Mary River turtle added to world’s most endangered list

By Elizabeth Arrigo 12 April 2018
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This isn’t the first time the Mary River turtle has been issued a red alert.

Recognisable by its algal facial hair and revered by scientists for its bizarre bum-breathing mechanism, the Mary River turtle (Elusor macrurus) has sadly been added to the Zoological society of London’s endangered list.

Back in 2010, Australian Geographic reported that populations of these unique turtles, found only in south-east Queensland’s Mary River, have dropped by almost 95 per cent.

While the Mary River turtle is a new edition to this particular list, falling population numbers and threats to the species have been documented since the 1960s.

Today, their number one threat is the plundering of their nests by dogs, foxes and goannas.

Grazing and land clearing near the Mary River has also proved detrimental for the turtle, resulting in lower water quality and a build-up of silt.

Adding to the turtles’ woes, invasive plants along the river bank has contributed to a lack of breeding success as they make it difficult for the Mary River turtles to go ashore and lay their eggs.

The combination of these threats has secured the Mary River turtle 30th place on the ZSL’s Evolutionarily Distinct and Globally Endangered (EDGE) list for reptiles, a list of most vulnerable reptile species around the globe.

Edge lists are been published for amphibians, corals, mammals and birds, and help to guide conservation priorities for the most at risk species. Using a complex formula, the Edge program awards a threat score to unusual species that are at risk of extinction.

At the top of the reptile list is the Madagascar big-headed turtle, which has an Edge score higher than any other amphibian, bird or mammal, but is unfortunately still hunted for food and global trade.

Mary River turtle Related: The strange tale of the Mary River turtle

Things you may not know about the Mary River turtle

The Mary River turtle is one of our most punk-rock species and has a number of unusual features that make it evolutionarily unique. Here’s everything you need to know.

  • Mary River turtles begin life as a tiny hatching of approximately three to four centimetres in size, but grow to be one of Australia’s largest freshwater turtle species.
  • A Mary River turtle breathes through its cloaca, a part of their genitals, which allows them to stay under water for up to three days.
  • Due to their docile nature, thousands of tiny hatchings were sold old as ‘penny turtles’, throughout the 1960s and ’70s. It was not known that they belonged to a species found in only one river in the world.
  • Often seen sporting a green mohawk, the Mary River turtle supports local algae life, with strands of green algae seen growing on their heads, shell, and various other body parts.
  • Mary River turtles take a long time to reach sexual maturity, not breeding before they reach 25 years of age.
  • The Mary River turtle has a unique tail that makes it the subject of great interest across both Australia and the world.
  • This spectacular tail contains a number of bones that form a hook, and features a deep cavity lined with gill-like structures that extract oxygen from water.
  • Using its unique abilities, these turtles can remain submerged for up to three days at a time and have been given the appropriate title of ‘bum-breathers’.