Dr. Andrew Weston, marine biologist and aquaculture innovator, is trying to revolutionize RAS technology, based on a founding principle: maximum efficiency and minimum waste.
New Recirculating Aquaculture System (RAS)
In the Scottish coastal town of St Andrews, Dr Andrew Wheatstone and his team are working to develop a profitable, low-risk and, most importantly, truly sustainable recirculating aquaculture system (RAS).
Andrew has worked in research in the field of aquaculture, public aquariums and the ornamental fish industry, with a focus on eliminating waste and inefficiencies through practical science. Prior to starting his current efforts, he was involved in the development of the UK's first sustainable shrimp farm in Balfron. However, British Shrimp, the parent company to which Wheatton's R&D division belongs, closed in 2021, and his spin-off project, Great British Aquatic Technology, closed shortly thereafter.
However, the closure sparked the formation of RAStech, an innovative company run by Andrew, his wife Sarah, his son David, and the rest of his team. The goal of the RAStech team is to develop a sustainable, profitable and low-risk land-based aquaculture method.
Andrew's desire to achieve a sustainable RAS has to do with what he calls the word "sustainability" itself, as he does not believe that any current aquaculture operation is truly sustainable. On shrimp farming – RAStech's current focus – Andrew lists a range of issues: from nutrient contamination and antibiotic overuse to mangrove destruction and modern slavery.
That's where he intends to make a change.
1. A new system for shrimp farming
Andrew's innovative approach to RAS technology consists in eliminating system inefficiencies from the ground up.
Living in an area where many farmers use polyethylene tunnels to provide a warm growing environment for soft fruits such as strawberries, Andrew was inspired to adopt a standard polyethylene tunnel design, reinforcing the structure, insulating it with a plastic layer spun from 600mm recycled beverage bottles and covering it with plastic sheets. Combined with glued floor panels (radon and methane), a hermetically sealed structure is formed.
He explains: "[The design] gives us a very good insulated building. It can be very, very warm or very cold inside, depending on what environment you want. So that we can start from here and keep the temperature down and not too much of a concern for us. ”
RAStech is designed to provide high thermal efficiency, even in harsh winter conditions.
According to Andrew, RAStech is designed to reduce heat consumption by up to 95% compared to traditional shrimp RAS facilities, and more importantly, the entire unit can be packed in a standard container and transported to any part of the world for use.
"It's definitely a big savings, and the phenomenon that used to require a lot of electricity for heating is no longer there – we got rid of it," he lamented. ”
In addition to the low energy requirements of his system, Andrew's goal is to reduce waste associated with wastewater treatment. In his system, everything is harvested and can function, even the biosolids left behind by the farmed species – in this case the shrimp.
The organic sludge collected from the wastewater is used to fuel the anaerobic digester to produce methane, which can be burned in the boiler to generate heat for the system. The remaining highly nutrient water can be used as a biostimulant, and the RAStech team is currently testing it for growing salt-tolerant crops and seaweed, extracting excess nutrients from the water. Andrew says that in this process, the water can be reused and cleaner than it was at the beginning.
"There's an attitude in industry that if we do something that's good for the environment, we're going to spend more money – that's not necessarily true," he said. Yes, there are some very expensive things you can do for the environment that may not be economically viable for businesses, but there are also simple, common-sense things that you can do that are good for both parties. ”
"We usually use about 10 percent of the water that a normal RAS uses, because normally you drain a lot of water, but we don't."
The RAStech team aims to eliminate inefficiencies at every production point
Andrew pioneered what he calls "boring RAS" – a slow-growing but steadily growing business platform – expressed excitement about the prospect of expanding his business and the commercial sale of shrimp farmed in his pilot system. Achieving this milestone compared to the current scale of the business will demonstrate the viability of his technology in the aquaculture industry, not only for shrimp, but on a wider scale. Despite the economic risks associated with scaling up, Andrew is relieved by the UK's 53,000 tonnes of prawn market per year.
In terms of competition, Andrew seems to be comfortable with the market, both for his shrimp and for his technology, as it stands, as it stands, although he commented that the market is very competitive. In his opinion, there is enough demand to support all promising players.
"There's plenty of room for everyone now. In the next 10 years, that's likely to change, but right now, I wouldn't say that, I think what we're doing is very different from what other people are doing. I think we're very unusual, and I wouldn't say we have a direct one-on-one competitor right now. ”
RAStech is expanding its commercialization.
2. Challenges of recirculating aquaculture
Considering the exciting prospects ahead, Andrew reflects on the challenges he faced in the development of the project. Andrew said the main hurdles RAStech has faced so far appear to stem from the conservative nature of the aquaculture industry itself. Many members of the industry have been critical of the company's goals, arguing that this advanced approach to energy and resource conservation does not make sense.
With the cost of one of the RAS's most expensive inputs skyrocketing in the wake of the ongoing energy crisis, there seems to be a greater understanding of what Andrew is trying to achieve, although he comments that there may still be some way to go.
"I think we may be premature, but I think our time is coming."
Another challenge that the RAStech team faced and seemed to overcome was the lack of commercial shrimp hatcheries in the UK. The majority of the shrimp grown in the UK comes from US hatcheries, which can lead to some inconvenient issues in addition to a huge environmental footprint and a mouth-watering price tag.
Andrew explains: "Unfortunately, hatcheries in the U.S. are all located in Hurricane Lane, either in Texas or Florida. This isn't too good because they get squashed on a regular basis, which can mess up your market for a while. Shrimp disease is also prevalent in these parts of the world, so there is always a concern about the disease, and I think it's a big challenge. ”
Andrew, who has been farming his own shrimp on a small scale for the past few years, believes that setting up a commercial-scale hatchery in the UK is the only way to safely and securely support the domestic shrimp industry. However, raising capital for this can be challenging, as the development of commercial hatcheries relies on a thriving industry to create demand, and the current industry cannot expand significantly without hatcheries.
Andrews's desire for sustainable, clean and economically viable RAS technology is indisputable, and while his vision for a practically self-sufficient British prawn industry is indeed ambitious, it does sound likely.