BASS Strait water is a bit anti-social when it leaves its home, refusing to mix with other water and going on long journeys alone.
CSIRO scientists using a $200,000 underwater glider to track changes in the east Australian current found the unusual behaviour of water by chance. What looked like corrupted data turned out to be a chance finding that will add to the understanding of Tasmanian waters.
Oceanographer Ken Ridgway said the Bass Strait water stayed in balloons about 200m high and 40km across as it joined the east Australia current in the Tasman Sea. "At depth, we find it's both saltier and warmer than water around it," Mr Ridgway said. "That's how we know it's Bass Strait water. "It retains that signature and doesn't mix with the water around."
The balloons then merge with huge spiralling areas of water or eddies and head south. "Some of these eddies can be very long-lived and can travel around southern Tasmania and into the Indian Ocean near Western Australia," he said. Further research is needed to discover if the temperature of the current is exploited by fish or other marine animals. "It's like a needle in a haystack but, with the glider, we can focus on the centre of the eddy and get a lot of measurements."