New study finds Australia's extinction tally is far greater than previously recognised

A new study estimates that between 1-3 species of insects and other native invertebrates like worms, snails and spiders, are becoming extinct in Australia every week, and about 9000 have become extinct since European arrival in 1788.

The findings reveal that Australia's loss of biodiversity is far greater than was previously recognised.

Among the extinctions, there are likely to have been many beneficial invertebrates, such as pollinators and species that are important for maintaining soil health like earthworms.

The Biodiversity Council and Invertebrates Australia have called the finding highly alarming and are calling on federal state and territory governments to increase work to understand, monitor and conserve Australia’s invertebrates.

The study was undertaken by a national team of 10 scientists from universities, museums and state governments, and was led by Biodiversity Council member Professor John Woinarski from Charles Darwin University.

According to Prof Woinarski, the study estimated the number of non-marine Australian invertebrate species — those without a backbone, like worms, beetles, bees and butterflies — that have become extinct since Europeans arrived in 1788.

“We found that 9,111 species are likely to have become extinct in those 236 years. Allowing for uncertainties and knowledge gaps, our analysis indicates that the true number is at least 1500 species and possibly up to 60,000 extinctions.

“This matters to every person as invertebrates are the foundation of all healthy environments and a livable planet. Invertebrates provide myriad essential functions that people depend on like pollinating crops and breaking down organic matter.

“As we lose invertebrates, the health of our crops, waterways, forests and even local parks and backyard gardens will decline.

“Only one of these extinctions has been formally recognised under Australian environmental legislation, that of the Lake Pedder earthworm. Most of the species became extinct before they were even described and named by scientists: the study calls these ‘ghost extinctions’.

“Despite their incredible importance there has been a long running bias against invertebrates, with little funding available for their research and conservation.

“This study indicates that the extent of loss of Australian biodiversity is far greater than has previously been acknowledged. In order to stem this rate of loss, our conservation efforts need to be more broadly-based.

“It is important that Australia’s federal and state and territory governments, and the community, give much greater priority to understanding, monitoring and protecting our invertebrates,” Prof Woinarski said.

Co-author Dr Jess Marsh from the University of Adelaide is a member of the Biodiversity Council and Invertebrates Australia.

“Thousands of invertebrate species remain at high risk of extinction,” said Dr Marsh, “But we don’t have to accept their losses as inevitable. There is a lot we can do to prevent extinctions, including by protecting important habitats and reducing threats, such as pesticide use.

“A first step is for people to be aware of the importance of invertebrates as the foundations of our natural world. And to be aware that many invertebrate species are at high risk of extinction and many have already been lost.

“It is great to see a growing recognition of the impact of pesticides and a move towards reducing their usage.

“We urge home gardeners to think carefully about reducing their pesticide use. Using pesticide in your garden often kills the beneficial invertebrates your garden needs like bees and flies that pollinate, lady beetles that help control aphids and worms that improve your soil.

“Many invertebrate species have already lost a huge amount of habitat and ongoing habitat loss remains a major threat.

“For example the golden sun moth occurs in south-eastern Australian grasslands. Even though little of the once vast grasslands remain they are still at high risk of being destroyed by developments.

“We found that species are also at greater risk of extinction if they only occur in a small area, need special habitat, or can’t easily move to other areas if their habitat is destroyed. Climate change will further exacerbate risks for such species.”