Fish of Holbrook

Holbrook is in the catchment of Billabong Creek, one of the longest inland creeks in Australia. Since the flooding rains of 2010/11 there have been many reports of seeing species of fish in the Billabong and contributing streams that haven’t been seen for many years.

Click to visit the Fish gallery

During Drought…

The availability of water is not an option for fish, although some Australian species have adaptations to drought that allow them to survive.  For example the River Blackfish can tolerate very low oxygen levels to survive in drying water sources.

However, the presence of deep refuge pools is essential to all species. Sedimentation and de-snagging of our creeks and rivers mean that there are less deep holes that retain water in which fish can survive during these times.

Fish Habitat
Image Credit – © Luke Pearce

Good Fish Habitat
Image Credit – © Luke Pearce

Habitat…Habitat…Habitat…

Fish require places to breed within the stream, and large woody debris is an extremely important resource. Historically, streams have been de-snagged to try and maintain stable flows, create safe recreational areas and reduce point erosion problems.

In reality, these large logs and snags are needed in our streams for fish habitat. Erosion is a natural part of stream changes over time, but many of our local streams have unnatural amounts of sediment moving through them from accelerated erosion and clearing of riparian vegetation. Large logs and snags create turbulence that form the deep pools required by fish and can help move sediment on.

Carbon drives production in stream food chains and material from riparian vegetation is the primary source of that carbon. Vegetation provides habitat for fish food, shade and shelter Streams without vegetation which provides habitat for fish food, shade and shelter are generally poor in fish species and numbers if they have them at all.

To help the native fish community, our local waterways need to be improved. Timber is a low-cost stream stabliser, creates turbulence and provides refuge holes for fish.

Trial resnagging has already taken place at sites in the Wantatgong Creek.

Resnagging – BEFORE
Image Credit – © Kylie Durant

Resnagging – AFTER
Image Credit – © Kylie Durant

More Information…