A man has died following a shark attack in Australia despite the efforts of "incredibly brave" surfers and bystanders who came to his aid, authorities said Sunday.

The man, believed to be in his 20s, was mauled by the shark at Emerald Beach near Coffs Harbour, about six hours north of Sydney, according to paramedics.

Emergency crews, including a helicopter medical team, rushed to the scene just before 11:00am local time on Sunday after receiving calls for help.

Chris Wilson, a New South Wales Ambulance inspector, said paramedics arrived to find local surfers and bystanders attempting to save the man, saying the group was "incredibly brave in a very challenging situation".

"It was devastating for everybody on the beach this morning," he said.

"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."

The Coffs Harbour Lifeguards service said the beach and surrounding waters were closed to swimmers and surfers due to the incident.

"Our sympathies go out to family and friends. Please don't enter the water in the area," a Facebook post said.

It was the second fatal shark attack recorded in Australian waters this year, according to the Taronga Conservation Society Australia.

There were 26 maulings in 2020, eight of them fatal, data from the government agency shows.