Acoustic curtain tracks marine life at Montague

LOCALS may not know it but there is a “curtain” of nine sound-detecting underwater receivers stretching between Montague Island and the mainland.

These receivers pick up and record signals from a variety of acoustic tags placed on fish and marine mammals by various scientists and research programs.

The data collected as these tagged fish swim past is freely accessible by the general public and allows marine researchers to track the animals they have tagged as they swim past Montague Island, as well as other acoustic curtain locations.

This knowledge helps improve our understanding of our oceans for conservation and commercial purposes and also could assist in understanding mysteries such as whether sharks are increasingly hugging the coasts.

The receivers are installed on the seafloor and monitored by the team at Australian Animal Tracking and Monitoring System (AATAMS), who are funded by IMOS – Integrated Marine Observation System.

Since 2006, IMOS has been routinely operating a wide range of observing equipment throughout Australia’s coastal and open oceans, making all of its data accessible to the marine and climate science community, other stakeholders and users, and international collaborators.

James van den Broek, Andre Steckenreuter and Phil McDowall from the Sydney Institute of Marine Science (SIMS) are tasked with regularly servicing and downloading the data from the acoustic receivers.

“A big part of the project is to provide this scientific data to the public by uploading the data to a national database for the general public to access and have a look at what is being detected,” he said.

Anyone interested in accessing the data, simply needs to apply for an access code.

The Montague Island acoustic curtain is one of three managed by AATAMS in NSW, the other two being between Coffs Harbour and the Solitary Islands and also a line out from the famous Bondi beach in Sydney.

There are other acoustic curtains around Australia, including at Maria Island off Tasmania where there was a recent great white shark attack, as well as off the Great Barrier Reef and Western Australia.

Van den Broek said the Narooma acoustic fence starts with an underwater buoy located in water about 50m deep just east of the island and then extends west of the island with receivers around every 800 metres all the way to the shallow water on the mainland south of town.

Some of the receivers in the more shallow locations are simply attached to star pickets hammered into rocky bottom, while in deeper water they are more sophisticated, combining a transceiver with an acoustic release allowing researchers to remotely retrieve deployed receivers from the surface.

The IMOS Australian Animal Tracking and Monitoring System (AATAMS) team earlier this year undertook a successful service of the Narooma line, which included the deployment of six of these new VEMCO VR2-AR receivers.

The acoustic tags that send out the signals vary in size and can be as small as a Tic Tac that could be placed in a small fish such as a flathead, all the way to larger, longer-lasting devices that can be placed in larger fish such as bluefin tuna and sharks.

Researchers are restricted from placing tags in certain marine mammals such as whales and dolphins as they could interfere with their navigation and communication.

What is IMOS?

IMOS is one of the national research infrastructure capabilities currently supported under the Australian Government’s National Collaborative Research Infrastructure Strategy (NCRIS).  It has been awarded $130M of Australian Government funding over nine years (2006-15), with matching co-investment of $170M.

IMOS operates as a multi-institutional collaboration.  IMOS is led by the University of Tasmania in partnership with the CSIRO, Australian Institute of Marine Science, Bureau of Meteorology, Australian Antarctic Division, Geoscience Australia, Sydney Institute of Marine Science (encompassing the University of New South Wales, The University of Sydney, Macquarie University and University of Technology Sydney), University of Western Australia, Curtin University, James Cook University and the South Australian Research and Development Institute. 

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