Feral pigs a threat to freshwater ecosystems

THE feral pig – an environmental scourge - will be better managed following new research into its impact on freshwater areas.

Biosecurity Queensland senior zoologist Jim Mitchell said anybody who travelled through the outback of far north Queensland could see the environmental impact of feral pigs.

“Around almost every water body, be it a creek or lagoon, you will see large areas of ground dug up by feral pigs in search for food,” Dr Mitchell said.

“We commonly see groups of 20 to 100 pigs around water bodies in Cape York during the dry season and wondered if the repeated diggings had significant long-term impacts.

“A project to analyse the impact of feral pigs on water bodies has confirmed they are environmental vandals.

“The study was conducted at Lakefield National Park, a region on Cape York renowned for its vast river systems and spectacular wetlands.
“Our research defined the damage that feral pigs cause to tropical freshwater ecosystems.

“As expected, feral pigs clearly had a dramatic impact on the ecology of the unprotected freshwater lagoons.”
Dr Mitchell said the impacts included major destruction of plant communities, particularly water lilies, which were the pig’s favourite food.
“They dig underwater to forage for plant tubers,” he said.
“The destruction of aquatic plants and the sediment disturbance significantly reduced water clarity.
“Pig diggings caused high turbidity levels, reduced the amount of dissolved oxygen and increased the nutrient loads in the water.
“The data collected in this study will help organisations and land managers make decisions on the best way to manage the environmental damage caused by pigs.”
Dr Mitchell, who led the multi-agency study, will present his findings at the Pest Animal Symposium to be held in Gladstone from August 3 to 5.
“During the research we compared the water quality between lagoons fenced to keep out pigs and lagoons left unfenced,” he said.

http://qcl.farmonline.com.au/