16 May 2015

Mussel breeding

From This Way Up, 12:40 pm on 16 May 2015
Greenshel mussels from Cawthron Institute’s shellfish breeding programme (baby mussels on the right.)

Greenshell™ mussels from Cawthron Institute’s shellfish breeding programme (baby mussels on the right.) Photo: Cawthron Institute

A scientist monitors mussel crop.

A scientist monitors mussel crop. Photo: Cawthron Institute

The New Zealand green-lipped mussel, aka perna canalicula, kuku or the greenshell mussel to use a trademarked term, is a major export earner and a key part of New Zealand's aquaculture industry. But farming them on a commercial scale has its challenges.

Traditionally, seaweed laden with tiny fertilised mussel eggs or spat is harvested from Ninety Mile Beach in Northland, then trucked around the country to mussel farms. An intricate process involving boats, ropes, seaweed and stockings is then used to get them growing, but just a few percent of the spat actually make it to harvest and onto our plates.

Now scientists are trying to do the breeding in the lab and then keep the mussels in nurseries until they're large enough to go into mussel farms. The survival rate of these hatchery-bred mussels could be many times higher than existing aquaculture methods. It would also allow scientists to selectively breed for specific traits, for example mussels that are faster-growing or more meaty.

This Way Up's Simon Morton went to meet Henry Kaspar, who is a mussel breeding specialist and a senior scientist at the Cawthron Institute.

Cawthron Institute aquaculture scientist Henry Kaspar.

Cawthron Institute aquaculture scientist Henry Kaspar. Photo: Cawthron Institute