Research reveals estuary threats

Jul 10, 2013
Research reveals estuary threats

Two new studies have shed light on the health of Busselton's waterways.

Researchers from Murdoch University spent time in the iconic Vasse-Wonnerup estuary, surveying introduced and measuring nutrient levels in the sediment.

The introduced fish study and removal program, funded through the Caring For Our Country program, found that introduced fish species were thriving.

"In the estuary, we found 29 species of , along with two introduced freshwater species," said Dr James Tweedley, of Murdoch University.

"Sadly, we found the highly invasive Eastern Gambusia in the estuary and in all four tributary rivers too."

The study also found that goldfish, which are not native to the area, seasonally invade the estuary following winter rains.

"These goldfish are highly mobile and seem to be able to tolerate saltier water," Dr Tweedley said.

"The big concern is that this ability could see goldfish using the estuary as a 'bridge' to colonise other rivers."

To track the goldfish, researchers used the same used to track Great White Sharks off the WA coast. The information gathered will assist future efforts to eradicate the species from the Vasse River and estuary.

The second study, funded by the South West Catchments Council, found that the levels of nutrients in the estuary are a cause for concern.

"The sediment we analysed from the bottom of the estuary was high in nutrients. But sediment collected from the water itself had up to 16 times more nitrogen and phosphorus," Dr Tweedley said.

"If these high levels of nutrients continue, it could result in a collapse of the meadows in areas of the estuary, with flow on effects to the rest of the ecosystem."

Explore further: Elk nose into Grand Canyon water stations

add to favorites email to friend print save as pdf

Related Stories

Researchers name new fish species

Apr 16, 2013

(Phys.org) —Researchers from Murdoch University's Freshwater Fish Group & Fish Health Unit and South Australian Museum have officially named Australia's newest freshwater fish: the Little Pygmy Perch (Nannoperca ...

Recommended for you

Alaska refuge proposes killing invasive caribou

3 hours ago

Federal wildlife officials are considering deadly measures to keep an Alaska big game animal introduced more than 50 years ago to a remote island in the Aleutians from expanding its range.

Five ways to stop the world's wildlife vanishing

11 hours ago

Full marks to colleagues at the World Wildlife Fund and the Zoological Society of London for the Living Planet Report 2014 and its headline message which one hopes ought to shock the world out of its com ...

User comments : 0