A person at the beach said lifeguards blew their whistles and recommended people leave the water around 3.30pm.
It comes in the same week a young woman suffered serious injuries in a shark attack in the South Island.
The shark was spotted at the end of the bay close to Ōkura.
About 50 to 80 people were at the beach.
"The lifeguard said they can’t stop people going in, but they recommended you hop out of the water - so everyone’s hopped out of the water," she said.
She said by 3.45pm, a handful of brave people had already returned to the water.
At the other end of the country, earlier this week a woman in Southland was taken to intensive care after undergoing surgery and following a shark attack.
The 21-year-old suffered a significant leg wound in a late-night shark attack while wading in knee-deep water in the early hours of the morning.
Southland Police said the woman was walking through the water in an estuary near the Riverton rugby grounds when she was bitten by the shark.
The mother of a woman attacked by a shark in Southland says the family often spend time in the estuary where she was bitten and says her daughter was simply "unlucky".
Her mother told the Herald the incident would "have a deep impact" on her daughter, but said she was doing well.
The mother said being in the water at that time of the morning, around 2am, isn’t "uncommon" for the family.
"My husband and I are recreational divers and enjoy fishing and floundering, my daughter didn’t think twice about being there.
"That could have been any of us who flounder in that area however my daughter was just unlucky," she said.
"We certainly do not want this random and unfortunate accident to have a negative impact on such a beautiful town or our stunning beaches.
"We just want people to err on the side of caution when entering our waters and to be vigilant about their surroundings.
"We are in the shark’s environment and should be respectful and mindful of that."
Speaking to the Herald in 2022, New Zealand Marine Studies Centre educator Rob Lewis said that in southern New Zealand, sevengill sharks often moved closer to shore in the summer.
They were "very curious animals" and fast movements and splashing could trigger them to investigate.
"Of course, their way of investigating is by biting things," Lewis said.
If approached by a sevengill shark, the most important thing to do was to keep eye contact with it, he said.
"After which, you should try, as calmly as possible, to exit the water."
Water Safety New Zealand has resources and advice for all water-going holidaymakers.
