Using know-how to save a species
ONE of the few south-north flowing rivers along the east coast, the Mary River is home to endangered and iconic species.
A workshop, attended by about 30 people, organised by Gympie Landcare and addressed by turtle expert Marilyn Connell, from Tiaro Landcare, dealt with the turtles of the Mary, with particular emphasis on the unique mary river turtle.
Ms Connell, who said this turtle was only scientifically identified in 1994, has become a world authority on this and other river turtles.
"The Mary River has six endemic turtle species," she said. "This is only bettered by a river in the Gulf area."
Ms Connell said before we could be definite about what turtle species we actually had in the river, we had to have positive identification.
In broad terms, the Mary's turtles were split into generalists and river specialists.
"The fact that the river specialists such as the mary river turtle and the snapping turtle are rarely found out of the main river can be an initial guide to ID," Ms Connell said. "The saw-shelled turtle prefers fast-running rocky areas of a stream and once again locality can be a bit of help with ID."
The main identification method was by looking at differences in the shell. Quite often the only indication that a particular species was present was finding a hollow shell.
"A species can be ID from aspects of the shell," Ms Connell said.
"Size is not the best guide as this can vary with age."
Some physical features used in turtle identification included the under shell and whether there was a V or U-shaped notch at the rear for the tail, also the arrangement of shields at the front of the shell.
The top shell had scutes or sections that made up the shell, with two species having a single or nuchal scute at the top front.
Head appearance could also help, with some having a head shield that extended down the side of the head, a large tympanum (ear cover), large under jaw barbells and different sized tubercles.
These were bumps that appeared all over the upper surface of the neck behind the head.
Tiaro Landcare had available a key that could be used to identify turtles by giving a series of choices to select until there was only one left.
Because the Mary River turtle lived at least to 80 years, recovery could be a long-term process as it had been estimated the number of breeding females (20 years of age and over) dropped by more than 90% in the past five decades.