Greens demand end to NSW shark nets

The NSW Greens have called on the government to stop using shark nets as authorities prepare to deploy more than 50 of them.

As the NSW government prepares to deploy shark nets, there are calls to scrap the practice. (AAP)

A leading animals rights group says a decision by the NSW government to continue deploying shark nets "flies in the face of science".

More than 50 shark nets were re-deployed between Newcastle, Sydney and Wollongong on Friday as winter ended.

Humane Society International spokeswoman Nicola Beynon said the government had shunned science in its decision to roll out the nets for another season.

"Non-lethal technology is clearly the future of bather protection and the NSW government is falling behind with its archaic, out-of-date culling methods," Ms Beynon said.

Greens MP Justin Field says the nets are simply a placebo.

"Shark nets may make ocean-goers feel better but the evidence shows they are not effective against target sharks and don't make swimmers or surfers significantly safer," Mr Field said in a statement.

However, there has only been one fatal attack on a netted beach since nets were introduced between Newcastle and Wollongong in the 1930s.

An annual report into shark nets found 373 animals were caught in the nets with more than half of them dying.

Less than 20 per cent of animals caught in the meshing were target sharks.

A spokeswoman for primary industries minister Niall Blair, however, said public safety was the government's number one priority.

"We aim to minimise the risk to swimmers and surfers from shark attacks and the amount of by-catch caught," the spokeswoman said.

The shark nets are fitted with 'dolphin pingers' and 'whale alarms' to deter the sea mammals from becoming stuck in the netting.

"Every available technology is implemented to reduce the impact on threatened species."

Shark nets are deployed along the NSW coast between September and April each year.