Optimising the sustainability of fish farming in Scotland

2 September 2021

Innogen researchers have published a report that examines how innovations in fish farming can contribute to meet multiple government policies and objectives, including Net Zero, a circular economy, zero waste, marine and land biodiversity targets and UN Sustainable Development Goals.

As the global demand for fish has increased over the past 40 years, so has farmed fish production. Aquaculture production now surpasses wild-caught seafood for human consumption. Farmed salmon is Scotland’s and the UK’s biggest food export by value and ensuring that the sector achieves its expected growth targets sustainably will require policies that support innovation.

“Although the aquaculture industry has made huge strides in becoming more sustainable, there is still room for improvement”, says Amy McGoohan a PhD student based in the Global Academy of Agriculture and Food Security at The University of Edinburgh and lead author of the report.

The report is based on information available in published literature and from industry and policy representatives. It identifies several areas of opportunity that will contribute to reduce the sector’s greenhouse gas emissions as well as benefit land and marine biodiversity such as: innovations in fish feed, fish farming systems, fish processing, and waste and by-product optimisation. The report offers some recommendations to policy-makers to aid the implementation of these innovations and realise their potential.

“Innovation in feed production has the greatest opportunity to contribute to fish farming’s climate change mitigation and to improve biodiversity-related impacts”, says Joyce Tait, co-author and co-Director of Innogen.

Fish feed accounts for over 90% of the industry’s greenhouse gas emissions and between 40-75% of total production costs. In Scotland, fish diets contain roughly the same amount of plant-based ingredients (soya meal and rapeseed oil) and marine-based ingredients (fishmeal and fish oil from wild capture fisheries). New feed ingredients could mitigate the effects of these feed sources on biodiversity and climate change. Micro-algae, insects and microorganisms that use waste residues and by-products as feedstocks offer alternative sources of protein with a lower carbon footprint. Evidence to date indicates that they have a comparable nutritional profile to fishmeal. Cost, scale-up and regulatory challenges currently preclude the widespread use of these novel feed ingredients.

New production systems are also being designed to increase production capacity, reduce environmental impacts, meet planning-related challenges, and improve fish health. Although they are likely to have greater energy demands, and therefore greenhouse gas emissions, than those currently in use, these demands could be met by using renewable energy solutions rather than fossil fuels.

Food processing innovations, such as the introduction of reusable bulk bins for transport and biodegradable packaging, are beginning to have an impact on the environmental footprint of aquaculture. Similarly, new uses for wastes and by-products are helping the sector transition to a circular economy and could lead to new revenue streams.

The report argues that a better understanding of the complexity of interactions across the entire fish farming value chain will help guide policy interventions and research support to areas where there is clear evidence that the expected improvements in sustainability will be delivered. The approach should focus on the options with the biggest potential gains and those where synergistic interactions between different innovation initiatives could facilitate development and multiply positive outcomes.

“Innovative technologies are key to shifting food production systems towards achieving net-zero emissions as part of a circular bio-economy”, says Tait. “Coordinating the development of both effective methodologies and standards for their application will help ensure comparability across different analyses.”

The report was funded by The Open University and can be accessed in full here: https://www.innogen.ac.uk/media/304

Executive summary: https://www.innogen.ac.uk/sites/default/files/2021-08/Scottish%20Aquaculture%20Innovations_OU%20Executive%20Summary.pdf