x Abu Dhabi, UAEFriday 28 July 2017

Better oysters a matter of breeding

Aquaculture experts in New Zealand may revolutionise the industry by breeding wild with cultured varieties to make a tastier delicacy.

Olin Pilcher checks on the progress of oyster spat at the Cawthron Institute.
Olin Pilcher checks on the progress of oyster spat at the Cawthron Institute.

NELSON, NEW ZEALAND // A search for plumper, meatier oysters has led to the transformation of the mollusc industry in New Zealand. The country's only selective breeding programme is producing millions of baby shellfish for domestic and international consumption. The project, near the city of Nelson, began a decade ago and is sponsored by the Cawthron Institute, a trust owned by the local community that is mating Pacific oysters with "good-looking" uncultivated varieties to create a genetically diverse stock of a consistent quality that will attract high prices.

Most of New Zealand's baby oysters, or spats, are born in the wild while the Nelson venture aims to create a new domesticated industry. The initiative provides 20 per cent of the nation's supply, selling its products to specialist farms in other parts of the country where they will continue to grow for up to 12 months before ending up on the dining table. The facility breeds up to nine million spats every year but is capable of producing up to 50m as it seeks to become a profitable enterprise.

"They just look like sand when they first come across to the nursery and they grow into gravel, basically," said Olin Pilcher, the project manager. "It's like growing rocks, it really is." "The larval stage is really intense and that takes three weeks. Once they're in the spat stage, the older they get, the hardier they are and the less sleepless nights you have. It's a long process. "It is difficult, it's intensive. The fact that you're dealing with biology and live animals is always a challenge. Any little hiccups can turn into major problems. Everyone who works here is passionate about it, so you need that passion to come out in the middle of the night if the power goes out. I am part of a pioneering team and I'm really looking forward to the future," Mr Pilcher said at Cawthron's coastal hatchery, which lies on a wind-swept flood plain 13km north-east of Nelson.

The baby oysters are kept in concrete tanks laid across a series of ponds which are filled to the brim at high tide when special gates are opened to allow seawater to surge through large pipes. At low tide the process is reversed and the water is drained to replicate the tidal shifts the immature shellfish would experience in the wild. The designer specimens start life in a large shed where single plastic water containers, less than half the size of a normal bathtub, are home to millions of larvae. They look like groups of inert grains of sand but under a microscope they emerge as energetic, semi-transparent creatures shaped like irregular circles with minuscule whiskers which buzz around like dodgem cars.

"The primary aim is to make a better all-round half-shell oyster," said Mr Pilcher. "That market is where the premium prices are. It comes down to presentation, which is shell shape and colour and the key aspects are fatness of the meat across the shell and we can get that partially through breeding." The marine molluscs are treated like minute kings and queens. Their surroundings are subject to precise temperature control and the lighting is carefully monitored while the larvae sit in finely filtered seawater and are fed a diet of what researchers call "gourmet algae" and other nutrients. When they are about the size of a child's tooth the youngsters are worth only a few cents each, while the finished product will cost about NZ$2 (Dh3.7) in restaurants.

Daryl Wehner, Cawthron's commercial and investment manager, is optimistic that the baby oyster project will become a commercial success. "It would absolutely revolutionise the industry," he said. "I'd like to think this would put us on the world stage as far as the New Zealand oyster is concerned. It is exciting." "The proceeds that we have received from sales of the spat have been reinvested back into the research. We are fairly well advanced towards creating a commercially viable venture. We're pretty confident because of the productivity gains and the premium product we have."

Aquaculture is a significant contributor to the local economy. Nelson, a city of 42,000 people, has the biggest fishing port in New Zealand and marine farming generates millions of dollars. Craig Dennis, the chairman of the region's chamber of commerce, said the Cawthron Institute's selective oyster breeding programme could provide substantial benefits. "It's important for the future," Mr Dennis said. "The research attracts world-class scientists to the region and they do world-class work."

"To control seafood harvesting this way is absolutely critical and we've got lots of success stories in the region around that, not just with oysters but scallops, mussels and salmon." "It is a competitive world out there. New Zealand's farming industries are well ahead of most other countries from a produce per square hectare perspective. A key reason for that is innovation and science," he said.

pmercer@thenational.ae