5th mass extinction event that could have dire consequences implications for the ongoing biodiversity crisis. After the asteroid impact, the extinction rate remained high for approximately five million years, and this was followed by an even longer period of recovery that lasted for millions more years.
According to the researchers, it took nearly 12 million years until the balance was restored between species emerging and going extinct.
“Even if our impact on the world’s biota stops today, the extinction rate will likely stay high for an extended period of time,” explained Dr. Neubauer.
“Considering that the current biodiversity crisis advances much faster than the mass extinction event 66 million years ago, the recovery period may be even longer.”
“Despite our short existence on Earth, we have assured that the effects of our actions will outlast us by millions of years.”
The study is published in the journal Communications Earth & Environment.