A swim at the beach ended in tragedy yesterday, when a woman was killed by a shark in the Bay of Plenty.

Emergency services rushed to Waihi Beach just after 5pm yesterday, including two ambulances, a first response unit and a TECT Rescue Helicopter, which was stood down on arrival when it was determined that the woman had died.

Tadhg Stopford, of the company Tiger Drops, said he saw a helicopter land at the beach and people attempting CPR on the woman for several minutes.

"Vigorous CPR was being applied, and a troop of responders encircled the victim."

The woman died at the scene a short time later and the incident will be referred to the Coroner. Photo / Tadhg Stopford

He said after work on the victim had ceased, a man walked into the ocean.

"The man roused himself and marched 100m into the sea," Stopford said.

"His entry into the sea was a challenge, I guess, to the shark who had stolen the life of his loved one. He defiantly waded deep into the sea, and stayed there for several minutes.

"With my children around me, I felt his loss."

Western Bay of Plenty Katikati-Waihi Beach ward councillor Anne Henry said it was an "absolute tragedy". Fellow ward councillor James Denyer said he'd lived in the area for more than a decade but this was the first fatal attack he'd heard of in the local waters.

"Tend to think it happens in Australia," he said.

Western Bay of Plenty Mayor Garry Webber, who has also lived in the area a long time, said he couldn't remember a shark attack in the region.

"When these things happen your thoughts immediately go to the family," Webber said.

"And particularly the responders, the coastguard, the ambulance, air rescue helicopter, who had to attend. You really feel for them."

Surf Life Saving New Zealand national search and rescue manager Allan Mundy said a key concern was the wellbeing of the lifeguards involved.

"Our team will be meeting with peer support team and we'll be going through the events of the day and looking at any support we can provide out lifeguards emotionally, moving forward from here."

Waihī Beach is a holiday destination for Kiwis, Webber said, with its population swelling at this time of year from about 4000 people up to about 20,000.

Shark scientist Riley Elliott said without all the facts, it's hard to speculate what species of shark attacked the woman.

Shark scientist Riley Elliott says it's hard to speculate what species of shark attacked the woman. Photo / Supplied

However, there has been evidence of juvenile and immature Great Whites in the area as of last summer.

He added that Bronze Whaler sharks were more common in the area than Great Whites, but hadn't had adverse interaction with a human in a very long time.

He said shark attacks in general, and especially fatal, are rare.

The last deadly shark attack in the Bay of Plenty, according to website Shark Attack Data, was in 1875, in the 145 years.

"Shark attacks are incredibly rare and if you see one, remain calm, alert people around you, and calmly vacate the water."

Elliott said his thoughts were with the family and friends of the woman after the "tragic" incident.

New Zealand shark attacks

Just over a year ago a 3.5m great white shark was spotted by people on a boat near Waihī Beach, while a 2m-long shark washed up dead at the same beach in 2019.

Waihī Beach was also closed down in January 2014 after lifeguards and swimmers spotted a small shark near the shoreline.

In February 2013, father-of-one 46-year-old Adam Strange was killed after he was attacked by a shark while swimming at Auckland's Muriwai Beach.

Up to 2014, there had been 12 reported fatal shark attacks in New Zealand.

That includes one in 1966 in Auckland's Manukau Harbour, plus at Te Kaha (1976), Napier (1896), Oakura (1966), Wellington (1852), Kumara (1896), Moeraki (1907 and 1967), St Clair (1964 and 1967) and Aramoana (1968).

The 1964 attack at St Clair, Dunedin, took the life of lifeguard Leslie Jordan, 19.

Tragedy struck Taranaki in 1966 when 15-year-old New Plymouth schoolgirl Rae Marion Keightley was mauled while bodysurfing off Oakura Beach.

Keightley had her left leg bitten before surfboard rider Anthony Johns brought her to shore.

Last February a 60-year-old man had a lucky escape while out surfing at Pauanui Beach, on the Coromandel.

The man was bitten on the arm, before the shark latched onto his surfboard.

The shark finally disengaged after being punched twice.