The Department of Conservation yesterday confirmed Jade, the mother sea lion of a pup that was shot and killed in the Catlins last month, was also found killed by someone using a firearm.
She was found on Tuesday evening, about 100m from where her pup was found dead.
It is believed she washed up there during the recent flooding.
NZ Sea Lion Trust spokeswoman Jordana Whyte said "disappointing" was not a strong enough word to describe the second killing.
"It was bad enough to have lost her pup in that way, and then to lose both the pup and the adult breeding female — it’s so senseless and pointless and none of us understand it at all."
The trust had worked hard to educate people about New Zealand sea lions (pakake) and to show that everyone could live respectfully alongside them.
The person responsible for Jade’s death clearly did not understand sea lion behaviour, and she could not accept it was a possibility anyone could have feared for their life or felt threatened in this case, Ms Whyte said.
"This was done intentionally and with malice.
"The kind of person who can for no reason cause grievous bodily harm to an animal and death is certainly a person I don’t want to encounter in my life.
"I don’t know what else that person is capable of. It’s just completely avoidable."
Jade was well-known, well-loved and had been "really important" to the sea lion population given her breeding history, Ms Whyte said.
She was born under a crib at Kākā Point in 2016 and was named after the late son of the crib owners.
Ms Whyte said she did not believe the individual responsible was representative of the community in the area, and she expected they would be outraged.
"The optics of somebody gunning down a mother and daughter sea lion pair, it’s not going to sit right with people."
The extent of Jade’s and her pup’s injuries, along with the trust’s understanding of what both animals went through at the time of their deaths, was "probably a bit more intense and graphic" than what they had known from similar sea lion deaths previously, she said.
The individual who killed Jade would have been close enough to know they were shooting at a sea lion, and even if they did not, it was "not acceptable" to shoot a gun if you did not know what you were firing at.
"You shouldn’t be making that mistake — and let me be clear, I do not believe in any circumstance that this was a mistake."
In a statement, Doc southern South Island operations director Aaron Fleming said shooting a sea lion was an appalling thing to do and staff were sickened and "genuinely shocked".
A local vet had performed an X-ray and examination, which found about 50 shotgun pellets.
"She was lying down and facing away from the shooter, with most pellets entering her chest and spine."
NZ Sea Lion Trust co-chair Shaun McConkey said after generous donations from the public, the trust had been able to increase the reward on offer for information leading to a successful prosecution to $6000.
Mr McConkey described the killing as a "devastating loss to a small population that has only recently returned to the area".
Doc said that under the Wildlife Act, it was illegal to injure or kill protected native wildlife such as sea lions.
Anyone who did so could face punishments of up to two years’ imprisonment, a fine of up to $250,000, or both.
• Anyone with any information on the incident is asked to contact Doc on 0800362-468.
