Throughout the growing cycle, we feed our salmon diets specially designed to meet these same nutritional needs but in a way that actively tries to minimise impact on the environment.

The raw materials for these specialist diets come primarily from two key sources: marine ingredients and plant-based ingredients.

Marine ingredients

Fishmeal and fish oil are the marine ingredients that provide the long-chain Omega-3s found to benefit human heart health, brain function and blood circulation.

In the wild, Atlantic salmon obtain these Omega-3s by eating smaller oily fish, whereas our farmed salmon are fed a combination of fishmeal and fish oil made from both:

  • Wild-caught fish
    Typically, species that would not be fished in significant quantities for human consumption. These are sourced from producers certified to a minimum of the MarinTrust Standard (formerly the IFFO RS Standard); a certification which enables producers of raw materials in the fishmeal and fish oil sectors to demonstrate responsible practice. This includes ensuring that marine ingredients are sourced from responsibly managed fisheries and that they are fully traceable.
  • Processing trimmings and by-products
    For example, skin, flesh, viscera (internal organs) and blood from fish other than salmon, all of which are also sourced from MarinTrust Standard certified producers.

Amongst our next goals, when it comes to feed, is to obtain further external certification and source an even higher proportion of by-products from fish trimmings.

Plant-based sources

These can include cereals, oilseed crops and legumes, amongst others, all of which are certified non-GMO and originate from approved raw material suppliers under the Feed Materials Assurance Scheme (FEMAS). This ensures that they are approved as being safe for use in animal feed in the EU.

Another plant-based protein is soy protein concentrate which is sourced from ProTerra certified sustainable producers. This guarantees that a product or its ingredients have been produced responsibly – both environmentally and socially – and without the use of genetically modified crops or products.

Other essential nutrients

Beyond protein, Atlantic salmon also have a need for other essential vitamins and minerals. Our specialist feed suppliers put every effort into ensuring these micronutrients are sourced from equally safe and sustainable sources, using suppliers who are accredited by the Quality and Feed Safety Management System for Specialty Feed Ingredients (FAMI-QS).

Relying less on marine ingredients

In 2021, thanks to ongoing work with our specialist feed partners to produce high-performing diets that rely less on marine ingredients but still meet the nutritional needs of our fish, we achieved our lowest use of fishmeal and fish oil yet.

Our Scottish Sea Farms diet – administered at seawater stage and accounting for 87% of all feed used in 2021 – consisted of just 23% marine ingredients versus 77% plant-based or other sources.

Add in our freshwater feed (3% of total feed used) and Label Rouge feed (the remaining 10% of total feed used) and across all our farming activities in 2021 we used 27% marine ingredients versus 73% plant-based and others.

Furthermore, 45% of all raw materials used in our feed are sourced from within the UK, while all marine ingredients are independently certified by the MarinTrust Standard and/or the Marine Stewardship Council (MSC) as being responsibly sourced and responsibly produced.

How salmon farming compares

Salmon farming is considered to have one of the best feed-to-edible-meat ratios of all the farming sectors globally.

One of the most widely quoted measures when determining the sustainability of a particular farming method is to look at the feed conversion ratio (FCR) – the ratio of animal feed that goes in versus the weight of fish produced.

In the case of farmed salmon, this animal feed would contain fishmeal and fish oil.

Calculations by former IFFO Technical Director Andrew Jackson (2015) suggest that each kilo of wild fish used in farmed fish diets, including salmon, produces 4.5 kilos of farmed fish. That’s currently amongst the highest return of any of the farming sectors.

Drilling down a stage further, a second key measure when assessing the efficiency of marine ingredient use to produce farmed salmon is what’s known as the fish in fish out ratio (FIFO); the amount of wild fish used to produce each kilo of farmed salmon.

IFFO quote this as being 0.82:1 which would suggest that more farmed salmon are produced than wild fish used; a ratio reflective of the fact that salmon farmers now recognise the finite supply of fishmeal and fish oil and increasingly seek to introduce more plant-based ingredients into salmon diets.

You can read more about how these ratios were calculated here.