Research reveals estuary threats July 10, 2013 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 fish species 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 native fish, 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 acoustic technology 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 sea grass meadows in areas of the estuary, with flow on effects to the rest of the ecosystem." The results of these studies, and its implications, will be discussed at a free public lecture in Busselton on July 17. For more information about this event, please contact Jen Mitchell from GeoCatch on 9781 0111 or firstname.lastname@example.org. Print This Post Media contact: Candice Barnes Tel: (08) 9360 2474 | Mobile: 0408 201 309 | Email: email@example.com Categories: General, Events, Teaching and Learning, Domestic students, Research, School of Veterinary and Biomedical Sciences Research Tags: busselton, eastern gambusia, geocatch, goldfish, james tweedley, murdoch university, south west catchments council, vasse river, vasse wonnerup estuary Leave a comment Name (required) Mail (will not be published) (required) Website You can use these tags : <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong> We read every comment and will make every effort to approve each new comment within one working day. To ensure speedy posting, please keep your comments relevant to the topic of discussion, free of inappropriate language and in-line with the editorial integrity of this newsroom. If not, your comments may not be published. Thanks for commenting!