AQUACULTURE is fast becoming one of Scotland’s key innovative sectors, with farmed salmon being the largest food export – accounting for around 40% of total value. However, it’s estimated by Zero Waste Scotland that there are around 10,000 tonnes of mortalities each year – fish that goes to waste. This is not only bad from an environmental and ethical viewpoint but is also hitting fish farmers who are already struggling through difficult times.

As the industry continues to grow it is essential that everyone working within it is continually looking at ways to produce fish more sustainably, reduce wastage and reduce our carbon footprint.

Waste levels from average fish hatchery facilities sit between five and eight per cent of total production. We wanted to come up with an alternative and more sustainable way of culling fish to get this figure closer to one percent while also giving the sector an option that would help reduce its carbon footprint.

Fish due to be culled for quality reasons are typically treated with a chemical anaesthesia, which makes them unviable for consumption. They are then incinerated and end up either in landfill or in ensilage bins. A more ethical way of disposing of excess smolts at hatchery facilities is to remove this chemical usage through use of a smolt stunner, with the added benefit of producing an omega rich protein that can be harnessed for new revenue streams.

One of these is the pet food market, which has seen demand for premium options soar since the pandemic as owners choose healthier diets for their pets. Salmon offers a more sustainable source of protein for pet food than the wild fish that are traditionally exploited for this market and is now a viable alternative with stunner technology.

The fish oil market is another that is tipped for significant growth, with the health benefits of omega 3 fatty acids well documented. With increasing demand among the growing 65+ demographic, the global fish oil market size was valued at over £1.3 billion in 2019 and is estimated to reach more than £2 billion by 2027.

The potential across the aquaculture industry is huge. Currently, Scotland produces approximately 55 million smolts a year; with five per cent (excluding natural mortality) culled at an average weight of 35g, it is creating around 105 tonnes of fish bi-product annually. If producers euthanising these fish using a stunner rather than chemical anaesthetic, they could create an additional income stream of approximately £21-£30 million per annum and reduce their carbon footprint dramatically.

With Scotland’s ambition to become a world leader in sustainability, exemplified with the recent hosting of COP26, it is crucial that innovation continues to ramp up, and everyone in the aquaculture industry has their part to play. If we want to remain green leaders longer term than COP26 then we need to keep pioneering responsible marine practices and solutions. Through innovation we can decrease mortalities and turn the blue economy green faster.

Nathan Pyne-Carter, is CEO of Ace Aquatec