The man was attacked at Point Plomer Beach, north of Port Macquarie, this morning.

A Mid North Coast Local Health District spokesperson said a 39-year-old man was in a stable condition with minor injuries at Kempsey Hospital.

A man is in hospital after he was attacked by a shark at Point Pomer, NSW. (@at.health)

9news.com.au understands the man self-reported to the hospital.

Spokespeople for NSW Ambulance and NSW Police confirmed no emergency services were called.

A shark had been spotted at the beach at 10.08am, according to SharkSmart.

Beaches between Town Breach and Crescent Head have been closed.

Multiple beaches have been closed. (@at.health)

It’s the fourth shark attack in NSW waters in the past 48 hours.

An attack yesterday evening at Manly put a surfer in the hospital in a critical condition.

Earlier that day, an 11-year-old boy had a narrow escape at Dee Why when a shark took a bite out of his board.

Authorities said a shark took an estimated 15-centimetre chunk out of the boy's surfboard at the netted Dee Why Beach, near Dee Why Point, about 11.45am today.A photo of the surfboard shared by the Manly Observer. A photo of the surfboard at Dee Why Beach shared by the Manly Observer. (Manly Observer)

And on Sunday afternoon, a 12-year-old boy was critically injured in the water at Vaucluse.

Swimmers at still-open beaches have been advised to stay away and avoid murky and low-visibility water.

The NSW Department of Primary Industries say bull sharks are known to frequent Sydney Harbour, especially during the year’s warmer months, and can be found in shallow waterways.