Aquaculture news

Greenshellâ„¢ mussels
30 March 2014

Case Study: Transforming a national delicacy into export gold

Fresh, marinated, smoked or barbequed whichever way you enjoy them, the iconic Greenshell™ mussel is a delicious and irresistible New Zealand seafood.

Behind this export delicacy enjoyed the world over, is the story of a remarkable transformation.

Taking on the challenge

For decades, the Greenshell™ mussel industry relied solely on seed collected from the wild to supply their stocks.

While this wild spat helped the industry grow to where it is today, it is inconsistent and unreliable – not ideal when building up export markets. But, while many mussel farmers dreamed of a consistent supply of healthy hatchery spat to support wild caught stocks, they never thought it was possible.

Now, thanks to 20 years of industry commitment, Government investment and a team of very clever scientists – that dream is becoming reality. Soon, mussel farmers will begin to choose from the hatchery the type of mussels that they will grow and export to market.

Science finds the answer

The story of the Greenshell™ mussels' transformation from wild to domesticated animal began in 1993 – with an idea.

"I started wondering why the mussel industry was still using wild animals as their stock, when other farming practices had been selectively breeding for desirable traits for centuries," says Cawthron Institute senior scientist Dr Henry Kaspar.

At the time, it was widely believed it would be too difficult to breed Greenshell™ mussels in a hatchery. But Dr Kaspar and his colleagues weren't swayed.

"We've always had the attitude at Cawthron that just because no one else in the world has done it, doesn't mean it can't be done – and this was no different."

Government investment underpins research

In 1993, with industry backing, Cawthron Institute applied to the Government for funding to explore the possibility further. With a grant of $260,000 the research project was launched.

The outcomes of that early research lead to the first trials in selective breeding of Greenshell™ mussel families. The results of those trials were clear - selective breeding of mussels could work.

Since then the Government has invested a further $10 million in Cawthron's Greenshell™ mussel research, which is now helping New Zealand realise the huge growth potential of this $250 million industry.

World-first innovations

Along the way, several innovative processes have been developed by the Cawthron team. One of these was a new way to grow baby mussels in small plastic tanks, a world-first innovation that has set the standard for shellfish breeding and is now referred to internationally as the CUDLS system (Cawthron ultra density larval system).

Cawthron has used this system to push the boundaries for spat production, resulting in dramatic increases in efficiency and reliability. Industry have picked up this technology and worked with Cawthron to take it to commercial scale.

Over the past 20 years, with industry and Government backing, Cawthron scientists have also been able to achieve a host of world-first achievements for mussel breeding, from being the first to successfully grow substantial quantities of Greenshell™ mussel spat in a hatchery, to becoming global experts in breeding for selected traits.

"The more we know about mussels, the easier it is to breed for strength, survival, taste and appearance. Our science is helping make Greenshell™ Mussels even more valuable and desirable than they already are," says Cawthron Cultured Shellfish Programme manager and scientist Nick King.

Making science work for industry

Industry have been key partners in this project from the start - from their input into breeding programme direction and assistance with field trials, to developing the scale-up methods that will turn science into commercial benefits. One of these partnerships, BreedCo, will see industry and Cawthron roll the breeding programme out for commercial brood stock supply.

Since the beginning, Cawthron scientists have been conscious of producing the kinds of mussels the industry wants. Nick King and his team work closely with the mussel industry to ensure they breed for traits according to economic value. For example, some markets prefer the colour of female mussels.

"Producing all female crops means more money for the farmer, for the same effort," says Mr King.

Taking science to market

Commercial-scale production is the final step in the Greenshell™ mussel's transformation, and where Government and industry are now playing a leading role. The Ministry of Primary Industries is investing $13 million over seven years to match funding by Shellfish Production and Technology New Zealand Limited (SPATnz) owned by Sanford Limited.

This funds research under a Primary Growth Partnership Programme to develop methods for commercial scale Greenshell™ mussel spat production and selective breeding. A pilot scale mussel hatchery will be built at Cawthron Aquaculture Park north of Nelson, and research will be undertaken to scale-up spat production methods. If that research is successful, then SPATnz hopes to expand capacity to produce sufficient spat for 30,000 tonnes of Greenshell™ mussel harvest by 2019.

There are huge benefits to large-scale production says SPATnz Operations Manager Dan McCall.

"It will improve the consistency of product, speed up production cycles and provide security of spat supply."

The next phase

While Cawthron has proven that selective breeding can provide big gains for aquaculture, it is by no means the end and the story of the Greenshell™ mussel's transformation continues to evolve.

Spat with improved performance will soon be produced in large quantities for commercial testing and industry will have the security of knowing that there is another option for spat production if disease ever affects wild spat, which is vital when the Greenshell™ Mussel industry has grown to be the largest single seafood item exported from New Zealand.

Dr Kaspar says Cawthron scientists will continue to inform and support the industry's growth, including looking at exciting future opportunities such as the use of molecular techniques for screening families of mussels.

"There is always more we do. Our goal is to always look for tomorrow's opportunities."


The Challenges:

1. Breed Greenshell Mussels in a controlled environment

2. Selectively breed Greenshell™ mussels for commercially desirable traits

1993 - 1999 Cawthron scientists work on closing the life cycle of the Greenshell™ mussel and use that information to work out how to breed them in an artificial environment. First Government funding to support the project.

2000 – 2002 Successful breeding of Greenshell™ mussels in hatchery conditions confirmed. Cawthron explores commercial possibilities for selective breeding with Government investment.

2003 – 2008 Research into scaling up breeding for industry requirements and selective breeding for commercial traits begins. Major Government financial backing secured towards selective breeding research with Plant and Food Research and cryo-preservation of shellfish.

2009 – 2012 Glenhaven Aquaculture Centre developed at the Glen, north of Nelson. Aquaculture research facilities expanded. Mussel companies form SPATnz and work together on research and development. SPATnz secures funding for Primary Growth Partnership programme with the MPI at Cawthron Aquaculture Park.

2013 - 2014 Pilot scale commercial hatchery built at Cawthron Aquaculture Park to develop methods for reliable commercial scale spat supply.

2015 - 2019 SPATnz aims to scale-up to provide methods capable of producing spat for 30,000 tonnes a year of Greenshell™ mussels. Cawthron research and selective breeding continues.

The outcomes: World-first successful breeding and selective breeding of Greenshell™ mussels in a controlled environment using world-leading technology and methods. Scalable hatchery systems established to provide long-term industry benefits and underpin commercial production.