A video of a body boarder wildly swinging his board several times at a sea lion shows the "ignorance" people have towards the threatened species, the Department of Conservation (DoC) says.
The man was filmed interacting with the animal at St Clair Beach on Monday morning as he tried to go into the water.
As the sea lion emerges from the water and advances on him, the man begins backing away and holds his board up as though he's preparing to hit the animal with it in self-defence. He swipes twice at the sea lion's head, only narrowly missing hitting it both times.
Jim Fyfe, a biodiversity ranger at DoC, told the Otago Daily Times people who don't normally visit the coast are having their first experience with the wildlife - and often getting it wrong.
He says the sea lion would've interpreted the swings at its head as playing, which could've been bad news for the body boarder.
"It's just ignorance," Fyfe told the outlet.
If people find a sea lion in the water or on the sand, he says they need to wait or move to another part of the beach. But if confronted by a sea lion, the best option is to "freeze" and use something like a surfboard or bag as a wall if it's available. If the person wants to leave the area, it's better to walk rather than run.
"Get right out of the situation - five metres and then stopping is just a game," Fyfe says.
"They're a big animal, they've got sharp teeth. [When] you're confronted with them, you get all the fight-flight emotions coming into play and so you can do silly things."
Sea lions aren't there "to bite you or eat you", they're instead being playful and people can give the wrong signals by being scared, he adds.
New Zealand sea lions are one of the rarest sea lion species in the world and are only found in Aotearoa.
Most of the 12,000 population is at the Auckland and Campbell subantarctic islands, DoC says, and there are emerging breeding locations in Stewart Island, Otago, and Southland.