The potential of hybrid flow-through technology
Hybrid flow-through technology has great potential for growth, according to a recent report.
Possibly the biggest long-term constraint on the growth of aquaculture, especially salmon, is the limited space available for new fish farms. According to a report from the analysts at Rabobank, one solution could be the wider adoption of hybrid flow-through technology.
The report, “Going with the flow”, was published in November last year. It argues: “The key question at this point is not whether HFS will demonstrate viability, but rather how quickly production will expand, in what regions, and what long-term implications it will bring for the salmon industry.”
Farming in sea cages exposes the fish to a variety of risks in the marine environment, from sea lice and bacteria to harmful algal blooms. Production in this way also arguably presents risks for the environment, and planning restrictions on locating fish farms at sea mean the capacity for growth is limited.
Recirculating aquaculture systems (RAS) mean that, in theory at least, salmon can be grown in almost any location as long as there is a supply of water and energy, but the energy and capital costs for these projects can be prohibitively high.
Flow-through technology in aquaculture is well established, and has been used for many years to raise fish like trout, tilapia, catfish and salmon smolts. The new generation of HFS aquaculture facilities is, however, on an altogether larger scale, Rabobank says.
With HFS, between 30% and 80% of the farm’s water is pumped in fresh every day. This means that, while it still needs to be filtered to keep out parasites and pathogens, complex oxygenation, temperature control and biofilter systems are not required.
The evidence also suggests that the greater biosecurity in a hybrid flow-through system leads to better product quality. Salmon Evolution reports that 90% to 96% of its harvest has been rated as “superior” quality, compared with 75%-85% in traditional net pan salmon farming.
Rabobank argues that the higher energy costs involved in HFS are outweighed by the advantages of improved biosecurity.
The report notes that Norway, the world’s superpower in terms of salmon production, is the leader in HFS but adds that Iceland, a latecomer to the industry, is becoming a “second hub” for HFS.
In Iceland, rather than pumping in water from the open sea as is typical in Norway, the most common approach is to use water from wells in the lava rocks that are part of the country’s coastline. This approach means that the water is already subject to natural filtration and has a stable temperature.
The report suggests that Chile, Canada, Scotland, North America and the Faroe Islands are all candidates for investment in HFS farming.
For HFS to reach its full potential, however, the report says two areas need to be addressed: legislation and capital. For capital, some strategic investors have backed HFS schemes (including large feed companies, food retailers and processors), but the large salmon-producing companies have not yet thrown their weight behind this technology.
Legislation is currently more of a hindrance than a help. Even in Norway, the report notes, a block has been imposed on new licences pending the ratification of a new law in the country’s parliament.
The report says, however: “Our expectation is that once there is a better understanding of the good financial and environmental performance of the existing HFS projects, more legislators and local communities will become supportive of this form of aquaculture.”
An industry pioneer
Salmon Evolution operates an HFS (also known as HFT – hybrid flow-through) salmon farm at Indre Harøy on the Norwegian coast.
The company’s Chief Executive, Trond Håkon Schaug-Pettersen, says: “A hybrid flow-through system basically captures the benefits in both a RAS and a full flow-through facility and is in our view really the sweet spot when it comes to choice of technology.
“What we try to achieve with HFT is basically three things:
• First we want to create an optimal environment for the fish where we can achieve the full growth potential of the salmon.
• Second: We want to operate with as low as possible risk
• And finally we want to have a system that minimises the effect of an accident.”
He explains that HFT achieves this by using a large amount of fresh seawater at all times, having observed that a higher level of new water has a positive impact on the growth of the fish. About a third of the water in the system is always new seawater while reusing about two-thirds.
He adds: “By not exceeding a reuse level of two-thirds, we don’t have to introduce advanced water treatment systems such as a biofilter, and hence we can operate with a lower risk, because the higher you go on the recirculation level, the higher complexity and also risk. The only thing we do besides providing new seawater is that we aerate the water for CO2 and add oxygen, both of which have been done in the smolt industry in Norway for decades.”
The system is also able to maintain stable and ideal temperatures for the fish all year around, so the company maintains the same production in February and March as in August/September.
The Salmon Evolution system is designed in a way such that each tank is an individual biozone, meaning that water in one tank is never in contact with water from the other tanks, which improves biosecurity.
Schaug-Pettersen is optimistic that the new land-based regulatory regime due to come in this year in Norway will be good for the industry. He says: “Basically, this is a perfect fit for HFT the way it is proposed. I think this will reduce regulatory risk significantly and provide good visibility for the industry to grow going forward.
“In other markets, the regulatory process is much more an uncharted territory so this needs to be put in place.”
In terms of capital, he argues that this should become less of a challenge as the industry matures, but adds that Salmon Evolution has a big advantage as a front-runner.
A third factor, he stresses, will be the availability of competent people with the skills to run an HFT facility.
Icelandic opportunities
Jens Þórðarson is CEO of GeoSalmo, which is building a hybrid flow-through salmon farm on the south coast of Iceland.
The farming facility will ultimately be capable of producing up to 24,000 tonnes annually, with production expected to start in 2026. The initial phase of the project will produce roughly 7,500 tonnes and the first products are expected to launch in 2027.
Þórðarson comments: “Regarding the capital costs, it depends on the comparison. The capital cost of HFT is comparable to many other land-based solutions but of course higher than sea-based costs. The benefits compared to sea-based are drastically lower risk and a very stable, industrialised production system and the ability to benefit from continuous improvement over time. Also, sea-based licences are rarely available anymore, and increasingly there is also a significant acquisition cost for the licences as they are a limited resource.
“Regarding energy costs, these will be mitigated in some way as these systems develop but one of the reasons Iceland is an exceptionally good place for this industry is that the country is an energy island and this allows for a very long-term view from the energy companies who can offer fixed contract prices spanning very long periods. Energy is probably an issue with most other locations.”
Looking to the future, he predicts: “I am reasonably confident that within five to10 years the industry will start to see significant growth. However, it is likely to happen slower than the ambition of many companies due to permitting and access to capital.
“The technology approach and supplier base needs to mature quite a bit for this to happen so that more standardised, proven solutions can be deployed. Once that maturity has been reached, we believe the industry to be a very attractive infrastructure-like business.”
Going with the flow: The rise of hybrid flow-through aquaculture (Rabobank, November 2024).
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