A small snail believed to have been accidentally found in Tasmania’s yingina/Great Lake


A small snail thought to be extinct has been found by accident in Tasmania’s yingina/Great Lake, having not been seen since the 1900s.

the Beddomeia tumidaa freshwater snail measuring around 4mm, was found as part of conservation monitoring of the lake by Entura, a branch of Hydro Tasmania.

The chance find in the central plateau lake was the first time the snail had been seen or recorded in over 120 years.

Andy Taylor, environmental scientist at Hydro Tasmania, said the snail was found by accident as the team searched for another thought to be extinct species – the giant Great Lakes freshwater limpet.

Zoologist Dr Karen Richards helped identify the snail.(Supplied: Hydro Tasmania)

“He’s been in the dark for a while now,” he told Helen Shield on ABC Radio Hobart.

“We know very little about the ecosystem [at Great Lake]. It’s fascinating and understudied.

“We would really like to learn more about the snail and try to get a sense of its abundance.”

The snail has been listed as “Critically Endangered but Possibly Extinct” by the International Union for Conservation of Nature Red List and is only found in yingina/Great Lake.

An elusive snail

The limpet the team was looking for was discovered during a survey when the lake was at a historic low in 2015 and 2016, and researchers returned and found it last year when the lake was full. .

Low water levels in the Great Lake in central Tasmania
The dry conditions caused water levels at the Great Lakes Dam to drop to unprecedented lows in 2016, but allowed researchers to investigate.(Provided: Kaylee Hattinger)

Late last year they got some old roof tiles from the tip shop along with ropes and buoys to drop into the lake 2-10 meters to see if any limpets or other creatures from the background would cling and call the tiles home.

In 10 days, they not only found the limpet, but also the elusive snail.

Entura water quality consultant Kevin Macfarlane led the investigation and said so far 15 snails had been found.

“Once we have an idea of ​​the size of the population, it could potentially be classified as not critically endangered, and hopefully we will find it to be abundant,” he said. he declares.

“As Beddomeia species are not present in places where the water quality is poor. This tells us that the water quality is very good and the habitat is very good.

A small snail sitting on a brown tile
The roof tiles of the tip shop proved to be a pleasant home for the snail and the limpets.(Supplied: Hydro Tasmania)

“Tiny” chance of finding a snail

At first, Mr Macfarlane did not know what species it was when he pulled it out and had it officially identified by zoologist Dr Karen Richards from the Department of the Environment.

When he received the text saying it was the missing species, he said it was “really exciting”.

“I was extremely happy,” he said.

a small black snail with the finger for comparison
The snail measures only 4 mm.(Supplied: Hydro Tasmania)

Mr Macfarlane said he had been trying to find the snail for nine years.

“We hoped he was there and tried to look for him, but we couldn’t find him,” he said.

He said that in the 1990s shellfish experts spent a lot of time trying to find the snail, but without success.

Great Lake is Australia’s second largest natural lake and has been modified to a size of 176 square kilometres.

A drone of a lake.
The Great Lake in the central highlands of Tasmania.(ABC News: Craig Heerey)

Mr Macfarlane dropped 100 tiles on ropes all over the lake, but finding anything was a needle in a haystack mission.

“The odds of any of them crawling on them are slim,” he said.

Given the record highs of 2015-2016, Mr Macfarlane said the people of the lake must be very resilient.

Investigations also uncovered other undescribed snail species, sponges, an aquatic plant and a clover-like grass that hadn’t been seen in 20 years.

The lake was the first source of water for Hydro Tasmania and was dammed in 1901 causing its level to rise.

It initially supplied the Waddamana Power Station, which was operated by the state-owned Hydroelectric Department from 1916 to 1964, and was replaced by the Poatina Power Station in 1966.


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