Man in his 20s dies after shark attack at Emerald Beach, Coffs Harbour

Coffs Harbour, Australia. Photo / Getty Images

Three beaches have been closed by lifeguards after a man died from "significant" injuries sustained during a shark attack on the NSW north coast.

The man, believed to be in his 20s, was bitten on his arm at Shelly Beach, north of Coffs Harbour, just before 11am on Sunday.

The man had "significant" injuries to his arm, with four ambulance crews and the Westpac Rescue Helicopter, which included a critical care doctor and critical care paramedic, were deployed to assist him with CPR.

The man was pulled from the water but despite the efforts of emergency crews to revive him, he died at the scene.

"It was a devastating for everybody on the beach this morning," NSW Ambulance's Chris Wilson said.

"A number of local surfers and bystanders came to the aid of this man, they were incredibly brave in a very challenging situation.

"The Westpac Rescue Helicopter winched in a critical care medical team onto the beach to continue treatment.

"The patient suffered a critical injury to his arm, but despite the best efforts of bystanders, paramedics and other emergency services, the patient couldn't be revived."

Shelly Beach is located at the northern end of the Look At Me Now Headland at Emerald Beach.

Coffs Harbour Lifeguards posted to their Facebook page on Sunday that the three popular surfing spots were closed.

"Emerald Beach, Shelly Beach and Serenity Bay will be closed to all water activity until further notice," the post read.

"Unfortunately, there has been a fatal shark attack in the area. Our sympathies go out to family and friends.

"Please don't enter the water in the area bounded in the below photo. The Department of Primary Industries (DPI) are monitoring the situation.

"We will update this post should there be any further information or changes to the beach status.

"Do not enter the water between Bare Bluff and Moonee beach."