WA ocean heatwave linked to shark attacks

http://www.abc.net.au/news/2012-12-23/wa-ocean-heatwave-linked-to-shark-attack/4441672

The West Australian Department of Fisheries says it will conduct further research on a marine heatwave that has been linked to a recent spate of fatal shark attacks in Western Australia.

Scientists say the unprecedented heatwave occurred off the WA coast between 2010 and 2011, and could be responsible for declining fish stocks and increased shark activity.

Ocean temperatures rose up to five degrees last summer, and the Department says that has led to pockets of cooler water developing near the coastline.

The Department's research director, Dr Rick Fletcher, says this may be causing sharks to move closer to shore.

"If there is a relatively smaller area of cooler water inshore, then the sharks could be concentrated in that smaller area," he said.

Dr Fletcher says further studies will be carried out to determine the long-term effects of the heatwave on fish stocks and shark activity.

"If we actually understand a little bit more about what conditions are more or less likely to have concentrations of White Sharks or Tiger Sharks, than we can inform the public about what the conditions are likely to be," he said.

"Two years post that initial heatwave, what's happened both to the stocks but also what's happened to the oceanographic conditions, have they returned? Or has that change dissipated over the past two years."

There have been five fatal shark attacks along the WA coast in the past two years, prompting a raft of research aimed at trying to better understand the animals.