A man has been left with a 20-centimetre gash on his leg after being attacked by a juvenile white pointer shark on the NSW far north coast.

Key points: The man took himself to hospital with non-life threatening injuries

The man took himself to hospital with non-life threatening injuries He fought the shark off with his surfboard

He fought the shark off with his surfboard All beaches in the area are closed for 24 hours as patrols take place

The 43-year-old local was surfing with two friends at Ballina's Shelly Beach early this morning.

He told police he was bumped off his board before 7:00am and then saw a five-foot shark circling and coming back towards him.

The shark was later identified as a 2.6m white shark.

Police Inspector Bill McKenna said the man struck out at the shark with his board.

"They've managed to paddle into shore and he's realised he had a large laceration on his left calf," he said.

"(He was) very lucky in the circumstances."

The man took himself to Ballina Hospital and has since been transferred to Lismore Base Hospital.

The Surf Lifesaving duty officer in the region, Jimmy Keogh, said beaches in the area would be closed for 24 hours, at the request of police.

"You are looking at all the beaches from South Ballina beach through to Lennox Head, so we are just advising people to follow directions by lifeguards and lifesavers and police on the beach," he said.

Bite marks were visible in the man's surf board. ( ABC News: Elloise Farrow Smith )

Mr Keogh said the man's injuries were not life threatening.

The incident prompted increased surveillance in the area, including the use of a drone.

"Conditions are going to deteriorate today in the water," Mr Keogh said.

"So we just have to be careful about the welfare of our members as well, but we are keeping a close eye on the area at the moment."

Ballina Mayor David Wright said SMART drum lines were deployed.

"Everything that could have been done is being done," he said.

Shelly Beach and surrounding beaches have been closed following the shark attack. ( ABC News: Bruce Mackenzie )

Cr Wright said the shark was estimated to be a metre and a half long, but there was no information about what type it was.

"It was a smaller shark, but any bite is a dreadful thing to happen," he said.

"I just want people to be reassured that once the 24 hours is over there will be senior surf lifesaving people and even more protection than we had before."

Cr Wright said the main concern for the victim was ensuring the wound was properly cleaned out and there was no damage to nerve endings.

The attack was the latest in a series of incidents on Australia's east coast.

A police officer and a drone operator help keep a lookout for the shark. ( ABC News: Bruce Mackenzie )

Melbourne medical researcher Daniel Christidis died in north Queensland on Monday night after being attacked by a shark in the Whitsundays.

It was the third shark attack at Cid Harbour in six weeks and was described by paramedics as "the worst one yet".

Dr Christidis was attacked while swimming in the same waters where Justine Barwick was bitten on the upper leg on September 19.

Less than a day after Ms Barwick's attack, a 12-year-old Melbourne girl lost a significant amount of blood when a shark mauled her thigh.

Following the attacks, Queensland Fisheries Minister Mark Furner said no-one should swim in Cid Harbour.

"We can't be clearer — don't swim in Cid Harbour," he said.