Hatchery-reared selective-breeding mussels lead aqua-industry more sustainable, profitable in New Zealand

Situated on a remote, quiet and scenic coast in Marlborough Sounds, South Island of New Zealand, SPATnz hatchery has made Greenshell mussel breeding hatchery more sustainable and profitable.

According to figures of stats NZ, the export revenue of Greenshell mussel last year was 287.7 million NZD.

SPATnz stands for shellfish production and technology. It is a scientific program collaboration between Ministry of Primary Industries (MPI) and Sanford, a fishing company of New Zealand with a century long history.

Greenshell mussel is a very common-seen sea product in New Zealand. They are naturally sustainable and with good culinary qualities. Besides, mussel oil and powder have great potential in nutraceutical business. But how to raise mussels more economically and environmental-sustainably was a question haunted Kiwi mussel farmers for decades.

Although a single female mussel could produce more than 1 billion eggs throughout lifetime, very few of them could survive in nature. The headache for farming mussels was that people had to get the spat (baby mussels) through wild catch, which allows little control over the timing and quantity of spat supply or the characteristics of the crop.

SPATnz General Manager Rodney Roberts said, "Normally these mussels breed in the wild and we wait for their babies, known as spat, to wash up on beaches attached to seaweed or land on catch ropes. That made life difficult for New Zealand mussel farmers, who had to cross their fingers and hope they would have enough spat for their farms from year to year."

But now, with selective-breeding technology adopted by experts from SPATnz hatchery, mussels farming stepped onto a new stage.

"We use traditional selective breeding, on top of that, DNA fingerprinting, which is genome sequencing that helps us understand the biology of the animal so we will take full control of the breeding process."

"The program is not aiming to produce a single 'super mussel' but to maintain a wide range of high performing lines to choose from. It is different from genetic engineering," said the manager.

With the selective-breeding technology, scientists settled on a combination of light and temperature to encourage mussels to produce with maximum quantities and best quality of sperm and eggs.

According to Ministry of Primary Industries (MPI) of New Zealand, the most striking improvements, especially in terms of commercial value to mussel farmers, are the certainty of supply spats comparing with the wild catch, much faster growth of selectively bred mussels, and uniformity of mussel size and quality.

Mussel farmers are excited about the results. Bruce Hearn, who farms in the Marlborough Sounds said, "One of the advantages of hatchery spat is that we will know when we are getting it and we can plan for it. That will make a huge difference."

In addition, as to period of a mussel's maturity from a seed size around 50 mm to sale size, it usually takes 31 to 36 months in the wild but under 17 months for the hatchery selective seeds.

The effectiveness and certainty for baby mussel production in hatchery brings huge profits to the business.

Sanford, one of the oldest and biggest fishing companies in New Zealand, as well as the co-sponsors for SPATnz program, secured profitable paid-off.

The sales figure from the company's 2020 annual report shows that mussels was the second largest sales of the company, and mussel overall sales revenue grew steadily due to the strong demand from China and U.S. markets in particular despite of COVID-19 pandemic.

The technology is more than commercially valuable indeed.

Experts believe that the mussel breeding program could help mitigate the impact of climate change on the aquaculture sector. The technology also helped the mussel industry against threats like ocean acidification and disease.

An independent evaluation report issued in 2020 said it also brought benefits to nature. Thanks for the effectiveness of baby mussels produced in the hatchery, aquaculture has been altered the way it was by minimizing the costs of wild-catch mussel seeds in terms of transport, sorting and disposal.

And growers can seed ropes in suitable growing sites at higher density by lighter touch on the nature.

Given that roughly only 20 percent of mussel farms throughout New Zealand have adopted SPATnz technology so far, Roberts predicts the commercial potential of the technology will be very optimistic.

For instance, he believes that a Marine Extracts Centre will increase the capacity to produce high value products through mussels.

Actually, Sanford acquired a mussel powder company and commenced developing its nutraceutical business, and this will drive more demand for spat in future. (1 New Zealand dollar equals 0.6958 U.S. dollar)