"You could see all the ribs, you could see the pelvis, the spinal column. It had no blubber and was sitting with its fins under its body trying to thermoregulate."
The seal also had a barb lodged in the side of its head.
"We believe it was from a spiny-dogfish so it obviously made a poor dinner decision."
Lambregts erected fencing and cones around the area the seal was in so it couldn't be disturbed by dogs and members of the public.
Wellington Zoo confirmed it sent veterinary experts from The Nest Te Kōhanga to assess the seal this morning.
Lambregts said the decision was made to euthanise the seal given its malnutrition and very weak state.
"At least the decision was made and its not still sitting there in pain and suffering."
The seal was sedated and taken away this morning.
The Department of Conservation said the vet who assessed the seal did not believe removing the spine would improve its chances of survival.
Science adviser Laura Boren said it was unlikely the barb was directly related to the seal's condition.
"Also, if we did remove it, there was no guarantee he would actually be able to recover because his body condition was so poor. So in that situation, it was decided the most humane thing to do was to euthanise it."
"The seal is now at rest and is not suffering any more."
Boren said it was common during this time of year to see seals coming ashore.
She said people should give them space, especially if they were in poor condition so they could rest and recover.
Seals were usually pretty resilient, Boren said.
