Re-snagging to restore habitat
Goulburn-Broken Catchment Management Authority has been busy re-snagging the Goulburn River this summer by placing tree branches and trunks in the water to provide its inhabitants with a healthy home.
Re-snagging the Goulburn River began in 2011 and was carried out in the summer months.
About 600 snags have been installed above Nagambie including 250 snags in Tabilk Lagoon and 700 in the Lower Goulburn River between Toolamba and the McCoys Bridge area.
GBCMA riparian and river channel manager Jim Castles said snags were being removed from the river up until the 1970s because people believed extracting them would improve river flows and make it easier for boats to manoeuvre.
‘‘It did a lot of damage to the ecology of the river and had an impact on native fish numbers, and it’s pretty well known now that the snags don’t really have all that much impact on flows,’’ he said.
Mr Castles said when the CMA re-snagged the river they used grey box and yellow box trees and sourced them from roadworks and areas where trees had fallen down because of storms.
‘‘In-stream habitat mapping has been carried out in the Goulburn River by scientists from the Arthur Rylah Institute and this mapping has helped us to identify areas that had a low density of snags,’’ Mr Castles said.
‘‘The mapping also helped us to select areas where resnagging would have the greatest benefit for native fish populations and anglers.’’
Mr Castles said it was unlikely they would ever get snags back in the river at the density they once were, but they were doing a lot of work with nature along the side of the river so trees could naturally fall in and provide water creatures with that inland coral-like atmosphere they needed.
‘‘Native fish monitoring is being carried out annually and will help assess the impact of the resnagging program on native fish populations within the Goulburn River,’’ he said.
— Sionnie Kelly
Restoring ecology: A machine is used to drop a snag into the Goulburn. Pictures: Sionnie Kelly