Exploring Aquaculture Options for Ōnuku

Jay Whitehead || Shaun Ogilvie || Rik Tainui || John Reid || Carmele Riley

Ōnuku Rūnanga wanted to scope a range of potential aquaculture species for Akaroa Harbour. Based on several hui we identified four key underpinning values that are important for Ōnuku in any aquaculture operation:

1. Maintaining and enhancing Te Taiao (environment),

2. Supporting Oranga (livelihoods) through profitability,

3. Protecting Taonga (things of cultural value),

4. Creating Mahi (employment) for rūnanga members.

We also developed a list of nine potential aquaculture species, from conventional options such as salmon and mussels to less conventional options like seaweeds, all the way through to highly unconventional species such as scampi (a deep-sea NZ lobster).

It is important that the choice of species reflects Ōnuku values. First, we needed to investigate these values in more detail to find out where the rūnanga priorities lay. To do this we used a decision-making process known as a choice experiment using software from 1000minds. The choice experiment was done online, and available to the entire rūnanga to ensure everyone had the opportunity to express their views. The choice experiment process forces participants to prioritise different values, for example, what is more important for aquaculture, money or jobs? This exercise allowed us to assign scores to each value so we could determine how well the aquaculture characteristics of each species aligned.

Key Points

·         From our analyses our advice to Ōnuku would be that mussels or salmon should be considered as top priority species, on the proviso that other species could be considered in future.

·         Of the two species, mussels will be lower cost to set up, will have lower environmental impact (because no feed has to be added to the system) and will have lower financial returns

·         Conversely, salmon will be a higher cost to set up, will have higher potential for environmental impact (because feed has to be added to the system), and will have a much higher potential for revenue return.

·         In terms of salmon, it would make very good sense for Ōnuku to consider a partnership with Akaroa Salmon, as they already have the know-how on aquaculture of this species.

·         Urgency should be given to securing access to new space for the culture of either of the above species.

Mussel Spat

Our experts asked whether this a known mussel spat catching area. It is also important to know  if the volume of spat fall varied with time, and what is the value of the amount of spat that could be captured.  Seasonal and potentially unpredictable - lines may not be in the water all year.

Mussels

Set-up and Running costs and jobs - depend on whether you need to purchase and staff a vessel or if you contract someone to manage the farm. Removal of N from the system. Ecosystem benefits from extra mussel reef and fish habitat beneath and within the farms. Effects on natural habitat - depends on previous seabed disturbance. If previously dredged or trawled, then likely to be positive effects to the seabed in terms of mussel reef forming under the farm. Mussels are sold as commodity product. If can't sell locally and don't have processing facilities, then price would be set by processing companies. Need scale to make money and 16 hectares may not be enough.

Other finfish

Which species? Much higher risk here than salmon as unproven. What are the returns. Potential for risk to wild species higher if farming native species. There may be more researcher jobs while the species to farm is worked out and understood.  Need to consider species that can go to both food service and direct to consumer as well as export (e.g. kingfish flesh oxidises quickly). Set up costs could be high working out how to farm what and then on top of this space would need to produce fingerlings somewhere. May need specialised feeds developed? Unknowns around requirements for disease treatments and interactions with wild populations. Potentially lower market value. Risks of farming a native species - could face farm removal if disease outbreak occur- e.g. Flat oysters in Big Glory Bay. Good potential for Mahinga kai if farming native species.

Oysters

Pacific Oysters - talk to Moana for access to spat and other resources. Explore options for flip-farm https://www.flipfarm.co.nz/. Consider biosecurity risk of the disease bonamia ostreae for flat oysters, and subsequent impact without selective breeding for resilience, where would you obtain spat? If Pacific, typically need finishing or grow out in intertidal or someway of hardening off e.g. flip farm. Could you grow right through your water column to maximise farm space. Probably but would need another space to harden off. Oysters especially flat more valuable than mussels. Consider for Pacific oysters where to get spat. If selective breeding should be virus reliant also hatchery produced enables triploids for year-round harvest.

Salmon

Ōnuku have direct connection with Akaroa Salmon company. Te One Tainui has worked there for many years. Unlikely to have detectable broadscale effects on WQ in the harbour - would require modelling and monitoring to confirm. Still have access to all coastal amenity values – e.g. fishing or diving on nearby reefs. Effects to natural habitat on the seabed depend on level of previous disturbance e.g. sedimentation from land erosion or dredging and trawling. Salmon farming is highly valuable on a per hectare basis. The environmental effects are typically on the area below the salmon farm, these may be able to be managed with appropriate farm management and stocking as well as considering fallowing periods. Also, there may be potential for shared disease between species. Commercial activity to and from salmon farm likely to be a bit higher than shellfish or seaweed. 

Scampi

This species will not be available in the foreseeable future.  Can't see how readily feasible without being land based. Need a seed source. Financial return (cost to grow out relatively unknown but likely to be high as land based). Cost versus sale price needs to be understood and grow out time.

Asparagopsis

Set up costs could be high if need to fund the research that enables seed supply. Unlike karengo, this can be farmed and is native (though not endemic). What is the harvest cycle, likely more than once per year (unlike say mussels). This has potentially positive impact on financial return. 

Karengo

Currently, Karengo unable to be farmed because of current state of fisheries act. Would need permission, some sort of change to regulation to allow. What is the demand? What would be the source of the seed? Would need hatchery to produce seed or catch from wild if permitted and need to know how. There are also unknowns with the value and therefore potential financial returns. Set up costs could be high if need to fund the research that enables seed supply. What is the harvest cycle? For what species e.g. can you harvest more than once per year. If so, financial returns and jobs creation potential may be higher.

Undaria

Needs to be able to compete with existing Chinese market. Will need a large scale to be worth farming. Invasive species. Are our haplotypes (types of this species that are unique to our part of the world) any good on overseas markets? With all the seaweeds there is a question of end-use.  For only food production, will need to have a large farm area.  But for high-value products that are extracted, could get by with a smaller area needed to farm. For the analysis here have assumed the need for a large area, hence will be amenity value and commercial activity negative impacts. Note that nobody is actually farming Undaria at present.