Mussel Breeding at the Cawthron Institute

Cawthron Aquaculture Park has a comprehensive research programme and works in collaboration with greenshell mussel commercial entities. The latest phase in a long involvement with this species is aimed at identifying and breeding from more stress-tolerant and efficient mussel families, along with selection for more desirable traits in colour, taste, texture and size.

Cawthron Institute is New Zealand’s largest independent research institute specialising in freshwater and coastal marine species, environmental research and research for food and aquaculture industries. It also has substantial testing laboratories and provides seafood safety testing for key sectors of the aquaculture industry.

Cawthron Institute scientists were the first to breed the NZ greenlipped mussel in confinement. They developed and proved many of the techniques which are used in NZ to produce $300 million in sales annually, most of it from export. Currently all mussel seed is collected from the wild, making it difficult to guarantee supply and quality. Mussel seed is only available a few times a year, which makes for an erratic supply if things go wrong. In collaboration with the government Cawthron now hosts SPATnz (Shellfish Production and Technology New Zealand Limited), a company which will enable mussels to be grown from hatchery seed that have been specifically selected for desirable characteristics such as health promoting benefits, rather than from wild spat. The improved genetics from the research and trial programmes will also be commercially available to the industry from SPATnz.

SPATnz has begun with a pilot-scale hatchery, with the first spat scheduled to be produced in 2015. SPATnz is a Sanford subsidiary, which is part of a Primary Growth Partnership contract for $13 million each of public and industry funding invested over seven years. It has been hailed as the most significant research, development and commercialisation investment made in New Zealand’s greenshell mussel industry since the first marine farms were established in the 1970s. Hatchery spat can be produced on demand using selectively bred broodstock of consistent quality that will provide the mussel industry with the benefits enjoyed by almost every other primary producer.

Norman Ragg works in the aquaculture group at the Cawthron Aquaculture Park measuring mussel stress responses, metabolism and growth rates to identify the most robust and efficient animals of the species. One method is to create an energy budget, describing how effectively different mussels use their food. The process resembles a human health lab: heart rate and respiration may be monitored, along with the quantity and quality of food eaten. Creating the food is a whole field of research in its own right, with a Cawthron team dedicated to the intensive production of ‘gourmet’ micro-algae to feed these fussy shellfish.

Culture technology combined with natural breeding techniques gives the opportunity to create mussel breeding lines with up to 20% growth improvement every generation, according to Dr Ragg. With the new techniques now being applied in the ‘Mussel Gym’, Cawthron aim to ensure that resilient and efficient strains are also made available to the industry.