A surfer suffered cuts to his leg after being "bumped" by a shark in a notorious hotspot for the predators in eastern Australia Wednesday.

The 25-year-old managed to make his own way to hospital after the encounter at Sharpes Beach in Ballina -- the scene of several attacks in recent years.

"He has told police that he had been surfing with friends for around two hours when he felt something bump his board before he fell into the water at Sharpes Beach," New South Wales police said.

"Police are working with authorities to determine what species might have bitten the man."

Surf Life Saving NSW said authorities have closed beaches in the area for at least 24 hours following the incident.

The close call comes just weeks after a 17-year-old suffered severe bites to the leg after being attacked by a shark in the same area, some 740 kilometres (460 miles) north of Sydney.

Of the 14 unprovoked shark attacks off the New South Wales coast in 2015, most occurred along a 60-kilometre hotspot from Evans Head to Byron Bay which includes the town of Ballina.

Efforts to contain the marine predators have so far proven difficult, with a shark eco-barrier trial in Ballina area recently scrapped due to rough sea conditions.

Following the attack on the 17-year-old, the state government said it would boost the tagging and relocation of sharks using "smart drumlines" to catch them.

The so-called smart drumlines -- which use baited hooks attached to floating buoys to snare sharks -- are meant to be more friendly to other marine life and are not designed to kill the predators.

Experts say shark attacks are increasing as water sports become more popular and bait fish move closer to shore, but fatalities remain rare.