A Murdoch University fish researcher is looking for volunteers to help him catch and tag Black Bream, King George Whiting and Southern Blue-spotted Flathead to determine their movements in the Walpole and Nornalup Inlets Marine Park.
Daniel Yeoh, a PhD student whose project is supported by the WA Department of Fisheries, wants to better understand how these important recreational species use this estuarine system, and how their movements respond to various environmental factors, including tides and freshwater flows, as well as other stressors like fishing pressure.
“Despite the ecological importance and uniqueness of the Marine Park and its value as a recreational fishery, there is little recent data available on its fish communities or how key fishery species use the system,” said Mr Yeoh.
“We will be tagging fish with small internal acoustic transmitters so that they can be tracked remotely – a technique known as acoustic tracking. This allows us to gather detailed information on the movements of individual tagged fish throughout the Marine Park. We can track fish as they swim between regions of the estuary, and also determine if and when they swim out to sea.”
As well as the internal acoustic transmitter, which is not visible, fish are also tagged with an external yellow tag (approx. 2-3 cm long) so that they are easily identified. These external tags contain a unique identification number (four digit code) and a phone number. If you happen to catch a tagged fish, Mr Yeoh asks that you please record the tag number, length of the fish, where and when it was caught, and call the phone number which will go through to researchers at Murdoch University.
Mr Yeoh explained that the tagging project would help him to determine the locations of greatest importance to these species, such as spawning aggregation sites and nursery areas. It will help identify habitats that are key for sustaining the fishery, how fish movement patterns are likely to respond to future stressors, and thus how management plans may need to be adapted.
“In addition to acoustic tracking, over the next two years I will also be collecting information on the abundance and size composition of all the fish species in the system, and comparing this to historical data collected by Murdoch University researchers 25 years ago to see if they have changed over time,“ he said.
“The goal of this project is to contribute important data allowing managers to better protect this important estuarine ecosystem and its fish stocks, thus ensuring it can continue to be enjoyed by the whole community.”
If you would like to help out with the research, a fish tagging session targeting Black Bream and Flathead will take place on Sunday, November 2, from 8am at Rest Point. A free BBQ lunch will be provided and there will be prize giveaways for anglers.
If you would like to take part or have any questions, please email Daniel Yeoh.