A surfer has been discharged from hospital after a shark attack near Broken Head on the NSW north coast.
9NEWS understands the man suffered puncture wounds to his upper thigh, with his board taking the brunt of the impact.
The man was waiting to catch a wave off a beach between Suffolk Park and Broken Head around 7.30am when the shark attacked from below.
Witness Stuart Holland told the TODAY Show he was walking along the beach watching his kids, who had just entered the water, when he noticed people gathering further up the beach.
"There was a group of guys coming in and they were starting to walk back up the beach waving their boards around," he said.
"One of them was definitely limping, had blood running down from the bottom of his wetsuit, quite a lot of blood.
"They were waving their boards trying to indicate to other surfers. At that point I started to panic about my kids.
"[They were] paddling out to where the main pack was, which was thinning down by that point because obviously they'd heard, but my kids hadn't."
His daughter Belinda Holland said she was surfing when she saw "his board went flying into the air". She said her dad called her back in to the beach.
"He got a massive chunk out of his leg and his side and it was a lot of blood."
Witness Geoffrey Knapp said he and a friend were surfing near a group of dolphins when he saw the man leave the water in a hurry.
The man had seen the shark's tail as it bit him, he said.
"He got the impression the shark was trying to knock him off his surfboard and try and roll him over," he said.
He gave the man first aid on the beach.
"Once we had a good look at it we could see it was incredibly close, but only a superficial wound," Mr Knapp told ABC Radio.
The man was taken to Byron Bay Hospital by a friend.
All beaches across Byron Bay including the patrolled Main Beach will remain closed for at least the next 24 hours. A decision on when to reopen the beaches will be made tomorrow.
The species of the shark involved is not known.
The matter has been referred to the NSW Department of Primary Industries for Investigation.
On Sunday, the department detected a tagged great white off Main Beach at Evans Head.
The latest attack is the 13th in the area since January 2015, including the fatal mauling of Japanese surfer Tadashi Nakahara.
The latest attack comes a day after anti-shark net protesters campaigned at a beach in nearby Ballina.