Farming Pāua - the black pearl of the ocean

A Bluff-based operation is farming cocktail-sized pāua using the pristine waters of Foveaux Strait.

The New Zealand Abalone Company (TNZAC) is hoping to sell two million of the mini pāua every year.

If you turn up to TNZAC pāua farm in Bluff, expect a few quick facts.

If you want to prevent a pāua from sticking itself to a surface, just lick its foot.

Pāua don't have a mechanism to clot their own blood so if you nick one it will die.

They're the only black abalone in the world, are highly prized in Asia and are known as the black pearl of the ocean.

And, most importantly, only 2 percent of pāua larvae make it to adulthood.

That, says TNZAC's Linda Smith, makes paua precious.

"Pāua larvae, they start the size of a dust mite."

She says it takes a pāua more than ten years in the wild to reach sexual maturity.

"We like to reiterate time and time again to people to make sure they are not taking our little guys. Those are really, really important."

TNZAC's pāua farm is based in the former Ocean Beach freezing works with Foveaux Strait at its back door and is currently growing hundreds of thousands of tiny pāua that will be harvested at 'cocktail' size - between 50 and 80 mm.

Pāua can be legally taken from the ocean at 125mm.

Linda says the farmed pāua are bred from stock taken under the quota system from Stewart Island.

The goal is to harvest 2 million mini-pāua a year - about 200 thousand tonnes - and supply the New Zealand market first before offering it to export markets.

TNZAC's marine scientist  Morgan Vanimannan says farming pāua can control their survivability rate.

"If you think about it, what are the chances that fertilisation is going to occur first thing in that whole body of water out there and how do they survive from predators. That's why there's only a very slim chance they will make it to adulthood."

Naturally, pāua feed on seaweed and diatoms but at the farm, they are also given a formulated feed.  It has been developed by Morgan.

Linda says it's the first time feed designed for pāua has been developed in New Zealand.

The farmed pāua will reach harvestable size in about four years which is less than half the time it would take them to grow to the same size in the wild.

"You can provide the nutrition you want to provide them with where you know it's going to boost their growth and immunity," Morgan says.

The plant and animal-based artificial feed is adapted for the different stages of a pāua's life.

"At the end of the day you are what you eat," says Morgan. "So in terms of how we can market the product  we absolutely know what this paua has been feeding on so if you were a customer and you had demands that you wanted it to be fully organic we can customise it for you."

The first harvest will take place in 2023 or 2024.