Six satellite-linked drifters will be deployed between Cape Leeuwin and Cape Naturaliste this week, to help Department of Fisheries WA researchers learn more about the Capes Current.

Supervising Scientist, Dr Dan Gaughan said little was known about the day-to-day behaviour of the important Capes Current, but it was vital in carrying and dispersing eggs and larvae of summer spawning fish, such as the popular Western Australian dhufish.

“There is a need to understand where the eggs and larvae of shelf species may be transported to, if anywhere, after spawning,” Dr Gaughan said.

“The Capes Current is a northbound ocean current that flows up the continental shelf of south west Australia every year around summer. It is named after Capes Leeuwin and Naturaliste, where it is thought to originate.

“We know it is driven by the persistent and seasonal southerly winds, but the drifters we will be dropping into the current will give us a better idea of its speed, the direction of flow and sea surface temperatures, on an hourly basis.

“This data will help improve our oceanographic modelling for the region and provide a better understanding of both along-shelf and cross-shelf water movements and their potential impacts on dispersal of eggs and larvae.”

Dr Gaughan said the new satellite drifters were being deployed under a project funded by the Western Australian Marine Science Institution and the drifters could be tracked online by researchers and also interested members of the public at http://sharkmonitor.com/.

“These drifters are designed to follow surface currents by having a six-metre long drogue (think of it as a sock with holes), suspended below the surface. It is tethered to a surface unit that, every hour, will transmit sea temperatures and position via satellite.”

Additional research projects will also be carried out from the RV (Research Vessel) Naturaliste, as it journeys through South West waters this month.

“It will be a multi-faceted trip, as far as dhufish research is concerned,” said Dr Gaughan.

“A researcher from the Curtin University will be aboard with his acoustic logger, listening for dhufish noises as part of a Fisheries Research Development Corporation-funded project.

“Department of Fisheries researchers will also be continuing work on the identification of critical habitats for juvenile dhufish, which is part of a Natural Resource

 

 

Department of Fisheries media release, Tuesday, 8 February 2011