Ideas for river flow
A NEW project tracking black bream in the Swan and Canning rivers is not only giving researchers an insight into the species but also the health of the waterways.
Murdoch University student researchers Jake Watsham and Nathan Beerkens’ Swan Fish Track study uses acoustic tags to record the bream, one of the rivers’ most coveted fishing species, through the rivers.
Helping to fund the project, a Recfishwest spokesman said preliminary results had given them some interesting information.
“Dedicated fishers would know there are areas where you are more likely to find fish – they can be found as far downstream as Fremantle and well up into the Swan Valley/ Guildford reaches and beyond,” he said.
“The study has helped prove that black bream no longer utilise deeper pockets of water in the middle/upper reaches of the river where oxygen depletion is prevalent.
“Complex environmental reasons are to blame for this, such as a drying climate limiting freshwater flushing of the river, but the accumulation of organic plant matter is also a cause, resulting from fertiliser nutrient loading leading to algae growth, which dies, sinks, decays and consumes oxygen in the deeper waters which is hard to replenish.”
Mr Watsham said making positive changes in the river needed the combined input of the community, scientists and government.