Nelson mussel hatchery research bears fruit with first harvest
Farming mussels has always been a haphazard affair, but now New Zealand scientists have managed to coax them to breed in captivity.
The first of 500 tonnes of the greenshell mussels from a joint Government-private company programme are about to be harvested in the Marlborough Sounds. The research promises to give farmers more control and certainty over growing the indigenous shellfish, worth $350 million to the economy.
Once the programme is in full swing, SPATNZ's hatchery in Nelson could produce about 30,000 tonnes a year of adult mussels, adding $200m value. Last year the industry produced just over 80,000 tonnes.
Traditionally, mussel "babies" or spat washes up on beaches such as 90-Mile Beach attached to seaweed and is bagged for farmers. Sometimes farmers put out lines from buoys and hope the spat will attach to them.
But that has made life difficult for farmers, who have to cross their fingers and hope they will have enough spat for their farms from year to year.
Getting the mussels to give up their secrets was not easy, said scientist and SPATNZ head, Rodney Roberts.
"We experimented with lighting, different bath temperatures and sounds and we finally settled on a combination of light, temperature and small vibrations that seems to really get the mussels going, encouraging them to produce maximum quantities of sperm and eggs."
"We are now able to produce billions of mussel eggs each month and the great news is that these are growing into strong, faster growing and more consistent mussels."
It took two years to take the mussels from spat to fully grown adults.
Marlborough Sounds farmer Bruce Hearn said wild spat differed in quality and quantity, and it was impossible to say with certainty when it would arrive.
"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," Hearn said.
Roberts said consumers would benefit from the captive-reared mussels because they would be a more consistent size. Chefs sometimes find it challenging to get the best results when they have to deal with a range of sizes.
The research was not looking at changing the mussel's taste, but through selective breeding it could open up opportunities in high value areas like nutraceuticals and superfoods.
The SPATNZ hatchery is the result of a collaboration between the Ministry for Primary Industries (MPI) and seafood company, Sanford, through a seven-year Primary Growth Partnership.
Sanford and MPI are each investing $13m into programme, from which Sanford and its contract growers will initially benefit. A requirement is that in time the technology will be shared with everyone in the industry.