A fish tagged by researchers 20 years ago has been found in almost exactly the same spot.
A tag similar to the one found in the snapper. Photo: Supplied / Niwa
The tag was implanted in February 2002 by the National Institute of Water and Atmospheric Research (NIWA) to track snapper stocks.
The snapper. Photo: Supplied / Mr Chilt
The snapper was caught by a person known as Mr Chilt, an amateur jetski fisher, on 27 February in Patea, South Taranaki.
The tag is known as a passive integrated transponder.
Chilt, who recorded the find for his YouTube channel, said it was just another regular day out fishing when he made the discovery.
"I got to my fishing [position], dropped down the old 'ham on the bone' - that's the name of my homemade fishing lure - and began catching big snappers straight away. I released most of them back but took some snapper home with me.
"It wasn't until I started filleting this particular one that I saw the tag and thought 'what the fish is that?' I did a bit of research and found out that it belonged to NIWA, so I contacted them and sent them the tag for inspecting," he said.
When first tagged, the fish was 49cm long and was estimated to weigh around 2.35kg.
Two decades later, it was 65cm long and estimated to weigh 5.17kg.
NIWA fisheries programme leader Dr Darren Parsons said recatching a tagged fish after such a long time was unusual as the tag was positioned in the gut cavity of the animal.
But finding the fish in the same region where it was originally released was not a coincidence, he said.
"The fish has been moving over those 20 years but it follows a seasonal pattern, moving in-shore and off-shore with the seasons for spawning, because that's what a lot of snapper do."
The purpose of the 2002 tagging programme was to estimate the biomass of snapper off the west coast of the North Island, with the data then given to the Ministry of Primary Industries for managing fishery stock targets.
Niwa no longer tags snapper with PITs, with the 2002 programme being the last undertaken, meaning that this snapper was one of the last ever to be given a PIT tag in New Zealand.
The device is the only of its type to have been reported since the early 2000s.