A surfer in Northland has survived a great white shark attack but has been left with bite marks and a jagged tooth buried in his surfboard.

The attack took place at Baylys Beach, near Dargaville - believed to be the first recorded attack in the Northland region.

The man, who is aged in his 20s and is from Whangarei, suffered moderate injuries in the incident around 6pm and was flown to Whangarei Hospital for treatment.

Dargaville Volunteer Fire Brigade deputy chief Michael Ross said the victim was bitten in several places by the shark but was "walking and talking".

"It's got him in the hand, the elbow, a little bit on his mouth. He was definitely in pain and there was a bit of blood.

"I've lived here 45 years and I can't remember the last person who's been bitten by a shark out here," Ross said.

Ross and the police said they did not know what type of shark attacked the man.

But Department of Conservation marine scientist and shark expert Clinton Duffy said it was an "unmistakable" great white shark attack - probably a "reasonably-sized" one. He pointed to the spacing between the teeth marks on the surfer's board and said the tooth left wedged in the board was from the lower jaw of a great white.

"The tooth [in the surfboard] is from the lower jaw of a Great White and the bite pattern also shows it ... it's unmistakable."

Duffy said he would need to have a measurement of the tooth to know for sure the shark's size and if it was a juvenile or an adult.

"It's hard to say, but it looks like a reasonably-sized fish."

Even a juvenile great white was big - females matured at 4.5 to 5.2m and about 1800kg and males at 3.6m and 800kg.

Duffy said great whites were common around the Northland coast year round, but most inshore sightings were in summer.

Most people survived great white attacks because the attacks were characterised by a bite and release, he said.

There had been two or three other great white attacks off the Northland coast in recent years, among 113 unprovoked attacks on people by all types of sharks in New Zealand waters since 1840.

The shark "wouldn't even know" it had lost a tooth and a replacement would soon grow in its place, Duffy said.

He had been tracking great whites in the Kaipara Harbour and they tended to move along the coast quite quickly, he said.

"That shark has probably moved on [from Baylys Beach]."

Ross said the beach had been closed by police.

A police spokeswoman said the man was surfing at the time of the attack and received bites to his arm and hand.

"He paddled himself to shore following the attack. A man helped him after the attack by giving him a ride up the beach in his ute."

The man was collected by the rescue helicopter outside a shop on Seaview Rd, which happened to be called Sharkeys Takeaways, she said.

Josie Scott's home overlooks the beach and she can see police talking with surfers at the scene.

The Northland Emergency Services Trust rescue helicopter left the beach just after 7pm, Scott said.

"I've just been watching the police and the helicopter. I can't see any little fins out there."

The scene was calm but no one was in the water.

"All the surfers have been called back in."

The beach is popular with surfers, especially on days like today, when the conditions were "just right".

"It's beautiful day. I saw half a dozen surfers there earlier."

Surfers in the water were told to get out by someone on a jetski, Scott said.

Baylys Beach Holiday Park owner Trish Rolfe said news of the shark attack was "pretty horrific" for the small Northland community of Dargaville. Rolfe said while they had never experienced a shark attack before, they had found seals killed by sharks before, and that seals were migrating through Baylys Beach at the moment. "We've found seals that have come up to the beach to die."

In records dating back to the 1850s, there have been fewer than 50 unprovoked, recorded attacks in New Zealand.

The last fatal shark attack was in Muriwai in 2013.