Using its broad base of capability, NIWA is creating a new aquaculture species for New Zealand - hāpuku - for sale in the world's fine dining sector.
Scientific name: Polyprion oxygeneios
Māori name: hāpuku
Hāpuku is a member of the Polyprionidae or wreckfish family, which is comprised of nine species of large, demersal fish. Hāpuku is large and thick bodied, reaches 150 cm in length and can vary in colour from silver and blue, to a pink, brown, and silver combination.
Most often found in deep waters over a depth range of 50 to 854 metres, this fish species is found throughout southern waters and is common in the waters around New Zealand and Australia. Where stocks are still abundant (such as the Chatham Islands) the species is known to frequent shallow waters.
Unlike kingfish, hāpuku is a winter spawning species producing eggs in late July to early September.
Significant interest has been demonstrated globally for development of this species for aquaculture. In Europe, and Spain in particular, a very similar species of wreckfish, Polyprion americanus, is highly prized and considered to be a local delicacy. As a result, Polyprion spp. have been over-fished in most locales. Its premium market position, high value, and limited supply have created interest in the aquaculture sector.
Likewise there is strong interest here in New Zealand with strong commercial interest driven by strong markets for this species both locally in New Zealand and Australia, and internationally in Europe and Asia. In Japan, for instance, hāpuku is well known as the highly prized sashimi product known as Minami-osuzuki.
How is NIWA research establishing hāpuku aquaculture?
Since 2003, NIWA has accumulated the world's largest broodstock resource for hāpuku. The broodstocks are held in large spawning tanks (with 45-75 tonnes) at our Bream Bay Aquaculture Park. Each tank has its own controlled environment, designed to maintain optimum temperature and light regimes natural spawning.
We have now progressed our way through every aspect of hatchery technology development for hāpuku. The hurdles encountered have in general been similar to those of other commercialised finfish species our team has worked on (halibut, turbot, sea bass, and sea bream), but with specific solutions developed for the early rearing of hāpuku.
The main technical hurdles overcome have been:
- stable broodstock husbandry
- the system design for the successful incubation of egg and yolk-sac larvae
- initiation of first feeding
- the transition from live to formulated feeds to produce weaned juveniles ready for on-growing and transfer to sea.
Our trial using the extensive culture systems at Bream Bay, to emulate a range of potential environments in NZ are base-lining the performance for hāpuku ready for industry uptake. These early on-growing trials are revealing the considerable growth potential of this species.
NIWA research: future-proofing for hāpuku
Our broodstock selection programme, running since 2007, is showing us which broodstock are producing the surviving F1 generation and indeed our F1’s are reliably producing F2’s. Once the industry develops NIWA will be able to apply its expertise in this area to select for desirable performance traits. The aim is to maintain the competitive edge for hāpuku farming as it proliferates and, indeed, overall for New Zealand's aquaculture sector.