Reports of children and adults throwing rocks at sleeping seals and their pups have sparked a warning from conservationists disgusted at the behaviour.
One incident involved teenagers throwing stones at a sleeping pup in Mount Maunganui in an effort to wake it up, and a 30-something year old man throwing a large rock at a sleeping mother seal and her young pup at Mauao, missing hitting her.
Lisa Rooney said she was horrified to witness what she thought was a photo opportunity becoming something much more sinister. She had been heading along the base of Mauao a few weeks ago when she spotted the seal mother and pup relaxing near the shore facing Matakana Island.
''She just had a pup, a really, really little pup and she was doing the sleeping thing they do in the water with the pup.
''People with kids were watching them and a guy, he was with his girlfriend and his or her parents . . . He went to the rocks, I thought he was just going to get a picture but he grabbed a large rock and threw it right at the seal as she was floating. He missed her by an inch.''
The seal took off in the water with her pup and they were not seen again.
''I was so angry. There were people next to me who were angry too, saying 'is that really necessary?' but no one said anything to him. People were too intimidated to say anything.''
Ms Rooney reported the incident to the Department of Conservation. She said there was no excuse for such behaviour.
''It's not hard to know that you should not throw rocks at animals, especially a grown adult with his parents. They all thought they were hilarious but no one else did.''
Last week, marine enthusiast Nathan Pettigrew found a group of teenagers throwing stones at a seal pup at Mount Maunganui.
''When I hit those kids up I said 'cut it out'. They were sheepish and stopped but when I walked off, I heard them say they were just trying to wake them up.''
Mr Pettigrew said he believed it was ''kids just being kids'' but was disturbed to hear the incident was not a one-off.
''It sucks,'' Mr Pettigrew said.
Seals are wild animals and have sharp teeth with a mouthful of bacteria. It is dangerous to get too close. The Department of Conservation also warned it was important for the wellbeing of seals to keep a safe distance.
Mr Pettigrew said he had noticed people were often clambering down onto rocks around Mauao to get close to seals for photos and narrowly missing injuring pups.
''The problem is the pups blend in so well with the rocks and almost get stood on.''
Department of Conservation biodiversity ranger Karl McCarthy said the reports were disappointing. Seals needed a lot of sleep and it was an offence under the Marine Mammals Protection Act to disturb, harass, harm, injure or kill a seal, he said.
''We get probably on average two to three reports a year about kids throwing stones at seals, things like that,'' Mr McCarthy said.
The department had not had any dead or injured seals with suspicious injuries but seal numbers were increasing in the Bay ''so human-seal encounters are becoming more common''.
''We recommend people keep at least 20m away from the animals.''
Anyone charged under the Marine Mammals Act with harassing, disturbing, injuring or killing a seal faces a maximum penalty of two years' imprisonment or a fine to a maximum of $250,000. If anyone sees a seal being harassed they should call Department of Conservation on the DOC HOTline (0800 DOC HOT).