Department of Conservation staff went gold-fishing in Albert Town yesterday, hauling more than 100 of the fish from the Wanaka suburb's Riverside Park pond.
The fish were caught in nets and appeared to be in very good health. Several were estimated to weigh at least half a kilogram.
Dunedin ranger Daniel Jack said the fish were almost ready to spawn and that added some urgency to the task of removing them.
Doc was concerned the fish might escape into the nearby Albert Town lagoon, then into the Clutha River and ultimately into Lake Dunstan, where they would compete with other fish species, such as trout.
Mr Jack said it would have been difficult to remove the fish from the much larger lagoon and virtually impossible to eradicate them from Lake Dunstan.
Conservation services manager Chris Sydney believes the goldfish were put into the Albert Town pond deliberately by someone emptying a private pond or aquarium.
Under most circumstances, it is illegal to release fish into waterways without approval.
Mr Jack said he expected to catch most of the fish alive in nets over the next few days and they were being transferred to a pond well away from the Clutha.
