Wheat

Surveillance is vital to effective management of cabomba

Thursday 4 November, 2010
The Goulburn Broken Catchment Management Authority (CMA) is seeking community support to target the water-based Weed of National Significance (WONS) cabomba, particularly in the Broken River, Broken Creek and wetlands/billabongs downstream of Casey’s Weir.

The Goulburn Broken Catchment Management Authority (CMA) is seeking community support to target the water-based Weed of National Significance (WONS) cabomba, particularly in the Broken River, Broken Creek and wetlands/billabongs downstream of Casey’s Weir.

A Weed of National Significance, camboma is regarded as one of the worst weeds in Australia because of its invasiveness, potential to spread and economic and environmental impacts. Cabomba is a perennial aquatic weed with feathery leaves that grows quickly and produces vast amounts of submerged plant material. 

Wayne Tennant, Manager Strategic River Health from the Goulburn Broken CMA highlighted “The recent flood event in the Broken River is likely to have dislodged some of the cabomba plant material from Lake Benalla and moved it downstream.   The Goulburn Broken CMA is calling for the community to assist in identifying the weed in either the Broken River or Broken Creek.”

The weed is distinguished by floating leaves and submerged finely divided fan-shaped leaves (see photo).

“Cabomba has been known to be present in Lake Benalla for a number of years.  However, recently some satellite infestations have been located and mapped by the Goulburn Broken CMA between Benalla and Casey’s Weir.  There is concern that the weed has potential to spread further downstream and impact on the environmental and social value of the lower catchment” said Mr Tennant.

Community support is critical to assist the Authority to identify new infestations. 

Researchers from the Department of Primary Industries have noted positive results in the lake during recent monitoring. The amount of plant material has reduced significantly since a survey undertaken in March 2010.  Cabomba cover is now very low with 60 of the 77 sites (78%) monitored having no cabomba. Whereas previously, in November 2009, only 34% of sites had no cabomba.

The Goulburn Broken CMA will continue to work in partnership with the Benalla Rural City, Goulburn Murray Water and the Department of Primary Industries to undertake weed control trials within Lake Benalla and surrounds over the coming months.

For more information on cabomba as a Weed of National Significance please see www.weeds.gov.au.

To report a sighting of cabomba, please contact the Goulburn Broken CMA on 03 5820 1100 or via email at reception@gbcma.vic.gov.au.