News

Scientists listen in on groper

In South Australia, marine scientists are using acoustic transmitters and receivers to investigate the habits and home range of the iconic western blue groper.

A team from the Department for Environment and Heritage (DEH) has installed 10 receivers, or “listening stations”, on a 3.5 kilometre stretch of the sea floor off the north-western tip of Kangaroo Island.
Since April this year, when 15 local western blue gropers were fitted with internal transmitters, the listening stations have detected the fish almost 700,000 times.

DEH marine ecologist Dr Simon Bryars said the information already collected had revealed some new details about the life and habits of the spectacular species.

“The high number of detections we’ve collected confirms the fish are very site-specific and spend much of the daylight hours in a relatively small area,” he said.

“We’ve also noticed the fish seem to clock on in the morning and clock off at night, so they are probably heading off to sleep in places where the transmitters can’t detect them, like caves or rocky crevices.”
Some of the fish have also been fitted with pressure sensors, which allow the scientists to detect the depth the fish swim to.

“We’ve found they don’t go deeper than about 18 metres at this particular location, and while they will head out to sandy bottom areas they prefer to stay near the rocky reefs, which are essentially their home base,” Dr Bryars said.

inline_471_https://yaffa-cdn.s3.amazonaws.com/fishing/images/dmImage/SourceImage/Simon Bryars releasing blue groper ms.jpg
Dr Simon Bryars with a blue groper prior to release.

In South Australian waters the western blue groper is among several species of conservation concern.

“The western blue groper used to be common on the southern coasts of the Fleurieu and Yorke Peninsulas, but adults are now much less common in those areas than they were in the 1960s,” Dr Bryars said.

“They still occur in good numbers off the north-western coast of Kangaroo Island, which allowed us to find reasonable numbers of them in a relatively small area.
“This is some of the first tracking research on a marine bony fish species in South Australia, and the information collected will help inform what future protection measures are needed for the survival of the groper population.”

You need Flash player 8+ and JavaScript enabled to view this video.

var params = { allowScriptAccess: “always”, wmode: “transparent” }; var atts = { id: “myytplayer_1493” }; swfobject.embedSWF(“http://www.youtube.com/v/XZHKhEzjJu4&hl=en_US&fs=1&enablejsapi=1&playerapiid=ytplayer”, “ytapiplayer_1493”, “480”, “385”, “8”, null, null, params, atts);

The research project, which is a collaboration between DEH, the South Australian Research and Development Institute (SARDI), Zoos SA, Adelaide and Flinders Universities, and IMOS (a nation-wide collaborative program designed to observe the oceans around Australia), will continue until April 2010 when the listening stations will be retrieved and the data reviewed and analysed.

For more information go to www.marineparks.sa.gov.au or call 1800 006 120.

What's your reaction?

Related Posts

Load More Posts Loading...No More Posts.