The pup, whose mother is named Jade, was photographed in February after being born inland - 60km up the Clutha River. Photo: Supplied/ NZ Sea Lion Trust - Giverny Forbes
Authorities want to find out who shot a baby sea lion then left it to die a slow and painful death.
The young female sea lion was shot in an estuary in the Catlins on Monday. A ranger went to investigate reports of a sea lion in distress, but it had died when they got there.
DOC Murihiku area senior biodiversity ranger Rosalind Cole told Checkpoint they believe the pup was shot on purpose.
DOC appealing for information after sea lion shot in Catlins
The shooting was appalling, she said, and DOC staff would do everything they could to find out who did it and take action against them.
"We're seriously upset that this has happened to this little girl. They're very, very rare, they're considered nationally vulnerable - the same as our kiwi, and it's just an appalling act.
"It appears that someone has shot this sea lion ... and the sea lion has continued to have these injuries, and basically starve and die in a really horrible way.
"Shooting a New Zealand's threatened species is highly illegal ... people need to identify their target and understand their firing zone, so this was not accidental by any means."
The same pup attracted attention earlier this year when she was born about 60km up the Clutha River, near Tuapeka.
Wildlife experts speculated that the pup's mum had swim up the Clutha River before giving birth to her in January, to find a safe spot. Photo: Supplied/ NZ Sea Lion Trust - Giverny Forbes
It was a huge blow for the pakake - a threatened species, with the population only returning to the mainland recently and very few breeding females in the Catlins.
The seal had been shot in the hind end. Its body was being sent to Massey University for an autopsy, but a pellet had already been recovered from it, Cole said.
"The maximum penalty for something like this is two years in jail, or a $250,000 fine.
"We encourage people to contact us please if they do have any [information]."
She struggled to understand why someone would shoot a sea lion.
"It's just going to slow the recovery - we've got less than 10 breeding females in the Catlins area, and so every female is precious. They start breeding at around 4, 5-years-old, so this little girl had a few years to go before she was going to contribute to that population, but we've lost that future potential now, so really sad.
"It's absolutely gutting, and seriously frustrating."
The sea lion pup, known as Jade's pup, in February - not long after it was born. Photo: Supplied/ NZ Sea Lion Trust - Giverny Forbes
Cole said because seals do travel widely throughout their territory, it was not clear where the pup was shot before it was found at the estuary.
Rangers had been checking the other sea lions in the area to see if there had been any other injuries, and while there were no signs of other injuries so far, Cole said because they spent a lot of time at sea, not all of them had been checked yet. Rangers would continue to be on the look out, she said.
She said some people had been uncomfortable about the sea lions' return to the area, as they found them intimidating, but keeping a distance from them was the best thing to do.
"We encourage people to respect our sea lions, they use our coast and share that space with us. Drive carefully along roads, because they'll cross roads ... keeping dogs under control.
"Stay back and just watch their fun curious activities from a distance."
Anyone who wanted to talk to DOC about the event could contact them on 0800 DOC HOT.