SCOTLAND’S salmon industry could make an extra £23 million a year selling fish guts as health supplements, according to a new study.

Researchers at the University of Stirling’s Institute of Aquaculture also recommended better marketing of fish heads, skins, trimmings and “frames” – which means bones with attached flesh and blood.

Working alongside experts from the University of Massachusetts, the Stirling experts found that the total value of by-products could increase by 803 per cent if salmon farms were to “maximise edible yields and introduce better separation at the processing stage”.

The would add 5.5 per cent to the annual yield of the salmon industry in Scotland, the research found.

Fish heads, guts, and other trimmings are a potentially important resource, known to contain valuable nutrients.

These include minerals, vitamins, protein and lipid fractions (long chain omega-3 fatty acids), which can support further processing into a range of products.

Julien Stevens, of Stirling University, said: “We hope this research leads to improvements.

“There is a need for further infrastructure investment and policy support to incentivise resource efficiency, along with greater transparency on the current uses of by-products within the sector.”

The scientists used figures from 2015 and found that, by combining primary products (54 per cent yield), with the maximum potential by-product food yield (around 23 per cent), it results in 132,171 tonnes of food.

The remaining by-products, minus blood water (4.3 per cent) are then utilised in the important production of fishmeal and fish oil.

These are then subsequently used in aquafeed for farm raised marine species.

In this example, accounting for that material in feed for European seabass and gilthead seabream, would result in 148,691 tonnes of total edible yield compared to the original production of 92,081 tonnes of salmon.

Scotland’s aqua- culture industry already contributes more than £1.8 billion annually to the economy.

It also supports around 8,800 jobs, many in remote and rural areas.

Now the industry is looking to maximise the potential with research showing that could contribute up to £3.6bn every year by 2030.