Natural, selective breeding of Greenshell™

Natural, selective breeding of Greenshell™ mussels at a Nelson hatchery is bringing big improvements in both quantity and quality and opening up exciting opportunities for the industry.

Shellfish Production and Technology New Zealand Ltd (SPATnz) is running the hatchery programme to advance New Zealand’s mussel aquaculture industry.

Sanford and the Ministry for Primary Industries (MPI) are jointly funding the programme through a Primary Growth Partnership (PGP), the results of which will ultimately be shared across the whole industry.

One of the goals has been to find a way to improve on wild spat as a source for mussel farming.

“The difficulty with wild spat is there are so many unknowns: you don’t know when they’re going to turn up, how many there are going to be and how they’re going to perform,” says SPATnz programme manager Rodney Roberts.

At the hatchery, only the best wild Greenshell™ mussels are selected for breeding.

As well as perfecting the right conditions to promote spawning, the hatchery team has worked out how to nurture eggs – which are less than a tenth of millimetre in diameter – through to tiny spat.

“The food they get – microalgae – is a pretty big part of the recipe, along with keeping them healthy and happy. They go through three different growing systems in two months.”

Thanks to steady improvements in equipment and facilities over many years, the hatchery is now at a point where the shellfish can be bred reliably in large enough quantities to be of commercial benefit.

“Other shellfish species are grown in hatcheries overseas but the New Zealand Greenshell™ mussel has been a particularly hard nut to crack. A key element in our success is the hatchery facility that we’ve developed.”

As well as meeting meticulous hygiene and biosecurity standards, the hatchery has been designed and built to be safe, practical and durable in the saltwater environment where it is operating.

“Our lead contractor on the hatchery building, Gibbons Construction Ltd, was awesome at understanding what we needed and delivering without compromising on quality.” A

lot of the equipment and systems inside the building are designed specifically to SPATnz’s needs.

Richmond Fibreglass custom crafted a lot of the hatchery’s mussel growing tanks, while experts at eCAD developed efficient systems for automation, monitoring and alarms that alert staff to problems that could cause major losses.

Mussels that started life at the SPATnz hatchery are now growing on mussel farms throughout Pelorus Sound and being regularly harvested.