This piece, authored by Dr Brett Glencross, was published in the September 2023 edition of International Aquafeed:

Recent approvals by Norway’s Food Safety Authority to allow genetically modified rapeseed oils to be used in salmon feeds in that country are arguably a step-change in the development of GM feed ingredients for aquaculture. However, coinciding with that has been the publication of a sobering paper by the organisations behind the development of that technology, who pointed out that this had been a twenty-year journey [DOI.org/10.3390/su151411327]. So, it has been far from a quick fix and demonstrates how much foresight and commitment are needed for some of these big issue projects. Interestingly, the feed sector was quickly to follow with the comment that they would only consider using the GM oils subject to retail and consumer acceptance, something that to date has still to materialise with any GM feed ingredients in the European aquaculture market. And this is set against a backdrop where new sources of EPA+DHA have never been in higher demand.

However, even before the recent price spike in fish oils, another line being touted about the GM oils was their claims to sustainability superiority over fish oils. However, on closer inspection this argument doesn’t appear to carry much weight either once a proper lifecycle assessment analysis is done. Especially when we consider the current sustainability evidence of small pelagic fisheries, which actually shows that they are among the most sustainable and well managed of all global fisheries [DOI: org/10.1111/faf.12690].  Or when we consider that most of the world’s fish oil production actually comes from by-products from aquaculture or fish caught for human consumption. Indeed, the evidence base for sustainability superiority of any terrestrial agriculture product is somewhat questionable on several grounds. In terms of the carbon-footprint story, a quick review of the GFLI v2.0 database (using economic allocation as per PEFCR-Feed guidelines) we can note that the global warming potential (a.k.a. carbon footprint) value for the British sourced (GB) EF3.1 fish oil value comes to 712 kg CO2-equivalent per tonne, against the corresponding GB EF3.1 crude rapeseed oil of 1808 kg CO2-equivalent per tonne. And that is on an equal tonnage of oil basis. We still need to factor into that the equation that we need three times the amount of the GM rapeseed oil to get the same amount of EPA+DHA. So, arguably the equivalent market supply of EPA+DHA by the GM rapeseed oil is (27/12)*1808 = 4068 kg CO2-equivalent per tonne. When we consider the sustainability in this way, whatever way you look at it the numbers they certainly don’t appear to equal any sustainability argument for a GM oil over fish oils on the carbon footprint front. But then, maybe that is the real issue. All this is not really about sustainability. But rather just reducing or transferring that risk somewhere else.

Fish oil produced from wild fishery by-products in Scotland