THE ADVERTISER (Adelaide, Australia) 16 February 07 Town fears turtles will die (Cara Jenkin)
Barmera residents fear the future of a rare turtle species will be sacrificed if Lake Bonney is blocked off from the River Murray.
Each year, 29 gigalitres of water evaporates from the 1700 ha lake, which is topped up by flows from the river. To reduce the loss, the State Government is considering installing a temporary weir.
Residents have already raised fears the weir would damage the town's lake-based economy and, together with environmentalists, are concerned about wildlife, particularly a unique population of broadshell turtles.
Action group spokeswoman Robyn O'Dea said hundreds of thousands of native fish, as well as the turtles, would be dead by winter if the weir was built and the lack of fresh water raised salinity to lethal levels. "Once it's in, there's no stopping the Government from delaying its removal for the sake of irrigation or Adelaide's drinking water," she said.
Turtle expert John Bannear said no one knew exactly how the turtles, native to eastern parts of the river system, came to live in the lake, but common belief was that they migrated to SA in the 1956 flood.
He said turtles sensed changes in water levels, would walk across land in search of a more stable area, and then be picked off by foxes and crows.
"The broadshell turtle is endangered in Victoria and it is like the sea turtle - it takes almost 1000 eggs to hatch to have one survive," he said.
"If (Water Security Minister) Karlene Maywald and (Premier) Mike Rann treated their pets like they intend to treat marine life in the river, they would deserve a jail sentence."
Ms Maywald said the weir would reduce the lake's surface area by 5 per cent in 12 months and the shoreline would recede about 70m.
The amount of water saved would be double the amount already recovered by blocking 27 regulated wetlands on the river. The State Government has not set a deadline for a decision.
Town fears turtles will die