Innovative Tracking Program Sheds New Light on Bream

An innovative and exciting fish tracking program is shedding new light on the behaviour of Black Bream and highlights the importance of water quality and complex habitats such as rock, reef, snags and vegetated banks.  The Swan Fish Track project aims to identify how Black Bream use different habitats in the Swan and Canning Rivers, particularly the waters around the oxygenation plants in Guildford and Caversham. It involved tagging and tracking 55 Black Bream and following their movements and behaviour throughout these river systems.

Local bream fishers played a key role in the project with competitors at a WA Bream Classic event using their skills to contribute 20 of the total fish for the project including the majority of large fish over 300mm. The fish were surgically implanted with acoustic transmitter tags inside their body cavities. The tags emit signals to a series of 25 receivers located throughout the rivers. As a fish swims past receiver information on the time, depth and acceleration of the fish is transferred and recorded.

From this data Murdoch University Researchers Jake Watsham and Nathan Beerkens were able to analyse the first four months of the bream’s movement and behaviour. Their results were discussed at the Fishers for Fish Habitat Forum last month and gave some interesting insights into the behaviour of Black Bream.

Bream are Capable of Travelling….a lot!
The average distance covered by tagged bream throughout the four months of preliminary data was 33km with one fish covering a whopping distance of 130km and on one instance a fish recorded travelling 11km in less than 15 hours. When not on the move, fish spent most of their time at receivers in Ascot and Caversham. There was also movement of some fish between the Swan and Canning Rivers, confirming these populations are interconnected. Some of the bream’s movements through the rivers were found to be linked to heavy rainfall events. While bream are hardy fish that can handle a high salinity range, the tagged fish favoured areas where salinity ranged between 10-20ppt.

Low Oxygen Limits Habitat Availability for Bream
Historically big Black Bream utilised habitat in the deeper holes of the rivers and shallower flats provided habitat for smaller fish. However recent research has suggested that reduced flow in our rivers and a build-up of nutrients in sediments has created low oxygen conditions in the deeper holes. This has possibly contributed to decreased metabolism and growth rates in Black Bream and concentrated the fish into shallower habitats.
The data from Swan Fish Track has supported this research showing that bream had a preference for shallow habitat and avoided areas with low oxygen. Low oxygen appears to be stopping bream from inhabiting deeper areas, reducing their habitat availability.

Bream Need Habitat
The project showed fish favouring areas with complex habitats i.e snags and reef/rock bars. This suggests that replanting shoreline vegetation and restoring reef and snags would provide a real benefit to the fish in this system. With more than 20km of built-up shoreline there is great potential to improve the fishery by enhancing and restoring this habitat. If you are interested in getting involved in habitat projects that will make your fishing better, get in contact with the Recfishwest Habitat Officer, Michael Tropiano at michael@recfishwest.org.au

The Swan Fish Track project was run as a partnership between Department of Parks and Wildlife and Murdoch University, and The Recreational Fishing Initiatives Fund funded post graduate researchers who are contributing to this project.

The project is ongoing and Recfishwest will continue to reveal more results as they become available. All fish tagged for the project have a yellow spaghetti tag next to their dorsal fin so if you catch a tagged fish please call number on the tag with the location of your capture and the tag I.D.
For more on the importance of healthy waterways and their impact on healthy fisheries, read our article here.

Bream Tagging in the 21st Century

A new tagging project will track the movement of Black Bream in the Swan/Canning estuary and needs the help of recreational fishers.  The ‘SwanTrack’ project involves a collaboration between the Department of Parks and Wildlife and Murdoch University (Centre for Fish and Fisheries Research) and involves setting up an acoustic receiver arrays (or ‘listening stations’) that are attached to yellow buoys (with DPaW written on them) right throughout the Swan and Canning estuary.

The array will allow the tracking of any of the larger species of fish to answer questions about how they use the estuary (e.g. where do they breed? which habitats do they use and when?).  The fish are tracked by placing acoustic transmitters inside each fish that are then detected by the receivers when they pass within a couple of hundred metres.

The tags provide useful information on movement patterns and it have the potential to be used for several species. The first project will focus on Black Bream and financial support for honours students has been provided by Revfishwest.  The project will acoustically track Black Bream (Acanthopagrus butcheri) using the SwanTrack array to determine how their movements and habitat use relate to the water quality conditions in the Swan River, including how those movements specifically respond to operation of the new oxygenation plants.
Information gathered will be of direct use by managers in understanding fish response to the plants and possibly enable refinement of their operation to maximise their efficiency.

The tagged bream will have a yellow spaghetti tag (they may foul up a bit and turn black) with Murdoch Uni, a tag number and a phone number.  Researchers would appreciate anyone who catches a tagged fish contact them with where they caught it, when, and its total length. Contact Stephen Beatty, 9360 2813 or www.freshwaterfishgroup.com if you catch a fish. Make sure you take a photo and let us know.

With the cost involved with the project, they would also like people to release those tagged fish, of which there are 55 in the system. Stay tuned for photos, video’s and results of the study.

We’ll keep you updated on the results of the project.

1000 Taggers and Counting

Local recreational fishers continue to contribute to research on key species through their tagging efforts. The Westag program was launched in 1998-99 and still oversees tagging efforts in WA waters.

This long-running citizen science program aims to improve the understanding of recreational fishing species, improve management of recreational fisheries and help ensure recreational fishing in WA remains healthy.

Since being launched over 1000 taggers have participated in Westag, including 42 in 2014-15.

There have been more than 36,000 fish tagged and over 1300 recaptures in that time.

Key species tagged have been Samson Fish, Barramundi, Mangrove Jack, Dhufish and Sailfish.

This year there has been a surge in Mulloway tagging, with a national initiative called the Mulloway Marathon encouraging recreational fishers to tag more of this species.

There have been more than 2000 Dhufish tagged, with a good recapture rate of almost 10 percent.

Fishers tag fish and record key information such as length, location and condition of the fish, which offers important data when the fish is recaptured.

There have been some fascinating recaptures stories, including two Dhufish tagged consecutively by the same charter operator being caught again on the same day and the 1000km travelled Samson Fish.

If you’d like to get involved with tagging, visit http://info-fish.net/westag/ for more information.