Aquaculture and RAS technology: future fuel for humanity?

This article is from Stolten – June 2022

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In a world of 7.9 billion people in need of a nutritious, readily available and sustainable source of protein, one challenge humanity faces is how it will continue to fuel the growing global population.

If more land is needed to grow crops for biofuels, leading to less space being available for grain and to raise livestock, what will that mean for the future of farming? Does aquaculture offer a more sustainable solution?

Oceans under threat

The world’s oceans cover more than 70% of our planet and provide food, play a vital role in regulating the earth’s climate, and are essential to global supply chains. The UN’s Sustainable Development Goals ask governments and organisations to work together to protect our oceans from further harm. Among the issues our blue planet faces are the impacts of plastic pollution, climate change and commercial fishing.

An estimated eight million tonnes of plastic ends up in our oceans each year. Discarded bottles, plastic bags, and packaging endanger marine life, or breaking up into micro-pieces that are swallowed. Over 90% of seabirds are believed to have plastic in their stomachs. However, plastic pollution is just the tip of the iceberg when it comes to threats to our oceans.

Climate change is causing ocean temperatures to rise, changing how fish migrate and destroying coral reefs. Our oceans also absorb much of the carbon dioxide produced by human activity, causing waters to become more acidic and inhospitable to marine life. The result is a reduction in wild fish populations, making the risk of overfishing of wild stocks more likely. This threatens our planet’s capability to supply the population with enough seafood as the oceans simply cannot replenish the stocks at the rate at which they are being fished.

With so many challenges to overcome, sustainable land-based aquaculture has an important role to play in helping to protect the world’s oceans, which are so vital to the future of our planet. “Respect for the environment in the development of sustainable fish farming facilities are key values for Stolt Sea Farm,” says Sustainability and Quality Manager at Stolt Sea Farm, Carlos Tavares (pictured).

“Not only can our farms directly help to reduce the pressure on wild fish populations, but we are also committed to reducing our use of plastics and the amount of waste we produce across all our operations."

Protein power

Aquaculture is an increasingly important source of safe, nutritious, and sustainable seafood for people worldwide. According to, global aquaculture production must double by 2030 to keep pace with demand. Fish aren’t simply a much healthier source of protein than meat; they have a relatively small impact on the environment too. As they are cold-blooded and supported by the buoyancy of water, fish need fewer calories for growth from food than other livestock.

As one of the world’s most advanced high-tech aquaculture companies, Stolt Sea Farm uses pioneering land-based techniques to produce seafood, including RAS technology, which offers high levels of control, safety and reliability. So, what does RAS technology involve and how can it help fuel future generations at the same time as minimising the impact of food production on the planet?

50 years of investing in innovation

2022 marks the 50th anniversary of Stolt Sea Farm’s operations. Throughout that time, it has invested in designing technology that can consistently produce some of the most difficult to farm species.

Recirculating Aquaculture System – or RAS as it’s more commonly known – is one of those innovations, offering a sustainable fish farming and aquarium technology that enables sea life to thrive in a controlled environment. It is usually deployed at locations where water supply is limited or the quality of the local water supply is not high enough, and although generally more expensive than conventional systems, its benefits far outweigh the increased set-up costs.

Engineering and Maintenance Manager at Stolt Sea Farm, Roberto Canosa explains: “RAS technology has been steadily implemented in fish farming during the past few years and Stolt Sea Farm was one of the first to develop its own unique technology during 20 years of ongoing investment in R&D.

"Our farms specialise in particularly difficult to farm species – turbot and sole. The constant purification and recirculation of water from the tanks significantly reduces water usage and conserves energy, making it a highly energy-efficient process. Furthermore, the design of our RAS significantly reduces the need for fish handling, improving welfare conditions.

“The recirculating water undergoes several filtration steps, and one or more microbiological treatments to lower the amount of suspended solids and organic matter, and biological oxygen demand. This is followed by oxygenation of the water and finally, the pH of the water is checked, and temperature controls put in place. In a nutshell, the water from the fish tanks is filtered mechanically to remove the majority of any solids, before biological treatments are used to rebalance and purify the water further.”

Consistently producing the highest quality turbot and sole is, however, not quite as easy as Roberto makes it sound. He adds: “High water recycling rates can increase nitrate levels in the water, so everything must be closely monitored, managed and maintained by our team at all times. The purification systems work to exact requirements, specifically designed by Stolt Sea Farm’s experts who have developed their knowledge over many years. And all our operators receive ongoing training so that they understand how to keep things running smoothly and safely.”

Sustainability benefits

Sustainability and Quality Manager at Stolt Sea Farm, Carlos Tavares is responsible for ensuring that the Company stays true to its sustainability commitments, which go beyond protecting the environment. He explains: “As a consequence of population growth, the demand for healthy food is also increasing, which provides fish farms an opportunity to supply an alternative and stable source of protein. We follow rigorous quality and environmental controls to ensure everything we do is environmentally sound. Our GlobalGAP certification confirms that we have in place sound and responsible aquaculture practices.

“For us it’s not simply about meeting the legal requirements, we want to be at the forefront of producing a sustainable source of healthy protein. We were the first in our industry to achieve ISO 9001 Quality Management certification for both our production and commercialisation facilities, as well as ISO 14001 certification for environmental management.”

Providing secure jobs in rural areas

While for some it might seem that sustainability is the latest ‘fad’ to reach the agenda of boardrooms across the globe, for the team at Stolt Sea Farm it’s something that has been a part of the Company’s DNA right from the very beginning. Having a positive and wide-reaching impact, not only on the environment but on the wider community.

“Ours is a business with a wide concept of sustainability,” says Rubén Faraldo (pictured), Stolt Sea Farm’s Fish Division Director. “One of our strategic objectives is the development of sustainable operations that will provide local communities with good jobs, employment security and ongoing training for another 50 years and beyond.

"I’m confident that we will achieve that goal. Aquaculture is a growing industry offering stable job opportunities and we are committed to investing in training and further improving working conditions to support the next wave of aquaculture employees.”

Stolt Sea Farm: fast facts

  • Established in 1972
  • Over 400 employees
  • Brands: Prodemar™, King Turbot™ and King Sole™
  • Leading global player in both sole and turbot farming
  • Europe’s largest producer of turbot and sole by market share
  • 14 farms and two hatcheries across five countries (Spain, Portugal, France, Norway, Iceland)
  • Fully integrated value chain from R&D and broodstock development to processing, sales and marketing
  • Unrivalled for quality and size consistency
  • Products sold to more than 30 countries, delivering daily across Europe
  • Fresh fish is delivered within 72 hours of ordering

Our premium species: turbot and sole

Turbot is a delicious and healthy fish that is enjoyed by consumers worldwide. It is highly regarded for its delicate flavour and bright white flesh. Sole is one of the most versatile fish for cooking. Although not an endangered species, sole has suffered severe overfishing in certain parts of the world, with some fisheries on the verge of collapse. Both turbot and sole contain important nutrients, including vitamin B, calcium, fluoride, magnesium, iodine and omega-3 fatty acids.

This article is from

Stolten – June 2022

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