Cumbungi control trial at Four Springs Lake
Anglers Alliance Tasmania was recently alerted to increasing infestation of cumbungi (bullrush) at Four Springs Lake. These infestations could potentially, over time, inhibit fishing in the shallow margins of the lake if left uncontrolled.
It was determined that two control methods would be trialed for effectiveness. The first method is to slash the cumbungi 150mm under the water during January with follow up treatments 4-6 weeks afterwards.
The second method is using a low toxicity biactive herbicide suitable for use in aquatic and sensitive areas on aquatic weeds.
Anglers Alliance Tasmania approached IFS to assist with conducting the slashing method.
AAT volunteers David Lee and AAT Executive member, John Broomby assisted by Neil Morrow of IFS, used a specially converted brush cutter to slash the largest infestation along the southern shore. This work was completed on Monday 15 January.
IFS will engage a contractor to undertake spraying of the remaining eight, smaller, infestations later in January or early February with all treatments being monitored for effectiveness in controlling this invasive weed. Follow up treatments will be conducted accordingly.