The classic line from a famous song first penned in the 1940s, "16 tons and what do you get", has its answer in Masterton, at the new sewage-treatment plant of all places.
Sixteen tonnes of eels have been transferred from the old ponds to the new ones, and that's not all.
Another eight tonnes have been harvested and taken to a private landowner's dam.
Transferring the eels between the ponds was a logistical exercise. Nets had to be set in the old ponds in the early evenings and just before dawn, now laden with squirming, threshing eels, they had to be hauled about 30 metres so that the catch could be introduced to their new home.
The Masterton District Council estimates 38,000 to 40,000 eels have been relocated. They ranged in length from 20cm to 1.2 metres and in weight from 200g to the big boys who weighed in at up to 3kg.
As the treatment plant was being developed, the council acknowledged the significance of eels to Maori. With Kahungunu representatives, the council formed a working group alongside other interested parties to manage the eel population at the Homebush site.
The iwi representatives on the working group were said to be passionate about the value to the environment of the Homebush eels and not just in terms of the small eco-system of the ponds.
Future generations of eels, and the health and wellbeing of the wider environment are, in a small way, dependent on the Homebush eels.
As they mature, the eels will leave the ponds and begin the journey to Tonga, where they breed.
Elver return and find habitats around New Zealand, where they mature and begin the cycle again.