Anthony Byrne, Project Officer, Water Infrastructure Corangamite Catchment Management Authority (CMA): The habit installation project that we’re doing here on the Barwon River is to support native fish communities in this part of the catchment. And through our relationship with Emergency Recovery Victoria, they’ve assisted with the transport and supply of this timber.
[A heavy construction machine picks up a root ball from a pile on the barge and swings around to drop one into the Barwon River, Geelong]
[Following storms and floods in June 2021, Emergency Recovery Victoria collected and processed fallen trees. Leftover root balls and hollow logs, which have no value as millable timber, have instead been put to use as habitat for fish]
The Barwon River is like many rivers in our country, sort of had a long history of modification, and in lots of cases they’ve actively removed snags and timber from the river and that has been the kind of core habitat for our native fish species. So as a result, large parts of the Barwon River are virtually devoid of instream habitat and I guess what we’re trying to do through this program is trying to reintroduce what would’ve been that native timber as habitat for native fish. This is the, I guess, benchmark for great instream habitat. It’s very complex, there’s sort of lots of, I guess surface area so that provides lots of things. So it’s substrate for primary production and all of the sort of instream macro invertebrate life; things that sort of support fisheries and also it’s great habitat for refuge and for sort of seeking shelter along the sort of edge of the river. In 2018 we had extensive bathymetry and instream woody habitat density mapping done and I guess that gave us a really clear of picture of where we could be best making our decisions about placement of timber to get the best connection between these sort of habitat nodes along the river.
[heatmap of instream habitat density with high and low temperature colours displayed on the river. The river infrastructure legend colours display red [barrage) yellow (boat launch) yellow (fishing platform) green (rowing platform) with metres scale down bottom].
[map of observed instream habitat volume with circles representing m3 scale size. Worker with map in his hand pointing at places to put root balls and where they have already been put in the river].
Voiceover from CMA worker: We’ve done that one, did that one this morning and we’re going to go down here now…
Anthony Byrne: We’ve sort of installed some in the region of around 700 tonnes of native timber into this section of the river. It’s about a 5 km section of the river here and we’re seeing good results from our monitoring in terms of improvements in native fish habitat and recruitment, Australian grayling, Australian mudfish and Yarra pygmy perch. So it really looks like a crash and a splash but yeah kind of creating good fish habitat is more than just pushing logs into a river. We’ve got a really neat story here about building a fishery from the ground up from what was, yeah, I guess a section of the river that was in very poor condition. And it’s great to think that we’re making best use of something that would’ve been historically chipped or disposed of elsewhere has a perfect application for a fish habitat projects.
[Emergency Recovery Victoria logo]
[End transcript]
Updated