Breaming with knowledge

July 16, 2013

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Dr Joel Williams holding a 360 mm black bream caught in the Wellstead Estuary.

Research scientists from Murdoch University’s Centre for Fish, Fisheries and Aquatic Ecosystems have launched a three-year study to future-proof Western Australia’s black bream against environmental change.

The project, which was made possible by the Recreational Fishing Initiatives Fund and supported by Recfishwest and the WA Department of Fisheries through a grant to Professor Ian Potter, will involve researchers sampling the Moore Estuary, Swan-Canning River, Murray River, Walpole-Nornalup Inlet, Wilson Inlet, Wellstead Inlet and Culham Inlet to collect biological data on the black bream.

Project coordinator Dr Joel Williams said that over the course of the studies, 4000 fish would be tagged in the Swan-Canning River and the Walpole-Nornalup Inlet to enable researchers to track their movements over time.

“The black bream is an iconic species and very popular with recreational fishers, from die-hard anglers to families, making it a cornerstone of tourism in estuaries throughout the state,” Dr Williams said.

“Previous research has indicated that they may be highly susceptible to the effects of environmental change. My work in the eastern states has shown that black bream travel further upstream than in the past, probably in response to changes in the salinity regime brought about by reductions in freshwater discharge.

“As freshwater discharge has declined markedly in south-western Australian in recent years, it is important to act now to gain an understanding of black bream’s current densities and growth, as well as their length and age at maturity in WA estuaries, so that we can inform protection of the species for future generations.”

Dr Williams said Murdoch’s Centre for Fish, Fisheries and Aquatic Ecosystems had worked on the black bream for many years, so new data being collected could be used to determine how biological characteristics have altered with time and thus changed in response to anthropogenic (man-made) and climatic changes to the environment.

“The biological characteristics of black bream vary quite a lot among estuaries, so we’re hoping our studies will give us a better idea about what factors lead to that variability,” he said.

“We want to ensure that we have a sound understanding of black bream biology and ecology so that people can enjoy fishing for this species for many years to come.”

Dr Williams said his team would be visiting angling associations throughout the state to share findings and look at getting locals involved in tagging.

Comments (One response)

calvin lim July 23, 2013

I am a regular amateur fisherman and I kayak fishing around the Canning River's estuary. In the summer breams (mainly) size from 20 – 28 cm were commonly found to have scale/skin infection, while in the winter the infection are less and the level of infection is basically on healing stage. The number of little breams are also plentiful in the estuary which can caught during the change of tide or moving tide. The fishes condition (visual) during the winter seem to be healthier compare to the ones caught in summer. During the winter Black Breams are common taking refuge in caves around the Blackwell Reach in Bicton.

My suggestion for your project is to make comparison with Silver Bream (tar whine) which are also commonly caught during winter in the canning estuary. I would also which to know why do Tarwhine has black stomach lining while the black bream has silver stomach lining-eventhough they shares common feeding habits.

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